I bought a 03 Xterra with 33000 miles on the clock a month ago. And I swear I can smell some coolant after I shut the car down. It is not the strongest smell but it is there especially around the radiator and overflow. I have changed out the radiator cap and it is still there. There are no puddles under the car and I have been keeping my eye on the level of the over flow but since I have been on vacation the past 2 weeks I have been unable to tell if it is getting lower or not (I did top it off when I got the car). I brought it into the dealership this afternoon for something else and had them pressure test it and there are no leaks. But I do not know how much faith I have in the dealer as of yet .What else could it be. A bad gasket? The guy at the service desk told me just to keep my eye on the level. And give a call back if it is getting any lower. Maybe it is just my OCD but I swear I can smell coolant. I do have the extended warranty ( I am a sucker I know). so if it is a major problem hopefull that covers it.

Is there anything I should be looking for. And when is it best to check the level in the overflow warm or cold.

Thanks for the help

Matt

I have the same problem in my 02 with 62,000 miles. Dunno what it is though. I fear headgasket seepage.

My 00 with 64k has a tiny leak I believe in the head gasket on the drivers side, but I can't see exactly where and it's very slow. Over the last month or two that I've smelled it, the level has never fallen. Still planning on putting some leak stop in it.

Does leak stop really work and are there any adverse effects to using it

Yes, I used Bars Leak (brand) on a leaking head gasket on an Explorer. It held for 100K miles.

If you do use leak-stop, then be very careful if you're going to need all of your cooling capability (e.g. high temps at high altitude).

ed

I do not think I am going to use the stop leak from doing some searches on it I am not too sure I want to go that route. I need to bring my truck back to the dealer next week when they get my new seatbelt in. I am going to have them check it again . Would the pressure test have found a leaky gasket?. And I was reading the work order from the dealer and it said that the customer smelled coolant inside where as I told them outside.
And I am sure they did not have the truck running long enough to produce the smell.
Basically I am going to keep going back to them until they fix it.

A coolant system pressure check ought to reveal something.

ed

i just had my 02 in for the exact same thing. I smelled coolant in the truck as well as when i pop the hood. I have smelled it since the day i bought it 30k miles ago. NOt one drop of fluid has hit the ground and the coolant has not changed level at all but i still smell it. I had them pressure test the truck and they found nothing. maybe its just an x thing. OR we are all busted or something...lol

I had the same problem with my X recently, and it was a bad o-ring on my throttlebody of all places. The leak started around 58,000 miles, and I usually didn't see coolant on the ground because it would find it's way to the exhaust manifold.

Check the bottom, back side of your throttlebody for this particular leak. The component is called a thermo element, and it adjusts your high idle. It is also commonly referred to as a wax pellet. The fix is cheap and easy, you only need to replace a single o-ring. The hardest part was removing an overtightened screw on the throttle body.

For more information, search wax pellet or thermo element. Also, I have also read on this board about difficult to find leaks from a head gasket, towards the front of the engine. Good luck.

Everybody thanks for the info. I have been keeping my eye on the coolant leak this week and so far I have not lost any. As soon as the snow melts here I am going to check out the wax pellet I will just do a search on here and find out where it is located. When I do smell the coolant it is coming from the front of the engine compartment but the did a pressure test so the radiator is fine. Maybe it is my overflow bottle or one of the other areas mentioned or then again it could be just me . One of these days I am going to get somebody else to besides the dealer who knows a thing or two about cars unlike my self to check it out also

Thanks again

Matt

Well found out the problem of my leak was actually the water pump. The coolant I saw on top must have been blown up there by the fan. So getting that taken care of, plus the timing belt, and the other 3 belts, and flush cooling system for a tad under $500. Only 64k miles on my 2000 but it's the only real problem I've had with it with the exception of a cracked exhaust manifold covered under warranty. Thanks for the help guys.

The spring-tension hose clamps that come on the truck kinda suck... I've had problems with coolant smell from tiny leaks from the upper radiator hose connections.

It wouldn't hurt to replace them with the screw type clamps - it's cheap and will rule out a possibility. Change the ones on your power steering hoses, too - those will eventually start leaking.

My 2000 Xterra had a constant coolant smell when warm. Ended up being a very small leak where the thermostat mounts in the intake. You could see green crusty dried coolant around it. Never bothered fixing it and the truck got totalled anyway.

My 2002 is leaking from the fast idle thermo element (wax pellet). I drove it last on Monday and parked it the rest of the week (I'm driving my VW to save on gas). Since then, a small wet spot, about 8 inches in diameter, has appeared under the truck. You can usually see a couple of drops of coolant just back of the front skid plate on the crossmember at any time.

I have an 02 with 65,000 miles and have noticed a small coolant leak myself. I have yet to see a puddle or anything under the truck, i think it only leaks when its running and heated up, but then again I dont know much about the whole radiator/coolant thing since I'm a newb. Right now, it takes about a month or two to go from the full level down to the low level. Do you guys think its anything to worry about? Or should I just keep filling it up until it really starts to leak on me?

Well it looks like mine is also leaking from a couple other spots also. Mechanic said after he took the water pump off he could see a couple other places that had small leaks where Nissan doesn't use gasket, just RTV so that's being taken care of also.

THE THERMO ELEMENT ! ! !

My 2002 is leaking coolant from the thermo element an I have to replace the throttle body. I talked to the dealer and the service mngr. said that he's experienced this problem on several client's vehicles.

I donno, but it sounds like a design defect to me.

If you're halfway handy with a wrench, you can fix the thermo element with a $1 O-Ring from the auto parts store.

x2

Technically you don't even need to be handy with a wrench. There is only one overtightened screw between you and that o-ring. I was quoted $300 to fix the leak. Instead I fixed it for free using an o-ring from work.

I'm not very experienced with doing work on engines yet, where is the thermo element located? Anyone have a picture?