'89 chevy K5 blazer ...5.7 L V8..just changed out the oil pump with a new GM replacement part..the average pressure is between 30-40 and the needles pegging 55-60psi..any ideas??
- posted
16 years ago
too high oil pressure after pump change???
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- posted
16 years ago
You're going to have to be more clear with that description. How do you know the average pressure is 30-40psi? What do you mean by peggin 55-60psi?
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- posted
16 years ago
the owners manual list average running oil pressure to be between 30-40psi. When i first started it ,the guage read between 55-60psi..The guage max pressure is 60psi..When giving it gas, it pegs off the scale.. Otherthan the gauge reading it seems to be running fine.
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16 years ago
Startup cold oil presure is NOT "running" oil pressure. The running pressure is based on a warmed-up engine, with the oil hot. The oil itself plays a part in this, with new oil running a slightly higher pressure than old.
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- posted
16 years ago
While everyone else is arguing about how your question is worded, lets try to fix your problem. First of all I am guessing that you changed this pump because of low oil pressure? Whenever I've put a new pump in an engine I've always taken it apart first and cleaned it. I put a new pump in an oval track engine once and blew the filter apart, it seems they didn't clean the pump good when they put it together. The problem that I always found is that the relief valve is stuck closed. This will not allow the pressure to bypass if it is too high.
The bad news is you will have to pull the oil pan again. Pull the oil pump off, drive out the little pin that holds the washer and spring in. You then will have to get the plunger out that may be stuck, I found that sometimes it is easier to "push" a little from the gear side that you get to by taking the four (or five) bolts out. Sometimes I found it helpful to blow a little air at it, but make sure you do it in a box or something so you don't have parts blowing where you can't find them.
Clean everything up with brake cleaner (or equivalent) put a little light oil on the plunger and make sure it works freely in and out of the hole. Reassemble and install in the engine.
This should fix the problem, it is too bad you have to do all this to new parts, but I do it every time I put in a new oil pump because of the problems I experienced.