Oil Pressure Issues
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Postmaster
Joined: Apr 2002
Posts: 3,613
Likes: 6
From: Coal country
Oil Pressure Issues
I have a rebuilt '86 460. Oil pressure is slightly high normal at idle when cold.
Once it heats up, it drops to very low at idle. If it idles for more than 5 minutes, the oil pressure continues to drop to dangeroulsy low (on the gauge) - but it never makes any noises indicative of low oil pressure. However, if I run it at 750 RPMs, the pressure picks right back up quickly to mid-normal range.
Normally, I would suspect a problem with the main bearings, but in my experience (none of it with 385s) the pressure wouldn't go back up, wouldn't go back up quickly, or wouldn't go back up very high.
I intend to replace the stock cam with an "rv" cam, should I go on ahead and replace the oil pump just to make sure? In the old FE I had, a high volume oil pump had a tendency to wipe rod bearings.
Is this characteristic of all high volume pumps, or is high volume pump a good idea in a 460?
Thanks for any and all input.
Once it heats up, it drops to very low at idle. If it idles for more than 5 minutes, the oil pressure continues to drop to dangeroulsy low (on the gauge) - but it never makes any noises indicative of low oil pressure. However, if I run it at 750 RPMs, the pressure picks right back up quickly to mid-normal range.
Normally, I would suspect a problem with the main bearings, but in my experience (none of it with 385s) the pressure wouldn't go back up, wouldn't go back up quickly, or wouldn't go back up very high.
I intend to replace the stock cam with an "rv" cam, should I go on ahead and replace the oil pump just to make sure? In the old FE I had, a high volume oil pump had a tendency to wipe rod bearings.
Is this characteristic of all high volume pumps, or is high volume pump a good idea in a 460?
Thanks for any and all input.
Elder User
Joined: Sep 2004
Posts: 500
Likes: 0
From: midwest
i would put a real gauge on it to see what its really at. mine use to idle at 5 psi till i replaced the bearings and pump. know it idles at 35 psi hot. i use a stock replacment pump so you dont have to worry about a bigger pan or other problems that can happen.
Freshman User
Joined: Jul 2004
Posts: 35
Likes: 0
From: SF bay area
You say the engine is rebuilt. Going with that I would change the pump. It sounds like a sticking or damaged oil pressure regulator valve spring. With these oil pumps located inside the pan, adjusting the pressure regulator isn't practical.
My .02
My .02
