If I have a intake gasket leak, nothing showing outside, but it seems theremaybe a bit much exhuast condesation, well when the truck cools is it possible there's air getting in the cooling system? Causing me all the grief bleeding the system so often? It does't smell like coolant really from the exhuast or sweet, just wondering if maybe it's the intake gasket gasket leaking internally, I can't find any leaks around the intake itself, hate to tare it down for nothing, anyone ?

 

Do you know if the intake gaskets have ever been changed? If they haven't I'd say there's a good chance you have a leak. Coolant going into the motor is never good, it can wash the oil off of critical engine parts and ruin your motor. Give the lower manifold area another good look and see what you can find. If that turns up nothing then you might try a cooling system leak down test.

 

You can do a cooling system pressure test by applying a set pressure (do not exceed 16psi) to the cooling system and monitoring it over time. This will confirm/deny the presence of a leak.

 

By doing this pressure test, can I just do it myself by maybe pulling the 1/2" plug on the intake next to the t -stat?Or do the rent the testers if you know ?If I do this myself, you say monitor the pressure over time. Give me an example, how long it should hold pressure for. I read some of your threads back in 05-06 when you did your Bravada, Was it as easy as it looks?, any surprises? Last thing, is there anyway I could pick-up something to see if done visually in the past? Thanks in advance & Happy Holidays !

 

It should hold 16psi for a good long time. What you will be looking for is a steady drop in pressure which would indicate a leak. You can get a pressure tester that replaces the radiator cap.

Are you referring to when I replaced the intake manifold gaskets on my Bravada? If so, search for "D-tips" as there is a very detailed article posted on D-tips.com showing the replacement of the intake manifold gaskets on the SCFI motor.

 

Okay, Then listen to this, when being driven normally, We come home I checked the pressure in the hose it's like a rock, BUT only after a short 15/20 mins It seems there's hardly ANY psi there, A safe bet to say there's a leak?

 

It does not take long for the temperature of the motor to cool down enough to relieve the pressure. The only reason there is pressure in the system is because the coolant expanded and the radiator cap held to its specified value. The reason for the pressure is to increase the boiling point of the coolant.

With a cooling system pressure tester, you manually apply the pressure with a hand pump (normally). I would do this with the engine cool so you do not get any effects from the cooling of the engine/coolant during your test.

 

I totally understand that, it seems to its awefully quick to lose pressure that fast, But I'll see about renting a tester. Thanks