Car is an my02, 68k miles and 4k boosted with a FR Gt35r setup. Motor had low compression on Cyl #4 (180, 180, 180, 150) It wasn't super low so we thought the HG was on its way out. Car was also experiencing low to no heat at idle (stationary) but heat while moving. Rad also wasn't pulling coolant from the overflow back into the system..

After pulling the head off, we found the 4th cyl had some decent scoring and some pretty heavy gouges. He pulled the rest of the motor apart last week and the 4th cyl piston also had some nice skirt damage but the rings were all intact. All the other cylinders, the rings were all damaged.





3mm HG had about 4k miles at 580whp. Car only saw 93oct but from what I've been told this could have been from a bad tank of gas.

 

I've seen plenty of cracked rings from detonation.

 

This is why I completely stay away from pump piss and at least run a higher 110 octane cheap race gas all the time.

 

YIKES!!! w/ those coolant issues, my guess it that ur HG was done for as well.

what did cyl #4's rod bearing look like? u may have spun it... our engines especially my02 and earlier have always been prone to what seems to be cyl 4 oil starvation issues for some reason??? also, the other 3 cylinder's rings being damaged might have caused enough loss in oil pressure to eventually spin cyl #4's bearing....

i blew a headgasket, then eventually spun cylinders 1 and 4... LAME!

 

how does the piston ring problem effect the rad not pulling coolant back from the overflow tank? that sounds like a rad cap problem?

also what do you mean by no heat? no hot air from the hvac system inside the car? or do you mean coolant temps were low at idle and high while moving? still seems kind of normal with more load on the engine at speed.

i know you know your ish, just curious for a little better explanation.

good luck with the rebuild! are you going to use all oem stuff? or go with an overbore/new pistons?

 

Jeff, who's car is this, PM me you want to keep it private, thanks

 

i would say that bad gas is a definate posibility tho, its sucks to see ;(

 

almost makes me want to get tuned on 91, then just buy 93............. don't know if it would make much a differance

 

it sounds like it could have been his car....580ish whp with a 3mmHG

EDIT: nvmind he doesn't have a FR setup.

 

He was referring to the coolant overflow and no heat at idle as part of the headgasket diagnosis. A faulty cap could cause the overflow to not work properly but in this case it was the headgasket. Air pockets develop (from combustion chamber) in the coolant system (heater core) and it will actually blow ambient air temp out of the vents. When you get on the gas it turns the waterpump faster which in turn moves that air pocket to another spot in the cooling system giving you heat while driving around. So he knew the headgasket was blown for sure but when they went in and did more looking around with the head off they saw a lot more issues.