2007 Suburban AFM... Lifter questions... real novice

yankeeslover · May 16, 2017

good afternoon, i have a quick question for the mechanics of this board. I just purchased a 2007 suburban with 115,000 miles on her. after I got her home the dealer advised me that he just had the motor all rebuilt.. Nice of him to tell me before correct? Anyways. i put 10 miles on the the truck and lost all my oil out of the rear seal.. Needless to say its back at the dealer having a new seal put in and a protective sleeve added to it... My question is. dumb question. I understand there are special lifters that are involved for the ATM... what happens if the mechanic doesnt know this and adds normal lifters and the not the AFM ones or put AFM lifters where the non afm lifters go and vice versa? will the AFM just not work? im just worried now that it was put together wrong... is this even possible to do? truck said it was going back and forth between 4 and 8 so it was working, but what happens if the 4 afm lifters were replaced with normal lifters?

diyer2 · May 16, 2017

I would want a refund. If they were that dishonest and poor mechanics to boot what else is going on.

Did it start making noise when you lost the oil?

newdude · May 16, 2017

If the AFM lifters were replaced with non AFM lifters and the AFM system was not properly deleted, you would end up with 8 junk lifters real quick as the computer will still cut oil flow to those 8 AFM lifters.

yankeeslover · May 17, 2017

I would want a refund. If they were that dishonest and poor mechanics to boot what else is going on.

Did it start making noise when you lost the oil?

I tried... told me afterwards there is no warranty in NY since it had over 100,000 miles... so im stuck with it now and a small loan to boot.. there was no noise at all, just started losing oil out of the rear seal... Mechanic replaced seal today and is keeping truck for couple days to drive it around to make sure its all good..

yankeeslover · May 17, 2017

If the AFM lifters were replaced with non AFM lifters and the AFM system was not properly deleted, you would end up with 8 junk lifters real quick as the computer will still cut oil flow to those 8 AFM lifters.

Boy, I hope not. I am assuming he replaced the lifters when he did the job. I am hoping that when the shop ordered the new parts it would have instructions with them... It sounds like a reputable shop who rebuilt motor, but im just concerned that the shop didn't know about the AFM system... I will probably never know until it goes.. I will be buying a range system in a week, i just hope i dont damage anything whiten the next week though, just in case.. Now, if i do install the range system, would i have to worry if the wrong lifters were installed or not?

Podor · May 17, 2017

So, is this a real dealer, like a dealer with a new car line? If I'm not mistaken, you have 10 days to return a financed vehicle. You might want to call the local district attorney.

Most of the time, the cam has a different profile on the AMF cylinders, so it would run pretty poor with the wrong lifters. What is the "protective sleeve" they're putting in? Back in the day, the rear main seal used to wear a groove in the crank making it hard for the seal to stay tight to the crank. They used to make a thin sleeve that would go over the crank to cover the groove and keep the sealing surface true. That is Highly unlikely on an LS. I haven't heard of that in years. There are a few places that can cause a leak on an LS. If it's out the bell housing, it could be the rear main seal or rear main seal housing. It could be the oil pressure sensor, which would leak down the outside of the bell housing. It could be a side main bolt, going through the side of the block into each main cap. That would drip down the oil pan.

yankeeslover · May 17, 2017

So, is this a real dealer, like a dealer with a new car line? If I'm not mistaken, you have 10 days to return a financed vehicle. You might want to call the local district attorney.

Most of the time, the cam has a different profile on the AMF cylinders, so it would run pretty poor with the wrong lifters. What is the "protective sleeve" they're putting in? Back in the day, the rear main seal used to wear a groove in the crank making it hard for the seal to stay tight to the crank. They used to make a thin sleeve that would go over the crank to cover the groove and keep the sealing surface true. That is Highly unlikely on an LS. I haven't heard of that in years. There are a few places that can cause a leak on an LS. If it's out the bell housing, it could be the rear main seal or rear main seal housing. It could be the oil pressure sensor, which would leak down the outside of the bell housing. It could be a side main bolt, going through the side of the block into each main cap. That would drip down the oil pan.

No, It was a used car dealer. Truck looked mint.. inside and out.. i figured only 115,000 miles on it and was asking under 10 grand, which around here is a steal for a Suburban. I took a loan out with my bank to finance this. Test drove it and drove great... AFM worked fine.. I did research on the AFM while i was shopping and understood that they might leak oil so I was always prepared to purchase the range afm delete to plug in.

Problem was, right after I purchased the vehicle it was leaking oil. So i called the Shop who took care of the oil change and all that stuff before i took possession of it and the shop advised that they just rebuilt the motor. He was surprised that the dealer did not tell me about the motor rebuilt.. Even after that, i was not all that angry, i figured that hey, i should have rebuilt motor with new pistons, rings and crank shaft and if i install the range then im good to go for 200,000 miles, LOL... Of course as soon as i thaught that, oil was all over bottom of car.. oil spraying all over down by the bell housing. couldnt keep drop in.. Called the mechanic who rebuilt motor and he towed it back. Told me he tore it apart and it was the rear seal and that he was using a protective sleeve to make sure this doesnt happen again. and he is going to drive it for a day or two to double check it... My worry is, that if this mechanic has not worked much on these, whos to say that he knows about the AFM lifters? he might not, and im afraid he installed just any old lifters in there... I could be wrong and im known to overthink things. But either way, im getting a range system withen next week.. hopefully i dont damage lifters in that little time if he did install them wrong.

As far as oil leak, hopefully it was just the seal, if not, hopefully with him driving it these next couple days it will show up someplace else..we will see...thanks again.

yankeeslover · May 17, 2017

update...spoke to mechanic this morning. he replaced main seal and plate...states after driving 30 miles its still alittle wet under there.. not pouring out, but wet.. he is gonna keep it until he finds where its coming from... He is not really sure where the oil is leaking from.