ToniJ1960

Sitting at a stoplight car in drive the oil pressure started dropping, it was at 60 then 58 56 54 52 50 487 46 44 42 40 38, steadily everey few seconds. I put it in park and it came back up over 50.

I just had oil changed and new filter. It could be low I guess, going to double check it.

Could the oil filter cause anything like this?

I know 60 at idle sounds high but thats what it always has shown. Now if its showing 60 and its really 50, then what is it when it shows 38, thats why it bothered me I never saw it that low since I bought the car, and it was still dropping.

Also, I never had the car when it was full blast summer, so maybe its related to that.

My other car shows 44 at idle, and its supposed to have a 60 pound relief valve although when its cold it will go over 60 with rpms. If it drops below 36 it always means its low or getting really hot (aftermarket oil pressure gauge).

Oil temp was showing 201

bjankuski

It is normal, at idle with warm oil the pressure will drop. It sounds to me like your pressure is fine. Rule of thumb is 10 PSI for every 1000 RPM.

ToniJ1960

Its just that I was always told it should be at least 25 at idle and if its reading a little high, showing over 60 at idle, it could be close to that when it shows 36. I dont really even know how far it will keep dropping.

Oil temperature of 201 its seen plenty and didnt see it do that then. But maybe the filter was due to be changed?

Tom400CFI

So at idle, you'd be fine w/8 PSI or so. I think that you're worrying about stuff that doesn't need worrying about.

ToniJ1960

maybe, I just never saw it do that before and who knows how far it will keep dropping?

Tom400CFI

Test it and find out . It shouldn't "keep dropping". It should drop to a point where the "leakage" no longer exceeds the flow, then pressure should stabilize. If it doesn't, I'd start testing/checking your oil pressure gauge circuit.

ToniJ1960

Today saw it dropping but held steady once ikt hit 50. I saw 38 yesterday the way it was dropping so fast made me worry hopefully its just me being a worry wart.

Tom400CFI

Assuming the oil was warm in both cases, I'd say your oil sending unit or circuit needs some attention. Shouldn't be seeing 12 PSI variation one day to the next...provided the conditions were the same.

WVZR-1

The FSM I believe will tell you to expect 30 - 40PSI at speeds of 35 - 45 MPH, they don't relate it to engine RPMs. The gauge is a 0 - 90 Ohms. 0 - 3 at sending unit engine off, 3 - 90 running. 90 Ohms should peg the dash unit if you wanted to check it.

The cluster warnings are net for 4 psi below 800 Rpm and below 25 at 4000 RPM.