I am not really sure if this should be in Performance bt here goes. When the truck is cold from sitting all nite, I smell a coolant like odor coming from the vents. I had this same type of odor in the 2000 truck I had, also with the 5.3l motor. The smell goes away in a few minutes after warming up. I know I do not have a heater core problem and do not see any leaks in the system The 2000 truck I traded in was more noticeable in the intensity of this smell. It seems to be more prevelant when it is below 60 degrees at night or it has been cool and raining. Anyone else have this experience?

 

I guess I'm alone in this situation huh?

 

Maybe when you shut the motor off the coolant boils into the overflow. If your coolant does boil back up you will smell it. Watch when you shut it down to see what happens. Its just a guess.

 

shutting the engine off woulnd't have anything to do with when he starts the truck back up in the morning.

 

This is just an od thing. The 2000 I had did this and now the 2002 does the same thing. It would be peace of mind I guess if this is happening to others. It does not seem to be affecting the performance in any way. Thanks for the feedback, its really cool having this site to find info.

 

Are you sure it's a coolant odor? It may be a mildew smell from the fungi growing on the evap core. Just a thought.

 

I had the same problem. Smell, but no noticable leak. Well finally, it reared its head and did turn out to be the radiator. It had a pin hole leak that finally after leaking enough left a trail.

 

I too know the mildew like smell, and this is different. I saw some posts lately about the mildew and I do the same thing to get rid of it. Crank the heat for a fex minutes and use all the vents to burn up and kill the evil mildew. The coolant smell does go away too, but is smells alot differnt. Thanks.

 

The 2000 I had was pressure tested two times by the dealer, and those guys said all is well??? Who knows.

 

I believe there are some kind of vents that create the smell. I know what you are talking about. It's not as bad as a heater core thing, but once in a while I smell it too. I don't remember where the vents are, but I believe they are for eliminating air lock or something. I could be wrong, but it sounds good