SR20DET Bad Headgasket? Something else?

[KiLLeR2001]

I'm not too sure as to what exactly is going on with my engine, but if I had to take an educated guess I'd say my headgasket is failing. SR20DET redtop, all stock specs with only about 10,000 miles since the rebuild...

I'm getting pressure in my system and oil in my radiator... When I rev the engine with the radiator cap off, the water will shoot out of the radiator. My car however DOES NOT overheat at all. I also am not smoking out the exhaust pipe either. There is a leak out of the front main seal, I'm guessing due to the pressure going everywhere. Car seems to run great up until around 4500 rpm, then the power just tapers off drastically. No idling issues at all either.

When I shut my car off, one of my heater hoses on the intake side of my engine will start to leak water out until all the pressure is relieved. When the car is running however, there is no coolant leak at all. Usually when I go to take off the radiator cap after 5 minutes, theres no pressure left.

I've talked to a few people and they've told me it could be a few things, but has anyone had very similar experiences and can pinpoint the exact problem? I'm going with leaky headgasket but I dread it be something more internal.

:aw:

[KiLLeR2001]

Just did a compression test on the engine... 160-160-160-160... Could this be turbo related and not the hg?

[94eghatch]

could be a turbo related problem, check the center of the turbo, may have a blockage in the coolant system somewhere though.

[KiLLeR2001]

Not sure if this is related to anything or not, but if I rev my engine in neutral, the turbo will never spool up, only way it ever spools is under load.

[KiLLeR2001]

Need some input guys. Don't want to start tearing things off my car if I'm not even sure what the problem is.

[slider2828]

Headgasket.... done and done....

Damn what is wrong with you car... its demonic man....

Anyways, head wasn't torque right or you have a crappy headgasket. Get Apexi next time...

[slider2828]

if its turbo blockage.... its going to be hard to find and rare.... Leak down test will tell you exaclty where you problem is as well..

[KiLLeR2001]

Despite my even compression test across all 4 cylinders you still think its the headgasket?

edit: I'm really starting to lean towards my turbo because awhile back my car would periodically smoke out the tailpipe during idle only. However, it does not do it anymore...

[KiLLeR2001]

A few more tidbits of information...

When I'm in higher RPM with turbo spooling, my water temp needle will dip down lower. It will eventually climb back up to normal operating temp.

Another thing I noticed today is where the exhaust bolts up onto the engine, it looks wet of oil around the base..

Here's a picture of what I'm trying to explain...

http://tehl33tsite.com/240sxdd/help/IMAG0005.jpg

[SoguRacing]

i think your temp needle drops because you have air in the system. as for oil in the coolant...and a compression reading of 160 I don't know what to say. That's very odd.

[dori_sil8t]

it looks like your valve cover gasket it leaking oil onto ur manifold. which will cuz a fire sooner or later. id say do a cyl leak down test and go from there.

[KiLLeR2001]

There's no trail of oil from the valve cover gasket to the exhaust manifold, it looks oily around there because my front main seal is slinging oil everywhere around my engine bay (to the hood dropping down onto the valve cover)

[Monooxide]

The HG can fail and still yield good compression numbers. The HGs main job is of course to seal off the combustion chambers but also remember that it divides off the oil galleys and coolant passages from the block to the head. If one of those were to not seal from coolant passage to oil galley this would give you the exact issue.

Be sure coolant isn't getting into your oil as this can damage bearings. Also, if there isn't coolant in the oil really this would point even more to the above mentioned problem because the Oil Pressure will be higher than the coolant therefore the oil will flow from the oil galley to the coolant passage and the coolant wouldn't be able to flow into the oil galley.

Good luck.

[KiLLeR2001]

The HG can fail and still yield good compression numbers. The HGs main job is of course to seal off the combustion chambers but also remember that it divides off the oil galleys and coolant passages from the block to the head. If one of those were to not seal from coolant passage to oil galley this would give you the exact issue.

Be sure coolant isn't getting into your oil as this can damage bearings. Also, if there isn't coolant in the oil really this would point even more to the above mentioned problem because the Oil Pressure will be higher than the coolant therefore the oil will flow from the oil galley to the coolant passage and the coolant wouldn't be able to flow into the oil galley.

Good luck.

Thanks for the reply. I will drain my oil and see if it has any coolant or looks milky in anyway.

Let's say the oil is fine. Are you still going with a bad HG? Are you able to rule out that it's a bad turbo?

[initial_drifter]

In most cases, if not all, a radiator with water gushing out is due to a Faulty HG

I'd recommend parking it ASAP and tear the motor apart to check for damage.