Hi Everyone- I have been smelling coolant when I turn off my 95 K1500. It seems to be running fine and the coolant level isn't going down any. This has been going on for a while now. I asked my mechanic at one point if I needed a new radiator, and he told me I didn't. What else could be causing this odor?

Thanks!

 

You must have a very slight coolant leak that is just enough seepage to give you the smell without noticing a drop in the level. A common spot is the intake gasket and if it is leaking in the rear you will never see the leak, but just smell it burning off the hot engine. Have your mechanic pressurize the system and look for the leak. If you are smelling it, it is definitely leaking somewhere.

 

Ok, that makes a lot of sense. I've never seen a leak. Is it hurting anything to let it go as it is? Or should I definitely get the pressure testing done? If its leaking does the radiator need to be replaced?

Thanks so much for your help!

 

I can't say for sure where it is leaking from here, but yes I would definitely get it pressure checked. It doesn't necessarily mean the radiator is leaking though. If it is an intake gasket I would do it sooner than later because they can start to leak internally and that is very bad for bearings and cylinder walls. In the mean time keep a close look at your oil to make sure there isn't any coolant in it. It will start looking milky (like chocolate milk) if there is. Also check the cap where you put the oil in at to see if it has a milky build-up there. They "usually" leak to the outside and with you reporting that you smell it that is at least part of the case for you, but there is still the possibility of an internal leak as well.

It could definitely be something else though. Another real common spot on these is the heater hose that goes to the back of the intake. The adapter that threads into the intake is known to corrode and leak. Most just replace it with a nipple and a regular length of heater hose.

 

I had a bad intake manifold gasket on my Tahoe that produced symptoms when the engine was cold of an overly rich fuel mixture. I took it to two dealers' service shops and two independent garages and none could diagnose the problem. Once the coolant level started to drop I knew what the problem was an ordered a top quality after market gasket set for the truck and had a local garage install them.

I was lucky that no damage had been done to the engine as coolant that gets past the cylinders and into the crankcase can do severe damage to the engine. I would strongly recommend buying after market gaskets and not using the GM ones.

 

I had a 96 5L V-8. Replaced intake gaskets@ 65K miles using OEM parts. Then again @ 130K miles using Felpro parts. The parts guy showed me the blurb about how they specifically addressed the problem. They use steel instead of plastic to frame the seals around the ports. The plastic is pushed out by the pressure and will leak like a faucet. The seals around the intake ports will also start to leak. Be sure to use the correct thread sealer on all eight intake manifold bolts, and follow the bolt torquing sequence.