Blown turbo? bottom end? Head hasket? Please Help!!!

[hollywood_ikr]

I was getting on the freeway on saturday night, and I floored it at 16 lbs of boost... I was only an exit away and since I was on the off ramp, I let the car coast on neutral to the stop light. Then my car felt really bad like if it was heavily misfiring or something similar I was barely able to park the car in the gas station next to me. Since it was late I had the car towed to my house.

When I turn the car on it idles near 0 and it is EXTREMELY rough not drivable at all. When I accelerate to stop it from dying it won't do much, if I accelerate more it spikes to about 4k and I hear what appears to be a backfire. One other thing... for about a week when I would accelerate hard in neutral I could hear like a faint rattle or what I thought was something in the turbo grazing the walls.

I have used the search and I have checked the oil and it is NOT milky looking and the coolant has NO oil in it. I visually inspected the piping and there were no obvious boost leaks, (I imagine a problem this big would have to have a large boost leak if it was one) Then I thought it was a blown turbo for sure but the damn thing appears to be intact when I took off the intake there was no shaft play and it spins smooth as far as I can see!

Can anyone help?!! What's wrong with my beloved gst?

My mods on my profile are up to date if you would like to see what I am running.

 

[92AWDHX40]

Did you do a compression test.

 

[hollywood_ikr]

Did you do a compression test.

Not yet, I don't have the tools for that. I'm trying to troubleshoot the best I can without going to a mechanic. For the time being can lets just say the compression is good (which I really think will be the case)... My engine is meticulously maintained with only mobil 1 synthetic and is extemely reliable I don't think it's bad compression.

Is there anything else I can check before a compression test is absolutely required?

 

[ShawnsGarage]

Not yet, I don't have the tools for that. I'm trying to troubleshoot the best I can without going to a mechanic. For the time being can lets just say the compression is good (which I really think will be the case)... My engine is meticulously maintained with only mobil 1 synthetic and is extemely reliable I don't think it's bad compression.

Is there anything else I can check before a compression test is absolutely required?

Most auto parts store have the loan a tool. Go rent a compression tester and post the results

Have a friend stand behind the car and watch for smoke and if it smoke what color.

 

[bluegs03]

Yes do a visual inspection of the intercooler piping, see if one has blown off. Then do a boost leak test, if anything those will help you when you fix the problem if not solve this one.

Is there anything else I can check before a compression test is absolutely required?

 

[crimsondragon]

Definitely sounds like a boost leak.

 

[weegee5029]

Check the timing, that's the only other thing it can be

 

[ShawnsGarage]

Check the timing, that's the only other thing it can be

 

[hollywood_ikr]

Most auto parts store have the loan a tool. Go rent a compression tester and post the results

Have a friend stand behind the car and watch for smoke and if it smoke what color.

I was about to doa compression test and since it is recommended to change the spark plugs when doing a compression test, I replaced them, my oil catch can, and unplugged the battery in case there was a malfunction with the eprom. I also did a very thorough check of all my piping and it looks completely solid no issues there.

I said what the hell so I fired it up and it idled perfect! Everything seemed in great working condition. I go inside to wash my hands and call it a day, and I faintly hear the engine missing so I run out there and the same problem is still occuring once the engine had warmed up!

I disconnected the battery again to see if the eprom was the problem but the misfiring resurfaced immediately this time.

Do these symptoms mean anything to anyone?!!!

I will do a compression test now....

 

[No_Skillz]

I was about to doa compression test and since it is recommended to change the spark plugs when doing a compression test, I replaced them, my oil catch can, and unplugged the battery in case there was a malfunction with the eprom. I also did a very thorough check of all my piping and it looks completely solid no issues there.

I said what the hell so I fired it up and it idled perfect! Everything seemed in great working condition. I go inside to wash my hands and call it a day, and I faintly hear the engine missing so I run out there and the same problem is still occuring once the engine had warmed up!

I disconnected the battery again to see if the eprom was the problem but the misfiring resurfaced immediately this time.

Do these symptoms mean anything to anyone?!!!

I will do a compression test now....

BLT. You can't look at a coupler and decide that it's not leaking.

 

[gorf]

Definitely sounds like a boost leak.

+2
if you have the stock ic hose you probably blew it off or popped a hole

 

[hollywood_ikr]

As was suggested I rented the compression tester at Auto Zone...

I just attempted my first compression test and here is what I did..


1. I pulled the mpi ("engine" )blue fuse

2. I disconnected the triangular coil connector

3. I screwed the compression gauge into the cylinder

4. Had a friend crank the engine for about 10 seconds at WOT


Results for ALL 4 cylinders was about 20 psi!!!! WTF?!!!

I also Did a "wet test" and it made no difference whatsoever.

Did I do something wrong could my engine be that messed up?!!! On all 4 cylinders though????!!!!! Could it be the gauge...

But also keep in mind that I just turned on my engine an hour ago and for 5 minutes it ran perfect...

 

[SD99GST]

No way compression could be that low, I would check to make sure you screwed in the tool correctly, listen for leaks on the tool, if nothing helps, go to another Auto Zone and try a different one.

The needle should go up in steps, on the compression gauge, then top out. But I really have never heard anyone having psi so low. Is it 20 across? has to be a faulty tool.

 

[SD99GST]

By the way, make sure you have WOT when doing the compression test. I forgot first time I did one and it will raise compression quite a bit.

 

[hollywood_ikr]

No way compression could be that low, I would check to make sure you screwed in the tool correctly, listen for leaks on the tool, if nothing helps, go to another Auto Zone and try a different one.

The needle should go up in steps, on the compression gauge, then top out. But I really have never heard anyone having psi so low. Is it 20 across? has to be a faulty tool.

You were right it was the damn Autozone gauge, weird because it looked brand new.

The compression results are...

163, 160, 151, 155


I also checked the DSM Link and the codes are:


0300 Random Misfire detected
0135 02 sensor heater Circuit Malfunction (front)