Hello Scotty, my 2007 GMC Yukon 5.3L is needing a lifter change. The mechanic isn't sure what type of lifter I should buy or how many, until he opens the motor. I want to know what type I should get so i can order them ahead of time and have them ready for when he opens the motor they're ready. I have seen that this vehicles have two types of lifters some short and some longer with a type of spring. How many lifters per cylinder and what types. My trucks complete description is 2007 GMC Yukon 2WD 8 Cylinders 0 5.3L FI FFV OHV 325CID. I don't understand what the nomenclature at the end of the description means but I want to know if this is crucial to find out what type lifters I need. tank you very much for your time and all your wisdom for us regular folks out here.
2007 was right about the time of cylinder deactivation and also the beginning of new generation of the Chevrolet Silverado/GMC Yukon. I am not 100% sure yours has it (the cutoff between the end of one generation and the beginning of another makes it hard for me to tell.) Anyhow, if it has cylinder deactivation the taller lifters with the spring are the cylinder deactivation ones, whereas the shorter ones are the standard ones. Cylinders 1, 4, 6, and 7 have the cylinder deactivation lifters. Each cylinder has 2 lifters (one for intake and one for exhaust). So 16 lifers total with 8 of them the cylinder deactivation ones. See link below:
As for the nomenclature:
- FFV = Flex Fuel
- OHV = overhead valve (aka pushrod engine)
- 325CID = 325 cubic inches displacement (which is ~5.3 L)
Do you know the RPO code? That can tell us the exact engine you have. I am thinking you have LY5, but we need to double check.
LY5 didn't support flex fuel. He would have an 'LMG' which uses AFM.
https://en.wikipedia.org/wiki/General_Motors_LS-based_small-block_engine#3.78_in._bore_blocks_(2005%E2%80%93present)
Thanks @MountainManJoe for that catch.
To tell us which engine you have, what is the 8th digit of your VIN?
see below:
I would not invest further money in to this poorly designed engine. It's known for oil consumption and other horrors.
If OP is determined to keep that vehicle and has the budget, he is better just deleting the AFM hardware and retuning the ECU.
I guess if he's determined. But I suspect he would be in deeper than the vehicle was worth.