So i checked the oil and it was a little low and pulled my plugs and checked them. #1. the plugs were gapped from .028-.044. #2. a couple plugs had a little oil on them and my RPD unit is reading 3-4 degress the odd time with stock tune. so i drop if off at the dealer stock and go pick it up and the paper work saying all the plugs were gapped the same and they did a leak down test #1 & 2 cylinder 10% crank case, #3 cylinder 30% crank case and #4 cylinder 2% crank case and there saying the max spec is 25%, and topped it off with oil....in the end they were saying its not bad enought to rip the motor apart...like what should i do??? this dealer is good to me untill now....should i try another dealer or call GM? what do u guys think about this sittuation? thanks

 

If 25% is the max and you have 30% on one cylinder, why do they not feel the need to fix this? You need to bitch more and go up the chain of command.

 

I would fight it. Low Compression is no bueno...obviously.

 

im goin to go to the other dealer where my buddy is the service manager and show him the paper work and if he can do anything im calling gm....what do u guys think the cylinder rings are shot?

 

Low compression has to be either valve or piston ring related. A valve issue would obviously be much easier to deal with.

 

go out and blow the motor then get a new one so you wont have any problems lol

 

Who did the tuning and when was the last time it was logged?

 

a local buddy tuned it....last week its been logged and everythings all good still pulls like hell tho

 

well they already changed the valves and lifters about 3 months ag......so im thinkin its the rings.

 

if you're getting a 30% leakdown into the crankcase then it's either rings, a bad sleeve, or some combination there of. It's more likely to be a ring issue than a sleeve, but you can't rule it out until more troubleshooting is done

 

what kind of other tests can i do?....also another thing my tuner has trouble tuning wit the catless DP...like he will tune it and it will be perfect and then datalog a couple days later and when the tires spin it had about 8 degrees knock (only when the tires are spining) and he says its taking way to much fuel to get rid of the knock that somethings wrong but doesnt know what it can be?!? maby that can help u guys out a bit...so rite now its just tuned at 20psi and without touching fuel terms w/o catless DP and its fine....

 

Your car was knocking??...another no bueno and that could have blown the rings. Just can't get *too greedy* with timing/boost. When I first got my car, took it for a tune and it already had one installed! Motor was knocking....we dialed back timing a bit and backed off the boost a tad along with decreasing AFR for some enrichment. Knock gone. Power actually increased some.
You'll need to take it apart..sooner or later.

 

He might be flooding it rich if he's not used to tuning LNF's. .88 PE lambda is the sweet spot.

Most tuners that don't know DI go waaaaay rich.

 

If there is a mechanical issue with the motor then no amount of tuning can fix the issue at this point. Hopefully the tune isn't what caused the issues to begin with here.. You will unfortunately at the very least need remove the head in order to access the pistons and sleeves. You will need someone (preferably a mechinist, or an engine builder would be even better) to check the cylinder bore for gouges, scratches and bore roundness with micrometers. If no issues are found with the sleeve and the trueness of the bore then there's a good chance your rings are bad. Either way it sounds like that engine needs to come apart at some point..

I'm not trying to scare you by any means here, but if you really are leaking down that much into the crank case then those are really the only 2 possible issues going on mechanically.

 

ill let him know that...i think he knows what hes doin....he has a 06 solstice wit over 400hp....and he saying this is the only car hes had trouble on

 

ohh i know it has to come apart....and if i leave this issue what will happen?... im planing on selling the car in about a year or so anyways....well its not a aggressive tune either he just turned up the boost would that of done it ? i donno much about tuning thats y i dont do it lol

 

If it knocks 8 degrees, then something is very wrong. Sorry, but it was likely a bad tune.

 

hate to say it but i think your buddy might have inadvertently fucked your car up with a shitty tune.

 

That's not a DI engine, odds are it's way too rich.

 

Agreed from reading this the tune is the problem, and if it's been to the dealer already, your gonna find warranty work harder to justify.

 

the only tuning he has done is turned the boost to 20 and no time nothin....so u guys r sayin throw the stock tune back on and fine someone elts to tune after its fixed and broking in again?!?!...i cant make it to the dealer till next monday due to the guy i wanna talk to is on vacation till then....

 

If he raised the boost and left the stock PE lambda, it was running lean at WOT in the midrange, not rich. Midrange PE Lambda stock is .95 from 2000 to 4000 rpm. That's almost 14:1 AFR, pretty damn lean to make any power, but might knock like all hell and crack the ring lands. It's just speculation at this point.

Get an LNF tuner to help you after it's repaired and broken in again IMO.

 

k thanks for the help....im goin to send him the link and im sure he can explain it better

 

Hi, let me go ahead and interject here. Sup Broke

Car is running .88 to .87 lambda, conservative dal's, and stock timing. His maf got dialed in and car pretty much flatlines at 0/0 ltft/stft. Every time the car left my hands, there was 0 knock. Untill it returned one day for a relog and retune with a catless it was rocking a solid 4-8 degrees of knock whenever it broke loose, the car also had a engine overspeed code which lead me to believe it was a miss-shift and he floated some valves. The leakdown tests would confirm this.

And yeah, after the car came back with the overspeed code it's been a pure ****. Only LNF I've ever seen exhibit this kind of ****. Random knock everywhere, random evap codes, etc.

*Edit: Mine is a 07 GXP, not an 06.

 

Well, I hope we didn't offend you, he never said who tuned it, just his 'buddy'. Coulda been any old Joe with HPT. He might have a cracked cam follower or valve /spring issue like you say if it was overrevved. Thanks for the updated info.

Nice to see you slummin' over here.