Lots of BlowBy and Over heating when Idle

[Keith Gauthier]

I recently dropped a motor in my 1992 6.2, the motor that I put in is a 1990 so I put the newer Intake Manifold and injector pump, brand new water pump,thermostate,intake gaskets. When I looked at the old gaskets I noticed that one of the exhaust ports were closed off, but with the new gasket set all the ports were open, will this have any effect on blow by or the cooling problem that Im having :confused:

Thank You Keith

[john8662]

The port in the intake manifold gasket is for EGR. If you don't have an EGR intake manifold, you'll want to get the non-egr gasket that has the block-off on it.

Not to fear though, using the gasket with the port open on it won't cause any issues. I prefer (just a preference) to get the 80's J-series intake gasket (heavy duty 6.2) that gives you the corret intake gasket with the metal block-off plates on it.

Overheating, since you have a new thermostat, this might be a place to look, as it might be faulty.

As far the blow-by, ensure you're looking for blow-by with the airclearer installed with an air filter (system has to be complete). This is so that the engine will pull it's sufficient vacuum to eat the normal amount of blow-by. Blow-by above and beyond what is normal will start to appear with the oil fill cap removed and a running engine.

The gasket situation mentioned also isn't your source of blow-by.

[Keith Gauthier]

OK, I replaced the thermostat and it still has alot of pressure at the radiator cap enough to spill into the over flow, when idling I had the cap off and it seems to have bubbling issues. As far as the blow by it's coming out of dip stick tube Thanks for the quik respons

Keith

[john8662]

Used engine for transplant?

Sounds like you have a head gasket issue on this engine, probably the reason it's running hot on you too.

Your best course of action here is going to be to get a compression tester and see what cylinder is leaking. That will let you know where the problem is, and where to look for problems, and if you can see the gasket has failed you will know that you'll fix the problem with a new gasket.

If you end up taking the heads off, you can look at the cylinder bores and see the condition of the engine. From the sounds of the blow-by, it's not good.

J