Air Temperature Senor Modification (With Pic's)

Here's an easy way to relocate your air temperature sensor, out of the hot engine compartment, to the much cooler inner fender. This should take you about an 1/2 hour, requires NO DRILLING, NO WIRE CUTTING, and will cost less than $1.

1) Remove the temperature sensor from the air intake tube, and disconnect plug.

2) Remove both halves of the airbox.

3) Remove the intake tube from the fender.

4) Remove the drivers corner light.

5) Locate the new hole for the temperature sensor (see small round hole in middle of pic)

http://www.grovestreet.com/jsp/onepic.jsp?id=116583

6) Remove gromet from the air temperature sensor and install an 1/16" thick rubber washer. BE CAREFUL NOT TO TOUCH SENSITIVE BLUE RESISTOR!!!

http://www.grovestreet.com/jsp/onepic.jsp?id=116584

7) Install sensor in the new location, and secure it with the stock gromet.

http://www.grovestreet.com/jsp/onepic.jsp?id=116585

8) Re-route air temperature plug/wire to new location (yes the stock wire is long enough), and hook it up. Secure wire with a cable tie.

http://www.grovestreet.com/jsp/onepic.jsp?id=116586

9) Re-install the stock airbox/intake tube, corner light, and plug up old sensor hole with a 1/2" electrical box plug (bought at Home Depot).

http://www.grovestreet.com/jsp/onepic.jsp?id=116587

When I performed this mod, together with the air intake mod I posted earlier, I definitly felt an increase in performance. The truck now feels quicker and more responsive. I'll report back with a gas mileage report after a couple of tankfulls. Enjoy the mod!

Just curious why this would work? The air temp sensor is to tell the computer the temperture of the incoming air. Sooo, if it thinks its cooler that actual, the engine will run either lean or rich. Assuming you say you get more power(which is hard to tell by the seat of your pants), so I would think it would go to the rich side, and your milage would go to crap since you are wasting fuel. I'm no xactly sure what the ECU doesn with the air temp info, just kind of thinking out loud. I'm curious what your milage turns out o be, and what others think of this mod. I don't see why moving the air temp sensor would help performance.
John

I believe the computer retards the timing some when the temp sensor senses warmer air in order to help prevent preignition. If you fool the sensor into thinking the air is cooler than it actually is then you might be able to get a bit more power through more timing advance. However, I would expect that you may experience some preignition and the liklihood that you have to run premium fuel is increased. As it is, adding the K&N AirCharger messed with soemthing so I get preignition something horrible if I run regular unleaded on hot days, so I have been running premium. Doesn't bother me since my previous vehicle required it and I'm use to buying it, but a lot of people here are pretty cheap when it comes to fuel. I could manually adjust the timing back a little, but I'd rather just get the premium gas.

Anyway, I would definately drive with your windows donw for awhile and listen for pinging. Turn the A/C on too and listen, as the extra load of the A/C could be enough to put you over the edge.

Rather than continually speculate, perhaps someone with a service manual can tell us what it *actually* does.

From the 2000 Xterra Electronic Service Manual (ESM)

Component Description NGEC0066
The intake air temperature sensor is mounted to the air duct housing. The sensor detects intake air temperature and transmits a signal to the ECM. The temperature sensing unit uses a thermistor which is sensitive to the change in temperature. Electrical resistance of the thermistor decreases in response to the temperature rise.

Real descriptive.

*paul, the programming in the ECU what's important and that isn't something that would be in the ESM. Your right everyone here is speculating, but the only way to know how the ECU is going to behave is to have it's code, engineering specs from Nissan, or trial and error study of it's behavior. We know some of it's behaviour, i.e. it retards timing to prevent knock. So, the guesses are reasonable. Xterrian with the OBD scanner and his onboard computer could experiment and probably see what things change if you change the inlet temp sensor location.

Wow, I didn't mean to open a can of worms here. Moving the air temperature sensor is a popular modification, performed for years, for engines with modified intakes/exhausts. Some have even changed out the thermistor (with a different rated resistor) to fool the engine into thinking it's taking in air at 32 degrees. Now the air temperature sensor's job is to monitor the incoming air temp, and relay that info to the ECM, where the information is processed to determine the correct fuel/timing setting for that temperature. Heat soak is the main issue here, we all know how hot that engine compartment gets. By moving the sensor out of the extra hot engine compartment closer to the actual outside temperature, people have experienced an increase in engine response. This mod only relocates the stock temp sensor to a location that is less affected from the engine heat. I am currently running an K&N drop in filter in my slightly modified stock airbox, a Gibson S.S. exhaust, NGK BKR6EIX Iridium plugs (one step colder than stock), 8.5mm wires, timing is @12 degrees BTDC, and I'm running 87 octane only. So far, I have not experienced any engine knock (on a 90+ hot day with the AC on), but it's to soon for a report on gas mileage. I'll let you know as soon as I find out.

Hmmm? Oddly enough, my wife and I were discussing this very topic yesterday. I was demonstrating the capability of the OBD II scanner and told her I could check on the outside temp. I pulled up the intake air temp and it was 134 degrees. I thought that was a bit high(it was actually in the 90s). I tried to figure out where it was getting such hot air from. The air box under the fender shouldn't be that hot, but maybe getting baked in the hot sun could do that. So in my case the temp the engine is getting should be lower, but instead of moving the sensor, I should move the intake of air, so I actually get colder air. Maybe I can run my scanner in Carlton's truck during GOX and see if the snorkel helps get cooler air to the engine.

OK, I just went out and played with the software. I can create a log of up to four parameters. What four things should we check? I figure intake temp will be one, then timing. What others should we watch? Probably have to have rpm in there to qualify the results. Maybe coolant temp as well? Let me know and I'll do a little test run and post the results here.

Is pinging accompanied by a power loss?

Typically yes. Not directly because of the pinging, but because the computer retards the spark and/or makes the fuel mix richer.

And it would be difficult to hear without the windows down?

I would add fuel/air ratio or something that indicates how much fuel is being added or cut from the mixture.

I don't have a clue here...is the air temp sensor you are talking about the same one that gives the reading for the electronic temp/compass gage on the overhead console? I was going to relocate that sensor to get more accurate readings of outside air temp, but if that also effects the engine performance then I don't think I'll mess with it.

Completely different systems. The temp/compass sensor is supposedly in front of the radiator, but I'm not sure exactly where. I've never tracked it down. The temp sensor we're talking about plugs into the airbox your air filter is in.

These are the parameters I can choose from for logging:
Calculated load
Coolant Temperature
Manifold Absolute Pressure
Engine RPM
Speed
Ignition Advance
Intake Air Temp
Airflow
Gas Mileage
Throttle Position
O2 Sensor Voltage X 4

Unfortunately it only checks the fuel system (pressure, mixture, closed loop etc) at the initialization of the ECU connection. Any of those listed above that you want to throw in the log? We should probably do the test with the vehicle stopped, to prevent other variables from coming into play. We should have ignition advance in there too I guess. Any suggestions, information, scenarios you guys want. I'm just enjoying seeing all this info in real time so I'm completely open to suggestion.

If you fool the ecm into thinking the air is cooler (denser) it may richen the fuel mixture to keep the air/fuel ratio correct. Since the air really is not denser the mixture will be too rich. This will give a little gain in power but increases emissions and will most likely hurt mileage.
Just my $.02

There is not much point in testing at *idle* or reving unloaded if you are looking for the effect of the intake temp sensor on power or ign timing. It's going to be very hard to "dyno" your engine while driving, esp w/ an auto.

Since the air flow is already measured on a mass basis, and the target A/F ratio is mass-air/mass fuel, then intake air density is already compensated for. There is a possibility that either the MAF sensor needs to be temperature compensated (to be accurate,) or that the air temp sensor provides a secondary function such as cold start duration.

I would be a little surprised if ignition timing is already so close to the limit that it needs further adjustment by intake air temp (but perhaps it is.) I have a factory service manual for a '91 (truck) VG30E and it does not have an intake air temp sensor, but the MAF is the hot wire type. I think we have the "thick film" type.

Why not drop the sensor in a cup of ice water stuffed in near the air cleaner, then drive around and see if you prefer the performance?

I would probably take readings with it at idle and parked with the sensor in the intake and again with the sensor out of the intake. Every reading from the ECU will change and be unrepeatable if I drive around or even touch the gas pedal. I should probably do three or four sessions either way. That way I can see what changes and since the only difference between the sessions would be temp sensor location I imagine we can safely assume that any changes in the readings would be due to the positioning of the sensor.

If rich enough I imagine it would eventually do a number on your cats too. The cats are only a last resort to take out the last little bit of emmissions. The more they have to work, the shorter their life.

The dealer told me my truck was running too lean, so maybe isolating my sensor better from engine heat actually would help me?

It will be interesting to see what Xterrian comes up with.

I should add that I have a temperature sensor installed right next to my intake and the temperature (according to the guage) sometimes reaches 150 degrees or more. I really need to find a way to better isolate the engine heat.

Running the intake configuration I have, and moving the air temp sensor to the fender, my intensions were not to "fool" the ECM into thinking the air is cooler than it really is. My concern was engine compartment heat soak, and moving the sensor the the inner fender (right next to the air intakes), I feel would now more accuratly reflect the true outside air temp. IF I were running a cone filter, drawing hot air from the engine compartment, I could see moving the air temp sensor to a different location WOULD be "fooling" the ECM.

The real test will be if your gas mileage increases or decreases. Any mileage numbers yet??

The air temp sensor is in the airflow, so it is giving the true temp of the air feeding the engine. Nissan has programed the ECU to account for the actual temp. Moving it is fooling the ECU. If this is what you want to do that is fine, just don't fool yourself into believing that you are fixing something that the engineers at Nissan didn't see. The sensor is measuring the actual air temp even if you've made intake modifications, unless you have added a fresh air intake after the sensor that draws cooler or hotter air from somewhere else. I will perform an experiment today and post my results. I will log the RPM, Intake Air Temp, Ignition Advance and Coolant Temperature. I will make 3 logs with the sensor in the stock location and 3 logs with the air sensor outside of the stock location, in a cooler area.

Not to be a smart ass, but can you prove this? It's hard to have faith in the engineers at Nissan after placing the altenator on the lowest part of the engine. :rolleyes: Can you prove they took into account heat soak when they decided to place the sensor where they did?

Quote:

Moving it is fooling the ECU. If this is what you want to do that is fine, just don't fool yourself into believing that you are fixing something that the engineers at Nissan didn't see.

See above. I still disagree with you on this issue. In my close to stock setup, the air temp sensor IS measuring the actual air temp, minus any heat from the engine. I will be very interested to see your data where it compares actual air temp to sensor readings.

I can't believe you'd have that much faith in Nissan design. As discussed before the engineers may have taken that into account, but some bean counter somewhere probably decided they could save .25 cents by mounting it within the engine bay to use less wiring.

If I'm not mistaken, the V6 Xterra draws air in through the fender well to the air box? If that is the case then putting the temp sensor in the engine bay is causing it to read a higher temp than the actual air coming in. Moving it to the fender well would correct this.

I've not looked at the air intake at all on the Xterra, so I'll check it out tonight when I get home to see if my hunch is correct.

Ok, I did my little test. With the sensor in the stock location the averages were:
RPM 870-900
Coolant Temp 180 degrees F
Ignition Advance 15 degrees
Intake Air Temp 125 degrees F

With the sensor in a glass with ice:
RPM 870-900
Coolant Temp 180 degrees F
Ignition Advance 15 degrees
Intake Air Temp 60 degrees F

With the sensor in the fender behind the turn signal:
RPM 870-900
Coolant Temp 180 degrees F
Ignition Advance 15 degrees
Intake Air Temp 150 degrees F

Apparently placing the sensor in the fender actually increases its perceived temp because there is no airflow. There is no marked change in performance noted either way. There was no change in RPM as would be noted if the air/fuel mixture had changed by an appreciable factor. I ran the engine for 10 minutes in each scenario. Plenty of time for it to reach equilibrium. If you perceive an increase in performance, go for it, as perception is reality for you.

Your "little test" is flawed. The truck was parked running at only about 900 RPM. How can you get any airflow into the fender (around the corner light and from the well) if you weren't moving? Perceive that.

There is no flaw except for your thinking. It doesn't matter if the truck is moving or not, there will remain the same temperature difference. The same air flowing through the closed in fender is going into the intake. The temperature difference still won't make a perceivable difference in how the truck runs. Feel free to continue thinking you are smarter than the Nissan Engineer that does this shit for a living. If you want to show you're smarter and a better engineer, then move the alternator to the top of the engine. Once you figure out how to do that I will copy your modification and pat your back, until then I will stay with the Nissan guys. They have actually done something useful and built the Xterra.

Well said...

I guess you don't read very well. I clearly stated in the first post that moding the intake TOGETHER with moving the air temp sensor, I felt an increase in performance. Second you contradict yourself in saying in an earlier post that the temperature difference measured is higher because of a lack of airflow in the fender, now you say "It doesn't matter if the truck is moving or not, there will remain the same temperature difference". Which statement are you going by? Of course it matters if your moving or not. Sitting in the hot sun, stuck in traffic, are you saying the air temp in the fender will not increase? Now for your "little test", did you mount the temp sensor the same way I did (including sealing the holes leading to the engine compartment? Why would the sensor read 60 degrees if you had it in a cup of ice? I hate to say it (mmm...no I don't), but I have to question your test and the results. Remember, your the one here with a hair across your ass about this mod. It sounds like you could care less if this mod will help with performace or not, you just want to prove me wrong. Keep trying.

Actual tests are always the best way to tell if a mod works. Obviously this mod does not. Even considering the fact that the vehicle is stationary, take a look at the numbers from the test with the temp sensor in a glass of ice. Even at 60 degree air reading the Ignition Advance values did not change.

That's proof enough for me that this mod will not make any performance difference.

You seem to have gone back and read my posts a second time. You should probably read a third time. Your reading comprehension is thwarted by your desire to be right. I stated that it was hotter in the fender than the intake due to the airflow over the sensor. The same air that is in the fender is going in the intake. Ok, this may be complicated for you so I will try to make it so you can understand. Truck standing still:
Under fender temp, 150.
Intake temp, 134
This is probably due to the fact that the 150 degree air under the fender is being drawn into the intake, lowering it's relative pressure and decreasing its temperature(basic physics, it's how the AC works). So no matter how fast you drive, the temperature in the intake will always be lower than the temperature under the fender. Do you get it now?
The sensor measured 60 degrees in the cup of ice under the hood. I live in the desert where the air outside is 90-100 degrees. I didn't immerse the sensor in water, I just placed it in a cup of ice, so the 150 degree air in the engine compartment was cooled to 60 degrees by the ice. The big point that you seem to be missing is that all of this is irrelevant. There isn't any significant change in the engine's performance either positive or negative noted by moving the temp sensor. I think the problem is that you spent money, time, loss of warranty, possible engine damage and loss of fuel economy modifying your truck and won't see any real benefit for it. Take it to a dyno and give us some numbers. Come to GOX and I'll hook the OBD II scanner up and we can see together if the numbers change appreciably between your truck and a stock Xterra. I admit that the scanner isn't going to show what a dyno would, but I'm confident that you have hurt your performance if anything. You insist on believing that Nissan spent a bunch of money on parts that your truck doesn't need and that hurt performance. Hell, those cheap bastards didn't put a passenger door lock on post '00 trucks just to save money. You think they put all that plastic under the hood for looks? Your best bet is to just keep fooling yourself into believing that your mods are the shiznit and you are the Einstein of engine performance mods. Why not put a variable resistor in the line and just turn it up when you need to pass on the highway? :rolleyes:
By the way, I could care less if you insist on fucking your truck up. I just don't like you coming here and trying to convince others to jump off the cliff with you. If my testing had shown any difference either positive or negative I would have posted it. I don't like your inference that I skewed the results to prove you wrong. The fact of the matter is that you are wrong. If you were right I would have posted that you were right. I would be right either way so there is no benefit for me to say you are wrong unless you are.

Wow, someone's got their panties in a bunch. I only started this thread as a possible performance gain. I never said I was expert on engine mods. By the way, you STILL haven't addressed the potential heak soak issue.

Quote:

By the way, I could care less if you insist on fucking your truck up. I just don't like you coming here and trying to convince others to jump off the cliff with you.

Why the fuck would I want to cause damage to my or another members truck? A big "Fuck You" if you think that was my intentions. I put this out on the table to get feedback, and/or possible ideas for improvement, not shit from some asshole's assumpsions on my intent. I highly doubt either of these mods will cause damage. So far I have NOT experienced any ill-effects or loss of gas mileage. As for warranty, ANY modification will void it for that part/system. If you don't like the mod, don't do it. No one's pointing a gun to your head. The only way to prove this is to: a) Conduct your test with the truck actually MOVING, and the RPM's between 2000 - 3000, b) I get some dyno results.

Who's panties are in a bunch? I never said you were intentionally doing it. I think you are doing it out of ignorance and pride.
I gave you feedback and you refused to believe it. I gave you an idea for improvement, don't waste your time with it. Refusing to believe it's true is one thing, but your snotty attitude is agravating. "Perceive that"

I'm sure that will be sufficient gaurantee to all those that copy you to get your, "increased performance".
"So far".

All the more reason not to do it unless there is a definate improvement that can outweigh the loss of warranty.

Don't worry, I wont. I just hope some other poor fool doesn't think this does something and screw their warranty for nothing as well.

What difference will it make if the truck is moving? Yes dyno results will prove it. I don't think you would believe those either. I admire that you have been experimenting with your truck. Who knows, you may stumble on to something? I just don't think this is it. By the way, when you have a discussion with someone, they are more likely to treat you with respect if you show a little, fuckwad.

All I'm waiting for now are boxing gloves...

Read the tagline...

I can't believe what a douch bag your being about this whole thing. I've only defended my position about these mods against your demeaning remarks. Right from the begining you started on me with the "preceived" notions I experienced, and when I would counter, you act like a little bitch. Why are you the only one I've had a problem with over this? Why treat my idea as if it came from some ignorant ricer-boy? Am I just supposed to roll-over and let you make fun of me. Respect is earned buddy, and you haven't earned jack shit from me.

We should probably bring this to the ALR if it's going to continue. That being said, I didn't know if your mod was good or bad I just wanted to help out with my new toy. I gave ample opportunity for everyone to give input on what sort of testing I should do within the confines of my equipment. I did the testing when I didn't actually have the time to(trying to get my truck ready for the trip to GOX). I posted my results stating that I didn't see a difference no matter where the sensor was. I stated that any performance increase was probably a perceived increase. It is common for people to perceive a non existant increase in performance after they work on their truck. I think my truck feels peppier after I clean my K&N. Is it peppier? Probably not. That doesn't mean I'm an idiot and your perceived performance increase doesn't mean you're an idiot either. You however, felt a need to defend that and insist it wasn't a perceived increase, it was an actual one. Unless your ass has a built in accelerometer, you don't know it for a fact. I might have let that pass, but you felt a need to be a smartass about it with your, "Perceive that" comment. I only replied in kind. Be a man, suck it up, accept the facts or prove your point with oposing facts, not just a feeling. Don't get your panties in a wad and insult people trying to help you and they probably won't insult you back.

No we don't have to bring this to the ALR, I'm through fighting about this. If you can't see that the "Perceive this" comment was in response to your prior demeaning post, there's nothing else I can say. I put this post up with good intentions, and all you could do was to put it down. I'm going to conduct my own experiment using RTD's from work and will measure the temp of the stock location, new location, and engine compartment myself. And if I'm wrong, so be it, I don't have a problem admitting it. All I wanted to do was share my idea with the others on this board, not get into a pissing contest.

I'll look forward to your post. I'd be interested in seeing the actual temperatures. I've always thought the ECU shows them to be higher than they actually are. I'm pretty sure that it's irrelevant to our discussion though. It didn't seem to make a difference to the other parameters no matter what it was. I just wish my OBD II scanner would show actual air/fuel ratios. The RPM never changed appreciably, so I assume that the air/fuel ratio didn't either, but I could be wrong.

An hour of research on the web (naturally ignoring the ricer and aftermarket dribble) tells me that intake air temp (and manifold pressure) are used to apply minor corrective maps to the base fuel injection duration and timing maps. As most here acknowledge, it's in your best interest to let it do its job.

I don't see any problem with the stock location, provided you have the stock air box. It's *not* sensing the underhood heat.

If you don't have the stock airbox (or have modified it such that it looks like a Home Depot plumbing display ) any other location that's directly in the airflow is going to be substantially equivalent.

If you want to advance the ignition timing, just do it at the distributor! Most engines don't give you that option, and is probably why fooling the sensor is a popular mod.

On his picture site the following modifications are listed:

Gibson Stainless Steel Exhaust System
Bilstein Shocks (Front & Rear)
Calmini Idler Arm Brace
Aurora 8.5 mm Wires (Red)
NGK BKR6EIX Iridium Plugs
Nissan Tail Lamp Guards
WAAG Silver Sportster Push Bar
Hella 500 Clear Fog Lights
K&N 33-2031-2 Air Filter
JL Audio 500/5 Amp
JL Audio 10W0 10" Subwoofer/Custom Box
Rockford Fosgate FRC2206 2-way Door Speakers
Alpine SPS6939S 3-way Rear Speakers
Nissan Rear Wind/Side Window Deflectors
PIAA Superwhite Headlight Bulbs
Tinted Driver/Passenger Windows
Timing 12 Degrees BTDC

He's already done that.

I thought the reason for the Air Temp Sensor was to help compute the air flow through the Mass Airflow Sensor since it works by passing air cooling a heated filiment.
If the air temp was 32f then the filiment would cool faster then if the air temp was 95f, etc.

Just thought I'd add some confusion to the mix.

You are right in principle. However, the devices are internally temperature compensated (according to information at Delphi\'s site,) such that air temperature does not substantially affect its accuracy.

Also, the response of a MAF is very fast, 15 mS for a 90% flow change.

The temp sensor refered to in this thread is a less responsive device intended to correct for slight changes in combustion rate with incoming ambient air temp, according to what I've been reading.

"Air temperature
When air temperature varies so does burn time of the inducted mixture since it is less dense, again a small map of ignition adjustments graded by air temperature are added to the base timing figures. The engine temperature information is relayed to the EMS (engine management system) by an air temperature sensor located near to the air inlet."

What triggered me into moving the air temp sensor to begin with was after I removed the sound dampening air tube/boxes (most importantly the fender one) I had now doubled the size of the intake to the stock airbox (two intake holes now instead of one). My concern was now I have decreased my air flow past the stock location of the air temp sensor, and might now have to contend with the heat soak from the engine. So I thought if I were to move the sensor out of the hot engine compartment to a location near the air intakes (via the inner fender), the ECU would have a more accurate measurement of the outside temperature. If my temp experiment shows no difference in temp readings, or it's WORSE, another option might be to put the temp sensor back into its stock location, and to insulate the intake tube it sits in. The other intake (where the fender box was connected to) is much shorter in length, so I don't think it would be a problem. Just to let everyone know, I increased my timing to 12 degrees BTDC months BEFORE I attempted these intake/air temp mods.

UPDATE:

Still no knocking/pinging. The weather here has cooled down alot (70s to low 80s)), and the truck still FEELS quicker to me. As for gas mileage, I got my normal 145 miles before I hit the halfway mark on the gas gauge (thats with a couple of days with the AC on).

OK, here's the deal. I've been able to commendeer a temp meter and 3 type "T" calibrated thermocouples (accuracy to +/- 0.1 degrees)from work. I plan on running my air intake temperature experiment this weekend, and I was wondering if anyone had any other areas/parts they wish they knew the temperature of. The real beauty of this is I can now get real time readings with the truck moving (one TC at a time), and under just about any condition. Theses TC's can be put just about anywhere (liquid/solid/surface/air), any requests or ideas?

I think the air intake temp measurements (while moving) would be very helpful to anyone trying to create the best cold air intake. I think the point is that the air intake temp sensor should measure the actual intake temp. (even if it compromised by engine heat soak) I think the EMS works best when the measured intake temp is the actual intake temp.

From reading this post, I think two clarifications need to be made.

1. By moving the sensor are you trying to get a more accurate measurement of outside air, or intake air? (the engine heat soak would also increase intake temps)

2. By getting a different, i.e. lower, intake air temp measurement, what performance gains (timing advance) are accomplished?

Sean,
certainly you could place one thermocouple at the air filter, one at the air temp sensor, and the third at your intake location.

If you get bored you could measure the temp of the trans cooler lines (assuming an auto.)

I was going to suggest the HVAC intake but that's a can of worms.

-paul

Oh man, You mean I reached the end of the thread already. Right when it was getting good.

Good deal. I think putting one in the fender, one in the stock sensor location and one in the intake where you put the plug to cover the hole left when you removed your sound dampening box. What would really be great is if you could talk your job into letting you bring that stuff to GOX. Then we could get Carlton's temps with the snorkel. If his are appreciably lower I would consider contacting TJM for another one.(sold mine)

OK everyone, the temperature test results are in:

After my commute home from work (18 miles), I placed the TC's in the following sites:

#1 New inner fender location of temp sensor
#2 Stock location of temp sensor
#3 Front side of airbox (for engine compartment temp)

http://www.grovestreet.com/jsp/onepic.jsp?id=117311

http://www.grovestreet.com/jsp/onepic.jsp?id=117312

The outside temperature was 75 degrees, and I was parked in the shade. It took me about 15 minutes to hook them up, so I let the truck idle for an additional 10 minutes with NOTHING else running (no AC, no radio). Here are the numbers:

#1 124 degrees and climbing slowly
#2 139 degrees and climbing slowly
#3 146 degrees Steady

I next jumped in the truck and started down the road at about 35 - 40 mph (about 1700 - 2000 rpms). After about 3 minutes the temps were:

#1 76 degrees Steady
#2 79 degrees Steady
#3 83 degrees Steady (as soon as I would stop completly, the temp SHOT up fast)

When you look at the test as a whole, the temperature difference between the stock location and the new location of the air temp sensor is not much. At idle the new location was about 15 degrees cooler, and at idle only about 3 degrees cooler. Is this mod worth it, hard to tell. When moving, I don't know if a 15 degree cooler temperature reading really matters or not. So in retrospect, the perceived increase in performance was probability due to the increased air intake size from my earlier fender sound resonator removal, and not the moving of the air temp sensor. Now that I still have 3 TC's under the hood, anyone want a temperature of something else taken? I have ALL weekend with this setup before I have to return it.

Is that with the thermocouple inside the intake in the stock location or outside the intake? Interesting numbers, I thought the stock sensor would be way off, but it looks like it's numbers were right on when standing still, except for the fender/intake numbers reversed. Weird, does your intake draw air from the engine compartment or the fender well? Can you bring that baby to GOX? I still would like to see what you would come up with if there was a snorkel drawing air from outside of the truck.

I won't be going to GOX (even though I'd love to), too far of a haul for the wife and 2 1/2 yr. As for your questions, #2 is IN the intake, not outside, and both the intakes from the stock airbox take air from the inner fender. I conducted another temp test after dinner (wife thinks I'm nuts ). The TC sites were:

#1 New air temp sensor location
#2 Stock air temp sensor location
#3 Intake after air filter/before intake manifold

Fully warmed up I headed for the closest highway. With an outside air temp of 67 degrees, and traveling at a steady 55 mph (2100 rpms), the results were:

#1 68 degrees
#2 68 degrees
#3 74 degrees

Then when I got home (with dirty looks from the wife, and guess who's not getting any tonight :rolleyes: ), I let it idle for 10 minutes and the temp results were:

#1 115 degrees
#2 126 degrees
#3 120 degrees

And all sites were STILL climbing slowly. All I can say is I'll never get one of those cone filters systems installed in the engine compartment, too much heat soak. I still can't believe how much heat gets into the inner fender well (even after I taped over most of the holes). The good news is as long as your moving, and your intake doesn't take in air from the engine compartment, your air intake temperature after the stock airbox is only about 6 degrees warmer than the outside air.

Sorry to hear you won't be at GOX. I thought I saw your name on the list. Thanks for going the extra mile to get info on here for all of us. I'll be doing a lot more monitoring of my ECU now that I have my scanner installed. I just need to get some days off so I can actually do it.

It certainly explains why the HVAC system picks up so much heat since much of its air comes from the inner fenders.

One though about about why it gets so hot quickly when you are standing - the cooling fan blows hot air over the engine and down towards the cats. As that hot air flows out from under the vehicle one of the natural routes is into the front fender wells. Air that hot will rise rapidly - and it's a short path into the inner fender space.

Perhaps an better intake could be devised via the headlight area, or some path to the area in front of the radiator where the air is much cooler.

Gents,
I've been reading with interest about Sean's various intake modifications. Whether it ultimately works or not, personally I think the attempt is worthwhile. Remember - anytime somebody has the balls to "experiment" like this, we all learn a little bit more about our trucks.

I have a question. Can the Air Temp Senser be damaged in any way or effect engine performance if it is placed in a position that may allow water to contact it?

I ask because I've got a JWT PopCharger installed on my Desert Runner. As many of you already know, the PopCharger does not have a mounting for the ATS, so most folks just leave it in the stock postition on the lower air intake tube. However, I have removed this lower tube (I'm fabricating a heat shield for the PopCharger) and have repositioned the ATS in an area just above and behind the left headlight. My concern is that in this "exposed" position, the ATS might be effected by road spray or rain.

Any thoughts?

TR Graham
TUNFS Member/XOC Visitor
'01 SuperBlack SE Desert Runner w/a lot of mods..

"I didn't say there wasn't drawbacks....."

Mine had dryed mud on it and seemed to work just fine.