blazer antifreeze problems!! help!!

[miss_bhavin03]

I own a 97 blazer 4X4 LT 75,000 miles. having problems with antifreeze leak or burning up. recently have smelled burning antifreeze not on the interior tho only exterior smell. no visable leak under truck but checked antifreeze today and very low. filled to see how long it takes to leak out again. had intake manifold gasket replaced a yr ago so shouldnt be that...thinking maybe heater core? hadnt noticed a problem til winter came and always using heater now. any ideas to what it could be or where it could be coming from?

[TCGrove]

I've had 4 coolant leaks on my 99 Blazer. The heating core was easy enough to smell in the car. The radiator was visible. The intake manifold leaked off the back of the engine and was vaporizing..but dripped when the engine was cool...still hard to find. The one it took months to find was when the radiator cap was bad. It only leaked once the engine was hot and the coolant was vaporizing. I figured it out when the coolant began to condense under the hood. I think I would fill the radiator, get the engine hot, and start looking for leaks. Another item is the overflow/refill bottle. I hope this helps, but small leaks can be a pain. Especially around gaskets. Another thing...you had the intake manifold gasket done you said. Check your oil....no discoloration there????

[old_master]

A cooling system pressure test will reveal where the leak is. If the intake gaskets were replaced with the original style gaskets, it's entirely possible that they are leaking again. Felpro makes an improved gasket, (MS98002T) that if installed correctly, will not leak.

[TCGrove]

Old Master you just jarred my memory on the radiator cap leak. That's why I had a problem finding it. I borrowed a friends test kit (pressure gauge) which of course hooks up to the radiator. I pressure things up to 10-12 psi and didn't find a thing because it was the radiator cap itself leaking. The test kit was great for finding my intake gasket leak too.

[Jerry80871852]

Originally Posted by old_master

A cooling system pressure test will reveal where the leak is. If the intake gaskets were replaced with the original style gaskets, it's entirely possible that they are leaking again. Felpro makes an improved gasket, (MS98002T) that if installed correctly, will not leak.

Question Oldmaster.

I think recall that a Chevy house mechanic told me to be thankful I had a 92 S-10 when he replace the fuel line under the intake that hooks to the injector assembly that later model S-10's had a problem with intake gaskets leaking, I'm thinking he stated they changed the make up of the gasket and they were prone to leaking.

Would that be what your referring to.

Yet it seem to me every model has its own little problem that will show its ugly head from time to time.

[old_master]

TCGrove,
The pressure tester comes with an adapter for checking the cap. I usually check the cap first for the very reason you stated!


Jerry,
Up to and including 1995, 4.3L Vortecs use the CMFI fuel delivery system. Fuel leaks inside the plenum are very common. 1996 and newer use the CSFI fuel delivery system which is totally different. They can also develop fuel leaks inside the plenum, but they're rare. Usually the poppet nozzles will get clogged. Intake gaskets on the two engines are different and the Felpro improved design is only used on 1996 and newer engines. You're right about each vehicle having its own set of unique problems.