What are the differences between the "old" and "new" oil pumps?
#1
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In reading some threads, people refer to the old and the newer style oil pumps, with the change being somewhere around 2001. What are the actual differences in the pumps?
I dissected 3 pumps recently. A "mystery" pump that looked virtually brand new, the pump off my 03 LQ9, and a brand new pump.
They all looked pretty much identical inside, except that the new pump had lousy looking machining, so I returned it and decided to port my "mystery" pump and install it.
After reading about the old pumps being a poor design, I got curious and pulled my mystery pump back off the motor I'm building, and I see that it's stamped with a 97 build date. So, I apparently have one of the old style pumps, but after having been inside of all 3 pumps, I can't say I ever identified any differences. Does anybody know what they are?
I dissected 3 pumps recently. A "mystery" pump that looked virtually brand new, the pump off my 03 LQ9, and a brand new pump.
They all looked pretty much identical inside, except that the new pump had lousy looking machining, so I returned it and decided to port my "mystery" pump and install it.
After reading about the old pumps being a poor design, I got curious and pulled my mystery pump back off the motor I'm building, and I see that it's stamped with a 97 build date. So, I apparently have one of the old style pumps, but after having been inside of all 3 pumps, I can't say I ever identified any differences. Does anybody know what they are?
#3
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If I remember correctly most of it was with the relief valve. I could be wrong but I do know the later pumps had issues with that valve sticking open specifically on the trucks. (2001-2006 ish? ) wish I could remember the years but there was a gm TSB for it and I saw a few 5.3l trucks that did this on cold mornings.