Collapsed lifter problem
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,065
Likes: 41
From: Kensington PE
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,065
Likes: 41
From: Kensington PE
I thank you for asking. Appreciate it. We replaced all the lifters on the left side. Started it up and it ran good. Eventually the engine light came back on. I took it to an auto computer guru who said both rear O2 sensors were bad. I ordered new GM sensors and presently waiting for them to arrive. In the meantime they left the sensors disconnected and the car is almost running like a new car. I'm thinking their diagnosis was correct and finally will have a 100% running Corvette soon.
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,065
Likes: 41
From: Kensington PE
More problems /same thing!
The car after above repairs was running perfect.... for 50 miles. Developed a bad miss with engine light flashing. Back to mechanic who just called. Same cylinder number 7, with same problem. One of the new OEM lifter has collapsed and stuck down. I said don't fix it. I'll park it in the front lawn. New OEM parts fail, what are you going to do!!
Corvette Enthusiast
Joined: Oct 2007
Posts: 6,797
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From: So. Cal.
2025 C7 of the Year Finalist- Unmodified
2024 C7 of the Year Finalist - Unmodified
2023 C7 of the Year Finalist - Unmodified
Sorry to hear about this recent update. Hoping for the best for you.
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Safety Car
Joined: Jul 2019
Posts: 3,844
Likes: 1,302
From: nashville TN
The car after above repairs was running perfect.... for 50 miles. Developed a bad miss with engine light flashing. Back to mechanic who just called. Same cylinder number 7, with same problem. One of the new OEM lifter has collapsed and stuck down. I said don't fix it. I'll park it in the front lawn. New OEM parts fail, what are you going to do!!
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,065
Likes: 41
From: Kensington PE
Safety Car
Joined: Jul 2019
Posts: 3,844
Likes: 1,302
From: nashville TN
theres a lot o0f ways of matching top the parts. Brian tooley racing is an excellent place to start, Texas speed , lme, there a host of cam choices. cam decision is no small matter its the difference between a car that chops wood and runs like stock and sounds amazing and drives like crap. your tuner should be the first person to talk to. adding springs ,lifters and pushrods dod delete kit, valley pan vvt delete will run in the 2500-3k range depending pin what parts you choose
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,065
Likes: 41
From: Kensington PE
Update
At the moment I don't have the deep pockets need to replace cam, + + + , so I will park the car as winter is here.
It just seems hard to believe when I would be happy with a stock running car, that stock GM parts wouldn't fix the problem. I hear about other C7s out there driving around with no modifications to their lifers/cam combo.
How about the owner's suit against GM over this. Would there ever be any positive results from that ?
It just seems hard to believe when I would be happy with a stock running car, that stock GM parts wouldn't fix the problem. I hear about other C7s out there driving around with no modifications to their lifers/cam combo.
How about the owner's suit against GM over this. Would there ever be any positive results from that ?
Safety Car
Joined: Jul 2019
Posts: 3,844
Likes: 1,302
From: nashville TN
At the moment I don't have the deep pockets need to replace cam, + + + , so I will park the car as winter is here.
It just seems hard to believe when I would be happy with a stock running car, that stock GM parts wouldn't fix the problem. I hear about other C7s out there driving around with no modifications to their lifers/cam combo.
How about the owner's suit against GM over this. Would there ever be any positive results from that ?
It just seems hard to believe when I would be happy with a stock running car, that stock GM parts wouldn't fix the problem. I hear about other C7s out there driving around with no modifications to their lifers/cam combo.
How about the owner's suit against GM over this. Would there ever be any positive results from that ?
Advanced
Joined: Aug 2018
Posts: 90
Likes: 26
From a previous post in this thread...
"The mechanical implementation of the AFM system involves a set of solenoids in the lifter oil manifold assembly (LOMA) which direct oil pressure upon software command to collapse a plunger inside the AFM lifters to shut off those cylinders. The most common cause of AFM failures are issues related to that oil pressure system such as not keeping fresh oil in the engine, using the wrong viscosity oil, or running low oil pressure. If any such issues were involved with one AFM cylinder failure then the others could also have been compromised."
I believe this is located in the valley between the V. When dealers do warranty work on vettes for the collapsed lifter, they also replace this part.
"The mechanical implementation of the AFM system involves a set of solenoids in the lifter oil manifold assembly (LOMA) which direct oil pressure upon software command to collapse a plunger inside the AFM lifters to shut off those cylinders. The most common cause of AFM failures are issues related to that oil pressure system such as not keeping fresh oil in the engine, using the wrong viscosity oil, or running low oil pressure. If any such issues were involved with one AFM cylinder failure then the others could also have been compromised."
I believe this is located in the valley between the V. When dealers do warranty work on vettes for the collapsed lifter, they also replace this part.
Thread Starter
Burning Brakes
Joined: Mar 2002
Posts: 1,065
Likes: 41
From: Kensington PE
with the exception of the cam you would be able to use all oem ls parts to convert the lt engine over. still not exactly cheap but it can be done. best to save up over the winter and talk to your tuner and use the time to formulate a game plan thats a do it once and done plan
1. The aftermarket kits that replace a lot parts and sell for $2500-3000.... -or- 2. the conversion to LS style using mostly stock parts except the cam.
Pro
Joined: Mar 2002
Posts: 732
Likes: 138
From: Allen (DFW) Texas
The car after above repairs was running perfect.... for 50 miles. Developed a bad miss with engine light flashing. Back to mechanic who just called. Same cylinder number 7, with same problem. One of the new OEM lifter has collapsed and stuck down. I said don't fix it. I'll park it in the front lawn. New OEM parts fail, what are you going to do!!
On the other hand, if you are intent on eliminating the AFM entirely there is an old Hot Rod Magazine article that might be of interest. It's specific to the LS engine but I believe the parts/process are essentially the same for the LT engine. https://www.motortrend.com/how-to/si...el-management/
Advanced
Joined: Aug 2018
Posts: 90
Likes: 26
If I were spending my own dollars, versus a warranty repair (which is how my vette's issue was fixed), I would remove the AFM stupidity and consider it money-well-spent.
In fact... I am amassing (slowyly) a rainy day fund to do this in the future...
In fact... I am amassing (slowyly) a rainy day fund to do this in the future...
