Pressure in Coolant System?

[cookmeup272]

Ok so I don't know if im paranoid or not but I'll let you guys know what going on. It seems to me like my coolant hose gets wayyyy to hard. Brand new headgasket with ARP Headstuds. New radiator cap. I never get past half, hell I barely even get to half. The one thing I can think of is it seems like i have a very very very small leak at my water pipe where it pops into the waterpump. The O ring probably needs to be changed. Could air be being sucked in and overpressureize the system? Or does your upper hose get pretty hard?

 

[1992awdlaser]

The thing to do is:

1. Let the car cool down completely (over night)
2. Remove radiator cap to release any pressure that may be in the system (not likely after step 1)
3. Put radiator cap back on
4. Start the car
5. Carefully take the radiator cap off after one or two minutes of it idling
6. Don't let the car warm up at all really as this will build pressure in the system
7. If your system is getting pressurized, it should release pressure when you remove the cap


If you don't want to wait to let the car cool down you can just remove the cap to release the pressure and then re-install the cap. Then take the cap off after a few (10-30) seconds.



If this shows pressure your headgasket is not sealing.

 

[cookmeup272]

I have also ran the car with no radiator cap. It might just be normal like I said but I am kind of paranoid. A buddy of mine with a 2g NT says his gets like that as well but I take that with a grain of salt.

 

[1992awdlaser]

Another thing you can do is let the car run without the cap on and look at the coolant to see if you notice bubbles coming out.

 

[cookmeup272]

ill have to do that....I know the thermostat is opening because last time I ran the car with no cap, I could see coolant flowing. My car NEVER overheats. And both of my hoses feel warm.

 

[boostforfun]

I know you have a new head gasket, but a quick leakdown test will make sure it is sealed. Just do the leakdown and leave the radiator cap off. If you see bubbles, then HG is not sealing.

 

[TenSecondSTi]

I know you have a new head gasket, but a quick leakdown test will make sure it is sealed. Just do the leakdown and leave the radiator cap off. If you see bubbles, then HG is not sealing.

A leak down test is to check for a bad valve seat or bent valve. If it leaks and you add oil then doesn't one or all of the valves aren't sealing. Also dont forget each cylinder need's to be at TDC for this test and I usually go up to 90psi. I suppose you could take it to 145-160psi witch is the pressure these engines see without boost during a normal compression test but better safe then sorry.

If you took the cams out during the test and held the crank with a breaker bar you could rotate the engine to see if the cylinder walls are egged out. Or if the rings are leaking also for future knowledge.

Somewhat the leak down test could tell you if the head gasket isn't sealed. But if this was his case I'm sure his plugs would be glazed and he would see antifreeze on top of the pistons Also it would be blowing white smoke the whole time while running. It would also add pressure to the coolant system under boost and most likely bust a coolant hose. Or find the systems weakest link.

I think your thermostat is bad. (Sticking) but not sticking bad enough to make it over heat just to add extra pressure in the system. I had this happen to me on a new one none OEM, Now it's stuck open and won't build pressure heat is weak. And coolant temp drops to 160s while driving. I'm changing it tomorrow.

 

[EclipticalGS]

my coolant temp. gets to half way and stays there, Heater blows hot, and my upper radiator hose looks like a buldging sausage. I am using a 15psi rad cap from Autozone and I havent seen any coolant escape it yet.

Those O-rings are notrious for leaking man, just replace the bi***, and put a dab of spit on the end before you squish it in the waterpump inlet.

 

[firefighter]

You don't have to do a leak down test. What you need to do is a coolant system test. What you will do is pressurize the cooling system. The pressure kit has a guage on it. Apply pressure to it if a leak is present the system will not hold pressure. A lot of times if the HG is bad you will end up with coolant in the oil.