I have a 99 tahoe (5.7L) that seems to have low oil pressure. Once it is warmed up, the pressure drops to about 20 psi on the dash gauge, when it idles. It gets up to around 40 psi at cruising speeds. I dont think it was this low at idle in the past because I would have noticed it. Oil level is good. There are 115,000 miles on it and has been thoroughly maintained the whole life. Does anyone have experience with this? Should I worry?
99 tahoe oil pressure low?
- Thread starter dtubbs78
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Try changing the oil pressure sending unit first. Also if available check the oil pressure with an actual gauge after removing the old sending unit. Then after oil pressure is checked with a gauge install new sending unit. They do go bad.
clkelley
Moderator
Welcome to the neighborhood!
I agree with the above. But, I have also seen some of those 5.7's in the past that did that even with a new sending unit. I know a man that has been driving his like that for many years and it has always performed.
I agree with the above. But, I have also seen some of those 5.7's in the past that did that even with a new sending unit. I know a man that has been driving his like that for many years and it has always performed.
iangeideman
New Member
my 1995 does that, been driving it for 9 months, no problems
It was over a year ago my Tahoe oil pressure dropped to zero. The oil level was normal. There was no noise coming from the engine. No smoke, I was low on money so, I just drove it but keeping check on the oil level and listening for noise. I drove it for about 3 months. I connected a mechanical gauge to it and it showed the same as the dash gauge. I dropped the oil pan, and removed the oil pump and screen. The shaft coming from the distributor that drives the pump was removed. The nylon connector that connects the shaft to the oil pump had gotten hot and was crumbling, it was barely hanging on the shaft and probably was not allowing the oil pump to turn properly. I replaced the oil pump with a high volume pump and new screen. I got a new shaft that came with a metal connector that will probably never fail. Cleaned it all up slapped it back together, and now I have 180,000 miles and great oil pressure.No problems.*** Several members here stated that it was a waste of time to do what I did because I was just putting off the inevitable, that I was going to have to rebuild anyway. This was not the case...........These engines are indeed "like a rock".
My 95 does the same thing. When warn and stopped at a light the oil pressure drops to about 5-10 psi. Then the light come on. I agree with flatfoot, change the pump. I would not recommend a high volumn pump since it could suck the pan dry under high rpm or continuous high rpm. Then you will have oil starvation problems. If you use the recommended oil of 5w30, then a heavier oil fo 10w30 may be a cheaper option since pulling the pan is a pita if you still have ifs. have to drop the ifs or disconnect the motor mounts and raise the motor to remove the pan.
justimagination
Full Access Member
I would not be that concerned, all engines do not have the same oil pressure comparison. If you were dangerously low on oil pressure, you lifters would be rattling, then it's time to correct it. Just use the recommended oil 5w30, or you could step up to 10w30, I also recommend only AC filter. JMHO, good luck.
david g.
