Oil Pressure Fluctuation??
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Senior User
Joined: Jun 2005
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From: Bethlehem, PA
Oil Pressure Fluctuation??
The oil pressure fluctuates on my truck. i could be driving and itll be in the normal position but after a while itll drop and or go back up. i replaced the oil pump and it still has this problem. could it be a faulty guage, or the sending unit???
Senior User
Joined: Jan 2005
Posts: 389
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From: Visalia, California
Ouch...this might be messy.
Sounds like you have a pressure leak somewhere. I had this same problem on my dearly departed GMC. The rear main crank bearing had been eaten into by thrust from end-play on the crank. As the engine warmed up and the oil thinned my pressure would drop, sometimes to the point where I had rocker chatter. Your problem might be the same type of thing.
I raised mine up, pulled the pan and removed the rear cap. You might do the same thing.
Hope this helps.
PS: Or it could be a faulty sending unit. You might test it first. It's cheaper.
I raised mine up, pulled the pan and removed the rear cap. You might do the same thing.
Hope this helps.
PS: Or it could be a faulty sending unit. You might test it first. It's cheaper.
Last edited by Mil1ion; Jun 24, 2005 at 02:23 PM.
Postmaster
Joined: Feb 2003
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Do any of the other guages (gas or temp) also fluctuate? If so it could be the instrument voltage regulator. The IVR is mounted to the back of the instrument panel. It controlls the power flowing through the guages and has a common connection to all 3. It connets to the printed circuit with a connection that looks like a 9V battery. Also check and clean the connections of the guage to the printed circuit. Look for any broken traces or other damage to the printed circuit traces.
It might be best to install a mechanical guage temporarily to check the accuracy of the dash guage. If the mechanical guage mimics the dash guage then look at the engine. If not then check the guage circuit.
It might be best to install a mechanical guage temporarily to check the accuracy of the dash guage. If the mechanical guage mimics the dash guage then look at the engine. If not then check the guage circuit.
New User
Joined: Jan 2008
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Sometimes little piece of crud get caught in the orifice & this cause a reduction of oil pressure.
Take the sending unit off and clean it out with varsol or lacquer thinner , then blow it out with a low amount of compressed air.
Dust off works well for this.
Take the sending unit off and clean it out with varsol or lacquer thinner , then blow it out with a low amount of compressed air.
Dust off works well for this.
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