Blown LS7 - Need advice *long post*
02-11-2018, 11:13 AM
#21
Racer
Thread Starter
Member Since: Feb 2007
Location: Irvine / Rancho Cucamonga CA
Posts: 294
Received 0 Likes
on
0 Posts
Even if the motor had no oil and wore the cross hatching off, the result would not be what happened. A seized motor, spun bearing(s), broken rings maybe. But not the broken valve which is, iirc, what likely scored the wall.
I will say that it is odd that there is no crosshatching left (If that's even true) but again, that isn't why the motor failed.
And nd even if it was a problem, it could have ran for years like that. But it obviously won't run for years (or even 300 miles) without the caps.
I will say that it is odd that there is no crosshatching left (If that's even true) but again, that isn't why the motor failed.
And nd even if it was a problem, it could have ran for years like that. But it obviously won't run for years (or even 300 miles) without the caps.
02-11-2018, 02:51 PM
#22
Tech Contributor
Member Since: Oct 1999
Location: Charlotte, NC (formerly Endicott, NY)
Posts: 40,096
Received 8,930 Likes
on
5,334 Posts
Another thing the dealer pointed out was that the cylinders were no longer honed which caused oil to leak into the cylinders. They're acknowledging that the machine shop improperly repaired the heads but insist that the engine failure was due to this cylinder honing problem. I just can't see how these two things would be unrelated
Bill
Last edited by Bill Dearborn; 02-11-2018 at 02:55 PM.
The following users liked this post:
z06brah (02-12-2018)
02-11-2018, 06:39 PM
#23
Instructor
Member Since: Sep 2010
Location: San Diego California
Posts: 152
Likes: 0
Received 7 Likes
on
5 Posts
Ls7
The intake valves are titanium. The valve cannot handle being in direct contact with the rocker arm. That is why GM uses a lash cap between the rocker tip and the top of the valve!!! This is obvious damage from running no lash caps. Mechanic error!!!!!!!!!!!!!!!!!
Need more info about the short block but it sounds like an upsell!!!!Call me and I will educate further. The call is cheap. The savings will likely be thousands!
Gary
Need more info about the short block but it sounds like an upsell!!!!Call me and I will educate further. The call is cheap. The savings will likely be thousands!
Gary
The following users liked this post:
z06brah (02-12-2018)
02-11-2018, 07:38 PM
#25
Melting Slicks
Let's assume there is no damage to the cylinder wall or piston. The inside of the motor is full of debris from the valve failures, which was caused by the mechanic not installing lash caps.
Some might think that the oil filter will remove the debris. This is true to a certain extent, the filter will remove some but not all. Once the filter starts to get full of debris, the bypass opens and sends unfiltered oil through the engine and into the bearings.
Consider the unfiltered oil that had to drain back from the heads across the cam and lifters on to the rotating assembly which then flung the contaminated oil onto the cylinder walls where it becomes embedded in the skirts of the piston.
I've seen motors with valve train and camshaft failures many times, it is not pretty.
They will want to install a new set of heads and "flush" the engine. You are guaranteed to have more trouble with that engine down the road as it slowly eats itself over time from all the debris.
Some might think that the oil filter will remove the debris. This is true to a certain extent, the filter will remove some but not all. Once the filter starts to get full of debris, the bypass opens and sends unfiltered oil through the engine and into the bearings.
Consider the unfiltered oil that had to drain back from the heads across the cam and lifters on to the rotating assembly which then flung the contaminated oil onto the cylinder walls where it becomes embedded in the skirts of the piston.
I've seen motors with valve train and camshaft failures many times, it is not pretty.
They will want to install a new set of heads and "flush" the engine. You are guaranteed to have more trouble with that engine down the road as it slowly eats itself over time from all the debris.
The following users liked this post:
z06brah (02-12-2018)
02-12-2018, 04:14 PM
#26
Supporting Vendor
Member Since: Sep 2013
Location: Harbor City California
Posts: 2,817
Received 1,012 Likes
on
533 Posts
Lash Caps were left off!!!!
100% installation error by who ever put the heads back on the car. The dealer owes you a brand new engine plug a proper set of reworked heads.
310-326-2399
http://www.americanheritageperformance.com/
100% installation error by who ever put the heads back on the car. The dealer owes you a brand new engine plug a proper set of reworked heads.
310-326-2399
http://www.americanheritageperformance.com/
The following users liked this post:
z06brah (02-13-2018)
02-12-2018, 05:32 PM
#27
Safety Car
Unfortunately you have learned what many of us have learned; that the dealer is a great place to go for warranty repairs on a recently built and sold product, but is generally the last place to go for repairs out of warranty or that they don't totally control in house.
They picked a head shop that likely has a lot of experience with truck motors but has no experience with high performance products particularly with exotic materials like titanium valves. Very sorry you had to experience this problem. I presume they never measured the valve guides with a bore gauge to see if you really had a guide problem.
My 08 Z had a GM ext warranty til Sept of 16. I traded it that month (w only 20,000 miles on her) simply to avoid a valve guide problem out of warranty.
They picked a head shop that likely has a lot of experience with truck motors but has no experience with high performance products particularly with exotic materials like titanium valves. Very sorry you had to experience this problem. I presume they never measured the valve guides with a bore gauge to see if you really had a guide problem.
My 08 Z had a GM ext warranty til Sept of 16. I traded it that month (w only 20,000 miles on her) simply to avoid a valve guide problem out of warranty.
Last edited by pkincy; 02-12-2018 at 05:56 PM.
The following users liked this post:
z06brah (02-13-2018)
The following users liked this post:
z06brah (02-13-2018)
02-13-2018, 12:47 PM
#29
Racer
Thread Starter
Member Since: Feb 2007
Location: Irvine / Rancho Cucamonga CA
Posts: 294
Received 0 Likes
on
0 Posts
Quick update, I want to thank everyone for taking the time to reply here. I would have never known about the lash caps and their impact on the heads so I am extremely grateful to have this forum and you guys as a resource.
I did speak to the dealer yesterday and it became clear the service manager did not know what I was talking about. After some back and forth, they decided to do some research and this morning I received a call back from them acknowledging their mistake in forgetting to install the caps. They want to replace all the intake valves and assess for any other damage that might have occurred. At this point I don't know to what extent they will do their assessment.
One thing I'm a bit hung up on now is whether they will be able to fully assess the damage. On Saturday (2/10/18) the dealer was suggesting a complete new engine citing the cylinder walls as not being honed properly which would inevitably lead to oil/coolant getting into the engine again. Now that they have acknowledged their mistake in failing to install the lash caps which led to the failure, they are taking responsibility for replacing the intake valves but have made no mention now of the need for a replacement engine.
When I initially spoke with the service manager yesterday, one of the first questions I asked was if the block was cracked and his response was that it was not. Is it possible that it may actually be? Does a dropped valve more likely than not lead to a cracked block? Is it something that would easily be visible without pulling the engine out of the car or while it is up on a lift?
I did speak to the dealer yesterday and it became clear the service manager did not know what I was talking about. After some back and forth, they decided to do some research and this morning I received a call back from them acknowledging their mistake in forgetting to install the caps. They want to replace all the intake valves and assess for any other damage that might have occurred. At this point I don't know to what extent they will do their assessment.
One thing I'm a bit hung up on now is whether they will be able to fully assess the damage. On Saturday (2/10/18) the dealer was suggesting a complete new engine citing the cylinder walls as not being honed properly which would inevitably lead to oil/coolant getting into the engine again. Now that they have acknowledged their mistake in failing to install the lash caps which led to the failure, they are taking responsibility for replacing the intake valves but have made no mention now of the need for a replacement engine.
When I initially spoke with the service manager yesterday, one of the first questions I asked was if the block was cracked and his response was that it was not. Is it possible that it may actually be? Does a dropped valve more likely than not lead to a cracked block? Is it something that would easily be visible without pulling the engine out of the car or while it is up on a lift?
02-13-2018, 02:00 PM
#30
Safety Car
I suppose my inclination would be to ask for the $5k back and send the car over to Kohl. You really can't trust anything they say at this point. If they couldn't do it right the first time, I would have little faith that the 2nd time would be any better. Also their failure to put on the lash caps likely caused damage. How much you don't know yet. So simply putting the lash caps on is not going to fix the problem.
The following users liked this post:
whalepirot (02-16-2018)
02-13-2018, 02:16 PM
#31
Melting Slicks
Let's assume there is no damage to the cylinder wall or piston. The inside of the motor is full of debris from the valve failures, which was caused by the mechanic not installing lash caps.
Some might think that the oil filter will remove the debris. This is true to a certain extent, the filter will remove some but not all. Once the filter starts to get full of debris, the bypass opens and sends unfiltered oil through the engine and into the bearings.
Consider the unfiltered oil that had to drain back from the heads across the cam and lifters on to the rotating assembly which then flung the contaminated oil onto the cylinder walls where it becomes embedded in the skirts of the piston.
I've seen motors with valve train and camshaft failures many times, it is not pretty.
They will want to install a new set of heads and "flush" the engine. You are guaranteed to have more trouble with that engine down the road as it slowly eats itself over time from all the debris.
Some might think that the oil filter will remove the debris. This is true to a certain extent, the filter will remove some but not all. Once the filter starts to get full of debris, the bypass opens and sends unfiltered oil through the engine and into the bearings.
Consider the unfiltered oil that had to drain back from the heads across the cam and lifters on to the rotating assembly which then flung the contaminated oil onto the cylinder walls where it becomes embedded in the skirts of the piston.
I've seen motors with valve train and camshaft failures many times, it is not pretty.
They will want to install a new set of heads and "flush" the engine. You are guaranteed to have more trouble with that engine down the road as it slowly eats itself over time from all the debris.
02-13-2018, 02:16 PM
#32
Team Owner
That valve most likely came in contact with a piston correct? That whole motor should be disassembled and gone though. Especially since they told you there's cylinder wall damage...but going through a motor isn't the dealers forte. Precisely why, when they thought it was your problem (on your dime), they said you needed a whole new engine. Now that they are clearly to blame for the failure, and have accepted fault, they're changing their stance on needing a new engine.
That would be my question to them point blank....if the original diagnosis is engine replacement; why has that suddenly changed??
That would be my question to them point blank....if the original diagnosis is engine replacement; why has that suddenly changed??
02-13-2018, 03:08 PM
#33
Cruising is the passion!
Member Since: Jan 2003
Location: SIMSBURY CT
Posts: 6,140
Received 304 Likes
on
213 Posts
St. Jude Donor '07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20-'21-'22-'23-'24
I suppose my inclination would be to ask for the $5k back and send the car over to Kohl. You really can't trust anything they say at this point. If they couldn't do it right the first time, I would have little faith that the 2nd time would be any better. Also their failure to put on the lash caps likely caused damage. How much you don't know yet. So simply putting the lash caps on is not going to fix the problem.
02-13-2018, 03:54 PM
#34
Instructor
That valve most likely came in contact with a piston correct? That whole motor should be disassembled and gone though. Especially since they told you there's cylinder wall damage...but going through a motor isn't the dealers forte. Precisely why, when they thought it was your problem (on your dime), they said you needed a whole new engine. Now that they are clearly to blame for the failure, and have accepted fault, they're changing their stance on needing a new engine.
That would be my question to them point blank....if the original diagnosis is engine replacement; why has that suddenly changed??
That would be my question to them point blank....if the original diagnosis is engine replacement; why has that suddenly changed??
02-13-2018, 04:18 PM
#35
Quick update, I want to thank everyone for taking the time to reply here. I would have never known about the lash caps and their impact on the heads so I am extremely grateful to have this forum and you guys as a resource.
I did speak to the dealer yesterday and it became clear the service manager did not know what I was talking about. After some back and forth, they decided to do some research and this morning I received a call back from them acknowledging their mistake in forgetting to install the caps. They want to replace all the intake valves and assess for any other damage that might have occurred. At this point I don't know to what extent they will do their assessment.
One thing I'm a bit hung up on now is whether they will be able to fully assess the damage. On Saturday (2/10/18) the dealer was suggesting a complete new engine citing the cylinder walls as not being honed properly which would inevitably lead to oil/coolant getting into the engine again. Now that they have acknowledged their mistake in failing to install the lash caps which led to the failure, they are taking responsibility for replacing the intake valves but have made no mention now of the need for a replacement engine.
When I initially spoke with the service manager yesterday, one of the first questions I asked was if the block was cracked and his response was that it was not. Is it possible that it may actually be? Does a dropped valve more likely than not lead to a cracked block? Is it something that would easily be visible without pulling the engine out of the car or while it is up on a lift?
I did speak to the dealer yesterday and it became clear the service manager did not know what I was talking about. After some back and forth, they decided to do some research and this morning I received a call back from them acknowledging their mistake in forgetting to install the caps. They want to replace all the intake valves and assess for any other damage that might have occurred. At this point I don't know to what extent they will do their assessment.
One thing I'm a bit hung up on now is whether they will be able to fully assess the damage. On Saturday (2/10/18) the dealer was suggesting a complete new engine citing the cylinder walls as not being honed properly which would inevitably lead to oil/coolant getting into the engine again. Now that they have acknowledged their mistake in failing to install the lash caps which led to the failure, they are taking responsibility for replacing the intake valves but have made no mention now of the need for a replacement engine.
When I initially spoke with the service manager yesterday, one of the first questions I asked was if the block was cracked and his response was that it was not. Is it possible that it may actually be? Does a dropped valve more likely than not lead to a cracked block? Is it something that would easily be visible without pulling the engine out of the car or while it is up on a lift?
Unfortunately, it's likely that the repairs will be higher than the limits of small claims court, so you'll have to spend money getting a lawyer to sue the dealer, because it's unlikely that they will pony up upwards of $20k to replace the motor and associated parts.
FWIW, this should be a lesson to you as well. Never take your corvette to the dealer for repair, unless it's a new car and under warranty.
02-13-2018, 07:09 PM
#36
Team Owner
A dropped valve almost always leads to a cracked block, or at least damaged cylinder wall and piston. That is all on them.
02-13-2018, 07:33 PM
#37
Burning Brakes
That valve most likely came in contact with a piston correct? That whole motor should be disassembled and gone though. Especially since they told you there's cylinder wall damage...but going through a motor isn't the dealers forte. Precisely why, when they thought it was your problem (on your dime), they said you needed a whole new engine. Now that they are clearly to blame for the failure, and have accepted fault, they're changing their stance on needing a new engine.
That would be my question to them point blank....if the original diagnosis is engine replacement; why has that suddenly changed??
That would be my question to them point blank....if the original diagnosis is engine replacement; why has that suddenly changed??
02-15-2018, 07:13 PM
#39
Racer
Thread Starter
Member Since: Feb 2007
Location: Irvine / Rancho Cucamonga CA
Posts: 294
Received 0 Likes
on
0 Posts
Latest info I've received is that the dealer will be replacing intake valves. The #3 cylinder was determined to be the cylinder with the dropped valve but I was told there was no damage done to it and I am free to come see for myself tomorrow morning. Problem is, I don't really know what I'm looking at and what to look for so the only thing they are replacing as far as I am aware are intake valves.
I've talked to the dealer about replacing the engine and trying to meet in the middle and was told that the best they could do is credit me 5k that I paid toward the 17k total for the replacement engine.
I also reached out to a few attorneys in the area and was shocked that most refuse to work with cases against dealers. The few I did find were quoting me a third of the cost of an engine as a deposit with a 250/hr rate and non-contingent basis (meaning they don't know if I'll win, obviously). Additionally they mentioned that under the circumstances it would be hard to get a replacement engine fully paid for given my engine was 10 years old and had 75k miles (basically I could ask for fair market value and I don't know what that would be)
I spoke to AHP about all this and it looks like I'm going to have them fix the heads and ask the dealer to cover that cost. I really don't have any other option at this point.
I've talked to the dealer about replacing the engine and trying to meet in the middle and was told that the best they could do is credit me 5k that I paid toward the 17k total for the replacement engine.
I also reached out to a few attorneys in the area and was shocked that most refuse to work with cases against dealers. The few I did find were quoting me a third of the cost of an engine as a deposit with a 250/hr rate and non-contingent basis (meaning they don't know if I'll win, obviously). Additionally they mentioned that under the circumstances it would be hard to get a replacement engine fully paid for given my engine was 10 years old and had 75k miles (basically I could ask for fair market value and I don't know what that would be)
I spoke to AHP about all this and it looks like I'm going to have them fix the heads and ask the dealer to cover that cost. I really don't have any other option at this point.
Last edited by z06brah; 02-15-2018 at 07:13 PM.
02-15-2018, 07:29 PM
#40
Team Owner
If they are only going to do the valve, then I would get a very clear written warranty that if there is any further damaged, such as a cracked sleeve/etc they will repair that too for something like 12 months 12k miles.