Troubleshooting 4g63 gst

[dugan33]

I was hoping someone could explain what exactly happened to my engine. I let my dad borrow my car for ma few days and he broke it. he described sympoms to include: Extreme loss of power, wont get above 2000rpm's in any gear, leak on middle bolt of valve cover gasket, running super rich, stock turbo guage is maxed out aftermarket one reads zero(super weird), and lurching when driving. He drove it to a friends shop and parked it for now. Any ideas of what to look for or what im dealing with would be great.

 

[bryanwheat]

You have a huge boost leak, or a blown out coupler.

 

[pauleyman]

stock turbo guage is maxed out aftermarket one reads zero(super weird

There is your biggest clue. Stock gauge is just a guess. ECU thinks you're in boost so it's adding fuel but it's not making it to the motor. Big leak somewhere.

 

[dugan33]

the leak is what concerns me the most he says he can see a little oil coming out on the middle bolt on valve cover. could it be blown head gasket and valve cover gasket? although he said it wasnt overheating. coupler? do you mean like intercooler or what? im going out there pretty soon. anything i should especially inspect? il post pics once im there. also this is a 1998 gst not a 92 like in my profile pic

 

[Dhan]

the leak is what concerns me the most he says he can see a little oil coming out on the middle bolt on valve cover. could it be blown head gasket and valve cover gasket? although he said it wasnt overheating. coupler? do you mean like intercooler or what? im going out there pretty soon. anything i should especially inspect? il post pics once im there. also this is a 1998 gst not a 92 like in my profile pic

The valve cover bolt leak is pretty common. You can pull it off and re-seat the whole cover with a new gasket and get new hardware as well. This should help cure the seepage.

A blown head gasket has different symptoms than you describe and has nothing to do with a leaky valve cover.

You definitely have what we refer to as a boost leak. The post turbo intake system (which means from the turbo through the intercooler and to the throttle body) is a closed system that needs to be sealed as close to 100% as possible.

If there is a leak, that air is escaping and not making it to the cylinders. The engine computer doesn't know this and is adding fuel for air that has escaped. Anything less than 100% sealed, and the car will not run at top efficiency.

So, you need to do a boost leak test, which means pressurizing the intake system and listening for air leaks, and of course then fixing them.

If the BLT fixes the problem, then you are done. If it doesn't, you can move on to more diagnostics. A BLT should be step one though.

 

[dugan33]

Ok im out at the car right now and saw the issue myself. i can hear click and clack from turbine and its not holding an idle. im going to pull apart the turbo and see whats up. here are some pics and thank you for your help. ya its not head gasket the oil looks fine just a lil dirty and the coolant is green. Sonethings wrong with the turbo but it confuses me that my valve cover bolt decided to leak at the same time also it was blowing super rich out the back.

Well i found issue number 1. there was a snail in my detached intercooler piping. my dad must have bottomed out. it starts and runs now but it developed an exhaust manifold leak amd that valve cover leak. do u think i need a valve cover gasket for sure? what should i clean up and take care of before i drive it again?