LT6 engine failures/problems
Race Director
Joined: Nov 2017
Posts: 12,759
Likes: 10,655
From: Prosper TX/Austin TX
2020 C6 of the Year Winner - Modified
I've got neither the knowledge or track experience to know if this guy is on to something or not. I'm not an auto engineer. Though I'm not a "black-belt" track guy, I do have a lot of track experience in my C6Z06, my C7 Grand Sport, and now my C8Z06. I've got 4,500 miles on my Z06 including 6 track days. I've not experienced issues similar to Vette Titans. I've totally enjoyed the car on track.
The engine is holding up, so far, and oil levels have remained steady. I haven't had to add a drop. I did a complete oil, DCT fluid and DCT filter change just before I hit 2,000 miles and after 2 track days.
The guy has stream of conscience complaints.....first it was the ELSD, then the carbon ceramic brakes, then the "tick", then the ABS, then gasoline in the oil. I don't know. Maybe we're the fools, not him. We'll see, I guess.
The engine is holding up, so far, and oil levels have remained steady. I haven't had to add a drop. I did a complete oil, DCT fluid and DCT filter change just before I hit 2,000 miles and after 2 track days.
The guy has stream of conscience complaints.....first it was the ELSD, then the carbon ceramic brakes, then the "tick", then the ABS, then gasoline in the oil. I don't know. Maybe we're the fools, not him. We'll see, I guess.
The DCT has been shown, imo, to be a crap shoot in terms of reliability. I'd never own a C8 out of warranty.
All that being said, this guy is just running his mouth about who knows what & from what I've seen, doesn't have any actual proof of anything to back it up.
Racer
Joined: May 2021
Posts: 403
Likes: 64
Tires hop when cold. He's completely right about this. I see the solution would be to program in power limitations in first and second gear until the car has been subjected to progressively increasing throttle inputs and/or cornering forces. This is the norm for motorcycles made by the Japanese manufacturers so novices don't kill themselves in first gear. I see the logic in this and what he is saying makes sense. I also have a science degree and understand physics. But I'm not an engineer. Do we have some engineers here who can make a statement about this?
Last edited by douglasjre; Sep 22, 2023 at 12:50 AM.
Melting Slicks
Joined: Jan 2002
Posts: 3,186
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@Redc8z06 What authority confirmed this?
Race Director
Joined: Nov 2017
Posts: 12,759
Likes: 10,655
From: Prosper TX/Austin TX
2020 C6 of the Year Winner - Modified
Neither Tadge nor Harlan are going to tell anybody anything about a potential problem with the vehicle, especially at Carlisle.
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Melting Slicks
Joined: Jan 2002
Posts: 3,186
Likes: 1,764
Now if someone really does have gas in their oil system then the issue maybe a faulty fuel injector or other issues listed below but not necessary a major design issue.
https://www.azom.com/article.aspx?ArticleID=16891
Last edited by Redc8z06; Sep 22, 2023 at 02:46 PM.
Race Director
Joined: Nov 2017
Posts: 12,759
Likes: 10,655
From: Prosper TX/Austin TX
2020 C6 of the Year Winner - Modified
2. They're not going to tell you or anybody anything about a potential problem with the car. Ask them about the continued DCT replacements four model years in and they'll probably tell you some bs like "customers just aren't used to the driving characteristics of a DCT..."
3. oil smells like gas now, got it
* Tadge also said the LS7 didn't have problems, that C7 GS & Z06 wheels didn't bend/crack
Pro
Joined: Jul 2023
Posts: 607
Likes: 559
Seems like the very early cars, some of those cars had some motor issues. I'm not hearing much about later-built MY2023 engines having issues.
Just my anecdotal observation. I don't have data to back this up, partly because GM doesn't share that data.
Just my anecdotal observation. I don't have data to back this up, partly because GM doesn't share that data.
Cruising
Joined: Jul 2017
Posts: 11
Likes: 3
Dropped Valve
Just came across this video on youtube. LT6 seized up at 621 miles. Not a ton of info. Owner basically says he did a proper break in. They were doing a little pull (its in the video, nothing crazy) and the engine started knocking and seized. City Chevy had a new engine in the car in about 2 weeks. GM didn't let the dealer open up the engine, I assume they had to ship it back to GM intact for some analysis.
Owner of the car says he knows of 3 engine failures. The one that died at like 50 miles that we all heard about, one other one, and his. So with about 1000 cars built, 3 engine failures. So about a 0.3% failure rate so far.
https://www.youtube.com/watch?v=eCfS12zAEKQ
Owner of the car says he knows of 3 engine failures. The one that died at like 50 miles that we all heard about, one other one, and his. So with about 1000 cars built, 3 engine failures. So about a 0.3% failure rate so far.
https://www.youtube.com/watch?v=eCfS12zAEKQ
Pro
Joined: Jul 2023
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@Bob Peters Just FYI - you can edit a reply/post to add more text, rather than creating 3 separate replies.
Race Director
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From: moraga ca
Drifting
Joined: Dec 2010
Posts: 1,778
Likes: 1,551
From: Las Vegas NV
My 23 Z06 dropped a valve (and maybe some other failure?) at 3569 miles. I also got a complete, new engine, but my car was off the road for a month. I did a proper break in, as I did with my 2016 C7 Z06 and a prior 2021C8 Z51. I would echo the video in praising the dealer's service advisor and daily communication of what was going on, I have the car back, fully broken in (roughly 2400 miles on the new engine), again, and she's gong to the track for her inauguration this weekend. We'll she how she does! Oh, and mine is Smurf Blue (that's really what Rapid Blue is, isn't it?) and her name is, you guessed it, Smurfette.
Pro
Joined: Nov 2017
Posts: 713
Likes: 506
Ok so you are calling me a liar got it and it's not a potential problem (yet) in some cases it's not gas entering the oil system but a miss understanding from some owners smelling what they believe to be gas in their oil system but it's actually the smell of the oil itself. If the oil level on your dip stick doesn't increase than gas can't be entering your oil system.
Now if someone really does have gas in their oil system then the issue maybe a faulty fuel injector or other issues listed below but not necessary a major design issue.
https://www.azom.com/article.aspx?ArticleID=16891
Now if someone really does have gas in their oil system then the issue maybe a faulty fuel injector or other issues listed below but not necessary a major design issue.
https://www.azom.com/article.aspx?ArticleID=16891
I have 15 cases of M1 Supercar 5w50 at work. I walked back and just opened one up, took a bottle out and cracked that open. It does NOT AT ALL smell like gasoline. None whatsoever. It has a sweet synthetic oil smell (actually kind of nice smelling lol).
Fuel smell in engine oil? = Fuel dilution. Where that dilution is coming from? Most likely causes are rings not seated, hung injectors or? Idling the car too much. I suppose that if these run rich it could lead towards it as well. As seen with the LT2, they do NOT like to sit idling for more than a minute after a cold start at the most. We've had 4 customers come with fouled plugs on LT2s because they did the old "start it once a month in storage and idle it for 10 minutes" only to have it towed to us running on 3 cylinders.
Also. You can have fuel dilution without a rise in oil level. You'd have to be losing a LOT of fuel into the oil to get a rise in level. Think Chevy Equinox with the 2.4 Ecotec where in 3000mi they'd come in 1/2 quart high, or more so well past 3% of the oil in the sump on those 5 quart systems.
@Mitchell_B what was the percentage for dilution? Ideally no more than 1.5% is ideal, anything past that is concern, above 3% there's problems.
Last edited by Newdude; Oct 23, 2023 at 04:02 PM.