Just purchased a 2007 suburban ltz. The guy I bought it from says he thinks the lifters have been replaced before he bought it. The afm is still enabled, and I want to get rid of it so it doesn't cause me any issues. I know I can either buy the range obdII port disable tool or get a tune. Would there be any harm if the lifters have been replaced in getting a tune? No paperwork to back it up. It has 174,000 miles
Do I need to delete AFM?
- Thread starter RAWVORTEC
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swathdiver
Full Access Member
Not really unless you run it hard and spin high rpms all the time. Do some detective work and see if you can find any service records. The CarFax for mine showed the names of two dealerships which I called and they kindly emailed me all the work done on the truck. Also sent a letter to the previous owner which went unanswered.
After getting a BlackBear tune and turning off AFM the service records revealed that just before I bought it, the entire AFM system was replaced with all the latest parts.
13yukonNJ
TYF Newbie
I don't know why I never thought to do this. I just emailed the service department at the dealership where the previous owner of my truck would take it to be serviced to see if they'll send me their records. I hope they are able to.
EDIT: And to stay on topic, my suggestion would be to leave the vehicle as-is. If it's made it this far without consuming oil I would say just keep being diligent about oil changes.
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iamdub
Full Access Member
If you can find out if the lifters had been replaced, try to find out if it was with the redesigned ones. There's an updated VLOM, too. If it were me and I couldn't confirm either one, I'd at least have it disabled with a tune or Range module. The only way to ensure that it will never be a problem is to remove (delete) it. Disabling it should at least buy you time, though.
swathdiver
Full Access Member
The new and old VLOMs are visually different so one is able to determine if at least that part has been changed on a pre-April 2011 (if memory serves) build.
iamdub
Full Access Member
I just re-read what I wrote. To clarify, what I meant by confirming either one was if the lifters had been replaced and, if so, was it with the redesigned ones.
On that note, I didn't know the VLOM looked externally different. I swear mine has a date of 2014 stamped on it but I didn't know I could tell by it's appearance. Googling!...
swathdiver
Full Access Member
I got ya, such is tough to tell! And there are three designs and the first two are far less reliable then the final Delphi II De Ac lifters which are the same ones used in the Gen V motors.
NathanS
Member
I just went down this same road. If you just bought it, drive it for a while and keep an eye on oil consumption. If it doesn’t burn oil then just leave it. I was burning to much oil for my liking and decided to delete AFM. When I got down to the short block I ended up pulling it and having it rebuilt with a new cam.
trailblazer
Full Access Member
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What ups my chances of not having AFM problems? I just picked up a ‘09 with about 93,000 miles and the previous owner used synthetic since when it bought it at 20,000 miles.
Are there any known best practices that seem to prevent AFM-related calamities?
Are there any known best practices that seem to prevent AFM-related calamities?
swathdiver
Full Access Member
It could run trouble free forever or drop dead tonight. Most of us disable the system in the tune to lessen the chance of failure and when a lifter eventually fails, we remove the whole system physically from the engine.
In 2011 the VLOM, lifters and driver's side valve cover were all improved. Under the oil pressure sensor, which is under the intake in the back, is a little filter for the VLOM that gets clogged after time and its worth inspecting or replacing.
Dirty oil is AFMs worst enemy. It is good that your motor has had synthetic oil and hopefully it was frequently changed and not left in there forever.
