Thread: Smelling coolant

Check the Plastic coolant elbows on the alternator bracket. They get brittle and leak with age. Pretty common on the 3.8's

Besides the elbows, I'd also check both rad hoses and the heater hoses if they are older. Only takes a little seep to cause a smell. Also give the radiator a look and see if there is a trail of dried up coolant on the side tanks or on the fins.

Yes, the radiator, especially the cap. I got a Chevy venture for free that I was told had a bad head gasket. It ended up just being the cap was worn out, after I replaced that, the coolant level didn't move.

An no, the headgaskets on these engines rarely ever go bad, even if overheated. Usually it's the elbow(s) that will leak first, followed by the rad. A lot of times the rad. will leak when hot and under pressure then stop when it cools down. My 00 GT did this for about 4 months before I finally tracked it down to a bad drivers side tank seal that was right under the rad. hose.

Hopefully you get through the bitter cold w/o whatever is leaking completely failing. Another thought would be to pick a warm~ish day and with a cold engine degrease the crap out of it and hose it clean. This would be a good place to start so you know you're not smelling something from a long time ago.

It could be the lower intake manifold gaskets. As mentioned, it's rare for the head gaskets to fail on these engines. If the lower intake gaskets are leaking, you may have a bit of coolant pooling up in the area where the manifold bolts to the head. Look around the fuel injectors and you may find the coolant smell.

Years ago I remember being able to smell coolant and found a very small amount leaking behind the supercharger because the LIM gasket failed.

The updated GM gaskets are metal. Part no. 89017825

Originally Posted by FordMan77

Usually it's the elbow(s) that will leak first, followed by the rad. A lot of times the rad. will leak when hot and under pressure then stop when it cools down.

Thanks. Am I right about the elbow being the sharp plastic piece at the front of the s/c? Others?

(Yes, the cold season is the deterant, LOL)

Originally Posted by GTP Mark

It could be the lower intake manifold gaskets.

I didn't think s/c models had LIM. Embarrassing. Thanks for the part number.

I better do some better searching.

I sort of had the same problem. My car would overheat thru the top of the overflow bottle and since I changed the rad cap it has been fine....

I  sort of had the same problem. My car would overheat thru the top of the overflow bottle and since I changed the rad cap it has been fine... 5.3L GXP

Thanks for all the suggestions. I am going to be on the look out for these. For the time being, in bring this down to DEFCON 2.