92RSFivePointSlow

my oil pressure gets very high and bounces alot when the car idles. I believe this is causing it to idle rough. It doesn't happen all the time and I did a full tune up not too long ago. I just changed the filter thinking it was clogged and causing the problem. If my oil pump is failing wouldn't my presure read low, not high?

dimented24x7

iTrader: (2)

What does teh pressure read between? The ocillating pressure may be due to ocillating engine speed. Does the idle fluctuate? How does the car drive?

sellmanb

I'm assuming that you are getting these oil pressure numbers through a mechanical oil gauge, and not your sending unit in the dashboard?

philoldsmobile

my oil pressure sender has just gone funky, ever since i've had the car its sat at just over 30psi regardelss of engine speed / temp.

on a trip to france the other week, the pressure started to fluctuate, never dipping any lower, but occasionaly jumping to anywhere up to 60psi, even when idling hot.

the engine continued to run perfectly, so i carried on.

600 miles later, the guage just returned to normal - the car continues to run perfectly.

the consensus of opinnion is that the sender unit is starting to die, if it were a genuine oil pressure problem it would more likely drop off.

Don't trust thirdgen guages!!!

92RSFivePointSlow

thanks for the help. The rough idle turned out to be a spark plug wire that had come out of it's loom and got burnt on the header, I replaced it. The oil pressure guage still bounces around alot when the engine is idling steady, so I guess the sending unit is on it's way out. I've determined the two problems aren't related. Thanks again.

92rsbowtie

just hook up a mechanical gauge and find out your actual pressure cuzz these electric gauges are not accurate. theres a tap by the distributor, sending unit, and above the timing cover on most engines, in case you didn't know. my sending unit went out as well and the gauge did the same thing.

trans_am_ta_84

what he said.. my guage completely doesn't work for some reason, and i'll be buying a new guage. i know my oil pressure isn't 0 when i just rebuilt the motor and it's been at 0 for a month now and still not knockincg

sellmanb

Philsoldsmobile --

Sounds like your sending unit is grounding out on something, may want to follow the wire back and make sure it's not doing that. Also, your oil pressure should raise from 30 when accelerating.

92rsbowtie

its a very common problem for sending units to go out. i highly doubt its grounding on anything. my sending unit is out as well, and it does the same exact thing as yours philsoldsmobile.

philoldsmobile

i've done 40 000 miles in the car in 3 years, so i'm confident its fine!