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Oil Pressure Gauge

8K views 10 replies 6 participants last post by  Sherlock 
#1 ·
Help....my oil pressure gauge is going bonkers. When I turn off the TB it stays at 75-80, then once started it goes way past 80. The oil was just changed 2 days ago and is fine now. It was acting up before the oil change. Once I remove the fuse to the instrument panel and start it and then put the fuse back in, the oil gauge goes back to 0 while off and to 40 once started. Of course that only lasts for 1-2 starts then it goes bonkers again. Is there an easy fix for this? If so what is it? Thanks.
 
#2 ·
Sounds like it is just the gauge since it shows pressure when the engine is off. However, I'm not a mechanic. Personally, I would have a mechanic check the engine oil pressure just to be sure, when replacing the gauge. They can do that by attaching a gauge to the oil pressure sending unit.
Looks like your military. Don't get taken advantage of. Have it fixed at home or from a trustworthy mechanic.
 
#3 ·
I will probably take it to the dealer, but I was just wondering if it was something I could do at home instead. I thought it might be a little sensor that needs replacing instead of the whole gauge. I'll have to let you all know for future reference.

I am in the United States Air Force, the dealer here is pretty decent most of the time. Thanks for your comments.
 
#4 ·
Here is my question. I just had my cluster replaced for the tach doing its clicking thing and since I have had it back the oil pressure is WAY up it was about 40 at idle now at about 60. So what is the pressure suppose to be on these things? Its about 75 when at full throttle where as before it would only get to about 55. Any ideas guys?
 
#5 ·
Mine always idled around 40 and would move up to around 52-53 while driving, that is until recently when it's messed up on me. From the other posts on other threads I read others have said about the same thing. You can always do a search on the main page for oil pressure and there's a post about it.
 
#6 ·
I don't know if there is any specific number because the pressure will vary due to oil weight, type and amount in the engine. I believe the gauge in the TB are there for a general purpose and not an exact reading. If your reading high I would be concerned though, you don't want too much pressure because you might blow gaskets.
Hopefully, a GM Tech with add to this thread.
 
#8 ·
From the GM technical overview description of the 4.2 I6

"As oil enters the pump, the eccentric design compresses the oil, then releases the oil at a regulated max pressure of 65 psi at 2,500 rpm, circulating 11
gallons per minute."

It definitely should not be reading 75 psi. Sounds to me like maybe the instrument cluster needs reprogramming, like it is not responding properly to the oil pressure signal.
 
#9 ·
my oil gauge reads about 42 lbs. @ idle then it barely moves. it mite go up one or two lines at freeway speeds. the one in my dodge works like an oil gauge should work. lots of movement between idle and freeway speeds. i cann't believe i have 42 lbs. of oil pressure at idle.
 
#10 ·
Thanks tblazed! Its good t o know that you can get answers here. But you would have thought they would have made sure the thing was working right when they put in the new cluser. All I am asking for is some good sense with the techs thats all. Next question? Will that reprogram fix the gas gauge that reads about 5 gallons to low? and my low gas light will not come on for nothing. The gauge was past E and still would not go on. Thanks again all.
 
#11 ·
I was getting worried about mine, I just changed my oil and the gauge barely moves. I maybe get 60lbs at WOT, probably closer to 55. Low 40s while cruising and high 30s while idling. I guess thats normal. Wish GM would put real gauges in performance vehicles. The oil pressure gauge in my silverado ss moved a lot more. iIgot at least 60lbs at WOT, sometimes close to 80lbs when it was real cold at WOT.
 
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