[ZR1] LS9 valve-train matters reported on the CF
08-23-2015, 12:36 PM
#21
Pro
Novice to ZR1's but not to engines, so here is a thought: seems cheaper to buy a GMEPP than head removal and guide replacement, even if nothing catastrophic happens (then it would be a no brainer).
Two different forms of insurance with potentially a big price difference.
(2010 ZR1/3ZR)
Two different forms of insurance with potentially a big price difference.
(2010 ZR1/3ZR)
08-23-2015, 11:13 PM
#22
Race Director
Thread Starter
That's exactly what I did (same yr/model), but I will have the heads properly inspected, at my cost if necessary, before the expiration of my GMPP.
The guides do wear and eventually will need to be fixed.
The guides do wear and eventually will need to be fixed.
08-24-2015, 09:19 PM
#23
Pro
May not be new info as such but in talking to Top Flight Corvette here in San Diego, a few things mentioned:
1) When you cold start your car does it expel a puff of white smoke right at start and produce the noise that previous posts referred to.
2) Watch your oil consumption. Apparently a "normally driven" car will use about 1/2 quart between oil changes. YMMV of course. Measure it though so you have a reference.
3) In most cases be it the LS7 or 9 when he has to remove the heads, he suggested replacing the guides but also replacing the exhaust valves. SOmething to do with the materials used by GM (??). And if he has heads opened, he highly suggests their replacement. I didn't ask replaced with what.
He has seen LS7's and 9's with tons of miles on them that are perfectly fine.
If #1 and #2 are happening. The signs are probably there.
1) When you cold start your car does it expel a puff of white smoke right at start and produce the noise that previous posts referred to.
2) Watch your oil consumption. Apparently a "normally driven" car will use about 1/2 quart between oil changes. YMMV of course. Measure it though so you have a reference.
3) In most cases be it the LS7 or 9 when he has to remove the heads, he suggested replacing the guides but also replacing the exhaust valves. SOmething to do with the materials used by GM (??). And if he has heads opened, he highly suggests their replacement. I didn't ask replaced with what.
He has seen LS7's and 9's with tons of miles on them that are perfectly fine.
If #1 and #2 are happening. The signs are probably there.
The following 2 users liked this post by LGK-SD:
94-vette (02-06-2021),
speedwaywhite (06-29-2017)
08-27-2015, 08:39 PM
#25
Team Owner
08-28-2015, 06:53 AM
#26
I have zr1 with American racing headers long tube without cats and with tuned? Tha question is why I feel the car throttled? Should I change the cats? Someone help plz
08-31-2015, 07:58 PM
#27
im going to be in the market for a used ZR1, are these issus only with the factory heads/ valvetrain? reason i ask is because i will quickly be doing a heads cam package so am curious as to how worried i should be if its an overall design flaw or just bad factory parts?
08-31-2015, 11:10 PM
#28
Race Director
Thread Starter
The majority of the reports on the attached list (see thread-links) are with cars having OEM engines; at least two were cars with modified engines.
The overall cause has not been clearly identified, as with somewhat similar issues with the LS7. Hopefully by reading the referenced reports
you can become better informed as to what steps may need to be implemented regarding the LS9.
The overall cause has not been clearly identified, as with somewhat similar issues with the LS7. Hopefully by reading the referenced reports
you can become better informed as to what steps may need to be implemented regarding the LS9.
09-03-2015, 05:15 PM
#29
Premium Supporting Vendor
Novice to ZR1's but not to engines, so here is a thought: seems cheaper to buy a GMEPP than head removal and guide replacement, even if nothing catastrophic happens (then it would be a no brainer).
Two different forms of insurance with potentially a big price difference.
(2010 ZR1/3ZR)
Two different forms of insurance with potentially a big price difference.
(2010 ZR1/3ZR)
09-19-2015, 05:39 AM
#30
Hey Gary:)
Hey wanna ask you about corvette Zr1 what is the best pulley for it?
Does lingenfilter pulley package is enough? Or should add harmonic balancer with it?
My Zr1 only with American Racing headers with stock exhauste system so what do you think which pulleys better for my car? Need your advice plz👍
Does lingenfilter pulley package is enough? Or should add harmonic balancer with it?
My Zr1 only with American Racing headers with stock exhauste system so what do you think which pulleys better for my car? Need your advice plz
👍
09-19-2015, 09:15 PM
#31
Race Director
Thread Starter
Hamado, please start a separate thread in the ZR1 sub-forum for your questions about specific modifications for the LS9.
This "sticky thread" is intended to be a "gathering point" for CF members to report information about valve-train defects/issues,
and it would be helpful to everyone to keep the thread "on topic."
I suspect you would also receive responses to your inquiries if you removed both from this thread, and asked both again
in a new separate thread. It is likely more CF readers would see your questions, and those with the appropriate knowledge
might supply relevant comments & advice. I for one do not know the answers to your questions...
thanks Gary
This "sticky thread" is intended to be a "gathering point" for CF members to report information about valve-train defects/issues,
and it would be helpful to everyone to keep the thread "on topic."
I suspect you would also receive responses to your inquiries if you removed both from this thread, and asked both again
in a new separate thread. It is likely more CF readers would see your questions, and those with the appropriate knowledge
might supply relevant comments & advice. I for one do not know the answers to your questions...
thanks Gary
11-06-2016, 09:17 PM
#34
Pro
I just had my heads pulled and inspected. Both heads had valve guide wear. My ZR1 is a 2010 with 50k miles on it. Slightly modded, 2.3 upper pulley and a tune.
03-19-2017, 10:00 AM
#36
Melting Slicks
I passed on a 2012 Z06 with 15k miles because of the head issue...
Now I'm looking at a mint 2010 ZR1 with 16k miles...should I back off also? After seeing this forum..I'm having second thoughts about it..
Now I'm looking at a mint 2010 ZR1 with 16k miles...should I back off also? After seeing this forum..I'm having second thoughts about it..
Last edited by chassed; 03-19-2017 at 10:00 AM.
03-19-2017, 10:21 AM
#37
Pro
IMO, regardless of what model you decide to buy, you should have the heads checked. I have a 2010 ZR1, the first thing I did was have the heads inspected. Turned out there were a few valves that were out of spec. I got the heads addressed, and now shouldn't have any worries
Last edited by Ricky218; 03-19-2017 at 10:25 AM.
03-20-2017, 11:16 PM
#38
Melting Slicks
IMO, regardless of what model you decide to buy, you should have the heads checked. I have a 2010 ZR1, the first thing I did was have the heads inspected. Turned out there were a few valves that were out of spec. I got the heads addressed, and now shouldn't have any worries
Did you have a machine shop correct the spec issue? Or did you upgrade heads?
03-21-2017, 12:17 AM
#39
Pro