Author Topic: possible engine issue (Read 13063 times)

boardkat · « **Reply #25 on:** March 14, 2011, 03:41:37 PM »

bumping this back up.

latest update: back in january, GM instructed the dealership to give me the car back to run a few tanks of "top tier gas" through, to see if injectors are clogged, carbon buildup, etc. i knew this wouldn't fix anything, but understand how warranty work is. gave it back to them in the middle of january, when GM then flew in a TAC field engineer to inspect. nothing dysfunctional electrically, conclusion was there must be something failing mechanically, especially since no codes have ever been thrown for the misfiring second cylinder. dealership pulled the head, checked tolerances, nothing out of the ordinary. GM decided that replacing the valve springs would be the next step, but head bolts were on national backorder (!), so they opened a SPAC case to get some made. finally arrived last week, and the engineer flew back out to inspect and help put the engine back together. he noticed some scoring on the rocker arms and suspects that a dry run condition could have been encountered multiple times - plausible to me, the previous owner had the car for a year and a half and only put 1200 miles on it, while it sat most of the time in an airplane hangar. i also suspect possible QC issues, if my past experiences with the kappa platform are any indication, but frankly, i don't really care, i just want my car back and running the way it was intended!!

bottom line, they've ordered a new head/cams/etc and will be putting the engine back together next week. fingers crossed, i'm cautiously optimistic.

TomatoSoup · « **Reply #26 on:** March 14, 2011, 04:26:57 PM »

Ouch! Good luck, hope for the best & let us know...

Critterman · « **Reply #27 on:** March 14, 2011, 05:51:16 PM »

Let's hope this takes care of all your issues.

boardkat · « **Reply #28 on:** March 24, 2011, 08:20:17 PM »

another update: new head, rockers, valve springs, etc are on. misfire decided to stick around

TAC office was already closed for the day, but it gave the service manager and me a chance to have a good discussion. we're on the same page, i have an advocate not an adversary, which is not what i was expecting when i started this whole process. i suggested that when they talk to TAC again, if they truly think it's a mechanical issue, then to have them send out a new long block, new engine harness and new sensors, and figure out the issue on their own time. we'll see if GM agrees. i just want to drive!!!

Graywolf · « **Reply #29 on:** March 24, 2011, 09:13:34 PM »

How is WOT in 1st and 2nd or do you have issues in all gears. Some times a simple blow off valve spring can be bad but it usually spits out a code Its progressively decreases power because of back pressure is not relieved when you shift gears.

boardkat · « **Reply #30 on:** March 24, 2011, 09:50:20 PM »

it happens under WOT in all gears. first two it'll happen pretty consistently on a level surface, otherwise (and in addition to) 3/4/5 it'll happen under load (up an incline).

and yeah, no codes. ever.

Graywolf · « **Reply #31 on:** March 24, 2011, 10:56:24 PM »

Have they checked the fuel pressure? What kind of boost are you getting? Open your air filter box and make sure a mouse did not make a nest in there. They may need to change the ecm unit. Could your exhaust be plugged ? Since you do not know all the history on this car. I feel your frustration,these cars are too hard to diagnose.

Dave@DDMworks · « **Reply #32 on:** March 25, 2011, 12:12:26 PM »

If you can, find out if they replaced the timing chain tensioner when they did the head, we have seen issues with the timing chain tensioner on the Ecotecs that will cause problems like you are describing.

Graywolf · « **Reply #33 on:** March 25, 2011, 11:53:51 PM »

Agree with Dave but this usually throws a code. I just replaced my chain and sprochet. I'm using a stiffer spring for chain tensioner

NormSky · « **Reply #34 on:** March 26, 2011, 12:35:15 AM »

Does the oxygen sensor give feedback to the ECU on the LNF?

Sol Asylum · « **Reply #35 on:** March 26, 2011, 06:14:17 PM »

Quote from: NormSky on March 26, 2011, 12:35:15 AM

Does the oxygen sensor give feedback to the ECU on the LNF?

Where else would it go?

NormSky · « **Reply #36 on:** March 27, 2011, 03:26:24 PM »

SA, the stock naRrow band in most cars today gets over rided during power enrichment. Just curious if the LNF WB does the same or not and if the information is getting skewed returning to the ECU?

boardkat · « **Reply #37 on:** March 27, 2011, 08:31:48 PM »

Quote from: Dave@DDMworks on March 25, 2011, 12:12:26 PM

If you can, find out if they replaced the timing chain tensioner when they did the head, we have seen issues with the timing chain tensioner on the Ecotecs that will cause problems like you are describing.

thanks, dave. haven't seen an itemized receipt of all the work they've done so i'll forward that info along.

boardkat · « **Reply #38 on:** March 27, 2011, 08:32:52 PM »

Quote from: BlackSunShine on March 27, 2011, 08:03:57 PM

Minus the leak, this sounds exactly like what I had going on. No one could find the issue....and as of today, the hesitation is back.

what did they do to diagnose/fix? sounds like i'll probably be getting a new longblock, did they go that far with yours?

boardkat · « **Reply #39 on:** April 08, 2011, 02:21:11 PM »

most recent update: the TAC techs are stumped. when i spoke with the dealership yesterday (we've been in touch on a weekly basis), they wanted them to regap the plugs. yeah, not like they hadn't already swapped plugs/coils/checked gap already!!

final straw as far as i was concerned - if the TAC techs are running the show as far as troubleshooting and authorizing repairs goes, the time had come for escalation to somebody on the business side that thinks in dollars and "sense", not nuts and bolts. which is exactly what i did - to all those that have felt helpless calling the GM customer service line and not getting anywhere, let me be the one to tell you that there's sometimes light at the end of the tunnel! the lady i spoke with yesterday wasted no time opening a case outside of her department, immediately involving the dealership, and getting in touch with a district manager. i got a phone call from the dealership service manager and DM this morning, wanting to get my whole perspective on the issue - do i want a GM buyback, an engine teardown with possible longblock replacement if necessary (and compensation for lost value/downtime), etc. fingers crossed that they actually find something, but i feel at least we've entered the endgame as far as getting my car fixed is concerned. stay tuned!!

Critterman · « **Reply #40 on:** April 08, 2011, 02:32:52 PM »

That is good news, you have several options available to you. Keep us advised.

Arabas · « **Reply #41 on:** April 08, 2011, 03:31:54 PM »

you certainly found someone decent enough to do the job!
hope it all goes well from here on!

1LILNDN · « **Reply #42 on:** April 08, 2011, 08:36:14 PM »

Don't choke to hard when She offers you " compensation " your not doing anything different then what I've done .even when you bit^h you won't get any gratification . GM Sucks in that Dept.

boardkat · « **Reply #43 on:** April 09, 2011, 03:09:47 AM »

Quote from: 1 LIL NDN on April 08, 2011, 08:36:14 PM

Don't choke to hard when She offers you " compensation " your not doing anything different then what I've done .even when you bit^h you won't get any gratification . GM Sucks in that Dept.

i know what i've been told, and it falls in line with my expectations given the circumstances (both in repair and buyback scenarios). i'll keep ya posted when the cards fall.

boardkat · « **Reply #44 on:** May 02, 2011, 01:48:38 PM »

this wild ride is finally coming to a close. unable to secure the necessary electrical components (wiring, sensors), and with no ETA/prioritization internally to have the parts manufactured, the district GM has asked me to gather documentation related to my purchase in the interest of buying the car back. this is a very unfortunate development, in spite of the problems i've had since the day i bought it, and the amount of time i haven't even had to enjoy it while fixes were attempted. this is the exact car that i've coveted for years, and not the road i ever wanted to go down. not sure what else to say other than that.

RIP GXP 5MT Sly Coupe #802

Arabas · « **Reply #45 on:** May 02, 2011, 02:10:44 PM »

boardkat, can you buy a used coupe, after you sell this one?

boardkat · « **Reply #46 on:** May 02, 2011, 02:27:55 PM »

Quote from: Arabas on May 02, 2011, 02:10:44 PM

boardkat, can you buy a used coupe, after you sell this one?

not sure my heart can take any more abuse, after the issues i had with my 'vert and now the coupe. i'm probably gonna take a step back and figure everything out for awhile before i make any decision.

G8TR · « **Reply #47 on:** May 02, 2011, 02:30:21 PM »

Amazing that you have had severe problems with both. Hope you find what you want and which is reliable for you.

Arabas · « **Reply #48 on:** May 02, 2011, 02:43:37 PM »

damn, the coupe is amazing! i would buy it with eyes closed...
hope you find a problem free ride!!

Critterman · « **Reply #49 on:** May 02, 2011, 02:46:16 PM »

Good luck in what ever you decide to do.

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Author Topic: possible engine issue (Read 13063 times)