Oil pressure increase with RPM's
 

1991

Any thoughts on this one. When idling, my oil pressure gauge reads about 40 PSI. When I increase the RPMs or while driving the pressure goes to about 70 PSI or higher. Ideas why the fluctuating pressure? oil level is fine.

Re: Oil pressure increase with RPM's
 

Oil Pressure Sensor Dash Gauge probably is the issue. Although I think on my 90' I have the same readings with the idle half way and hot near 65 or 70.....I know I replaced that Oil Pressure Sensor Dash Gauge one time on another 90' (the high oil pressure was pinned at 80) and the problem was cured.

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Engine Lubrication System Functional Discussion

Re: Oil pressure increase with RPM's
 

oil pressure will go up as rpm goes up

Re: Oil pressure increase with RPM's
 

True but LT5 oil senders can go bad. Best way is to compare your gauge to a known good gauge.

Re: Oil pressure increase with RPM's
 

On my L98 oil pressure is about 3-4 psi at idle, then goes up with rpms.

Ok, on the LT5 if the oil senders are bad; where would you hookup the test gauge?

Re: Oil pressure increase with RPM's
 

Both my 91 & 93 do the same after warmed up, while cold they both read to the high side. I just replaced the one on the 93 last summer was always reading low.

Re: Oil pressure increase with RPM's
 

Just remove the Oil Pressure Dash Gauge Sensor from the top of the Oil Filter Adapter and using whatever thread adapter you need for your test gauge with same thread as Oil Pressure Dash Gauge Sensor.

That will verify you actually have the correct oil pressure and your Oil Pump and Oil Pressure Regulating Valve are both working properly.

Now....it could (but rarely) be the Cluster (gauge) giving you erroneous oil pressure readings but I have never heard that happen before.

See Post #18 Engine Lubrication System Functional Discussion

Re: Oil pressure increase with RPM's
 

My 95 had a low reading from the day I bought it about three years ago.

I checked the sending unit and the top part of the unit fell off in my hand when I reached down to check the connection.

I'm surprised it was still working as lose as it was from the base of the unit. It would read a little low, cold but never reached correct pressure when warm.

I changed the sending unit and now it works great, much to my relief.

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