I was driving going a little over 80mph in full boost (7psi) and heard a very soft "poom" and a drastic reduction in power. The boost gauge went way down and i let off the throttle. Vac didnt go to 18-20 like normal and only went to 10. I then drove another mile and the car seemed to correct itself somewhat but still was a lot weaker and the motor was clicking loudly and bucking a little. This all indicates to me that there is a blown piston.

I then pulled over and let the car idle and the rpms were jumping from 300-1300 roughly. The clikcing continued and we watched as the motor shook in the motor bay. We then pulled off each of the plug wires one by one to see if it changed but it didnt. We couldnt pull off the coil packs to check the other two tho since we didnt have any of our tools with us so assumed it was most liekly one of the other two pistons. Then there was this huge 4hour ordeal where there was a big mess getting a tow truck to tow my car from that town to my town, but i wont get into that. Today we pulled out each of the spark plugs to see if the spark plugs had any oil or any sign of detonation and there was none. So we went to autozone to rent a compression tester, but they dont rent them out. So my friend is bringing me his tomo or the next day. Im hoping there is a different problem that is easier to fix bc i dread the thought of having to take everything apart to replace one piston.

Can you guys think of anything else i should check? I saw no signs of any leaking fuel or oil anywhere. If it is the piston i think ill probably just have to replace the whole motor bc one of the bolts from the oil pan broke off in the hole and i believe that it goes thru the oil pan to the bottom end. I tried tapping it months ago and so did a local shop but neither of us could get it out. So if i cant get teh oil pan off, then i cant get teh pistons replaced. Any thoughts?

 

IC hose?

 

no intercooler

 

get a compression tester, that's the most sure way of knowing. You can rent one from most car-parts places, or if you know someone with a shop I'm sure they'd let you borrow it. measure all the cylinders, the one that's way lower or none at all is your culprit.

 

If anything, you can get used motors from EBay for $300 no kidding....there was a couple a few weeks ago.

 

i guess you didnt read it all

 

yeah i know, thats what im thining i have to do if i cant get teh oil pan off, shouldnt be too too expensive (relatively), but still is going to be a lot of time and work.

 

How is the bolt in the oil pan broke? Is it just the head thats snapped? If so, you should be able to get it off...any pics?

 

nah sorry i dont have pics, i dont have a digi camera. i have a pda camera but the resolution is pretty bad and probably wouldnt show up.

its not just the head that is snapped off, its the the head and the bottom half of the bolt (pov when it is screwed up into motor)

 

If the oil isnt leaking, then dont worry about it. It shouldnt hurt. Why wouldnt you be able to get the pan off? If anything, Im almost sure a machine shop can do it when the block is out of the car.

 

yeah they should be able to do it but i dont want other ppl doing my stuff. im not worried about oil leaking, i have to check it again but i think that the bolt is connected to the threads in the oil pan and bottom end so i wouldnt be able to get the oil pan off. i need to check it again bc its late and im tired and dont remember what it looks like in the hole.

 

I took my pan off myself, anf I dont remember seeing any bolts that use the oil pan to thread into. All of the threads are in the block from what I remember. I could be wrong though.....I would say 90% sure no bolts are threaded in the pan itself....

 

use an easy-out to get the rest of the bolt out. and damn...another RRM turbo car blowin a motor...whats the deal with that

 

mike that sux man...hope ya fix it soon

 

Yeah Mike, keep me informed as well please. I am not 100% convinced that you blew a piston (or is it that I am trying to not accept the fact tht you did, cuz that would just plain suck) but I hope you figure it out soon. When you were driving, was the car smoking or anything? Hopefully, it is something minor, like your MAS could not handle the limits of boost and that was the thing to go. Does the G94 have a knock sensor? Any CE light?

I had a similar problem with my G93, but it was more severe in terms of, I was dropping two cylinders (or so it seemed) and it turned out to be a bad MAS which in turn caused my CAS to go haywire.