Low Oil Pressure!

[critterCQB]

We were out all day saturday, and all was fine. On the way back to the marina, I looked down and was at like 5-8 psi. We made it back to the marina fine, no noises, smells, explosions(ha!), etc...

Sunday, I fired it up at my work to flush it out. I checked the guage, and I was back to 40 psi, nice! 15 minutes later, i was at 5-8 psi again(sh*t).

Oil level is right where it needs to be, no oil in the bilge either. Any clues?

Oh, it's an '86 Comp, PCM 350.

[DKJBama92Mariah]

First and cheaest guess, check the wiring leading to oil pressure sensor. Should be in the neigborhood of the oil filter.

Is this a ford 351 or chevy 350? I just can't remember whether PCM even sold a chevy 350 in '86. Way to tell: chevy had the distributor at the back, ford has it at the front.

[critterCQB]

It's definitely a Chevy. I worked at a marina, and we always said "Ford in Front" to distinguish between the 2. Really screwed us up, when the V-drives came out. It's an '86 Comp "Limited Edition". I think there was a choice for the Lt Ed's. I'll check the oil pressure sensor for sure, and the guage. Then, I'll really start to worry if that's not it! Thanks!

[hoosier skier]

I would think that with only 6 or 8 psi. oil press, the lifters would be very noisy and you would smell the residual oil burning under the valve covers. If you have a doubt about the gage or sender, unscrew the sender and screw in a mechanical gage & run the engine. You should be able to find a gage at autozone for under $30.00 . Hope this helps.

[DKJBama92Mariah]

I would think that with only 6 or 8 psi. oil press, the lifters would be very noisy and you would smell the residual oil burning under the valve covers. If you have a doubt about the gage or sender, unscrew the sender and screw in a mechanical gage & run the engine. You should be able to find a gage at autozone for under $30.00 . Hope this helps.

What he said

[critterCQB]

So I spoke to one of the mechanics at the dealer we got the comp from. He's thinking it's my oil pump. He vaguely told me where the censor is(on the block, above the transmission?), but where's my oil pump?Any help would be super awesome.

[Pdowling1]

Smell your oil. It isn't uncommon for raw fuel to run down the intake when the engine if not running, and dilute the oil. The fix is to adjust the float level in the carburetor. Be very suspicious if the oil level seems to rise with use.

[KenG]

Your oil pump is located inside the oil pan.

You did not happen to have the distributor removed prior to this problem did you?

[critterCQB]

Nope, distributor hasn't moved. Now, at the risk of sounding like and idiot, and please forgive my ignorance, but does this mean I'm going to have to drop my oil pan to get to my oil pump? If that's the case, I'm in WAY over my head. This just keeps getting better and better...

[Seabeejamie]

You definitely would have to drop the oil pan to replace the pump....I would start with an external oil gage before I did that though...make sure that is the TRUE reading. 6-8 psi at idle is not bad for a Chevy...Ford either for that matter. As long as that oil pressure comes up when you load it, you will be alright. It is a sign of engine wear, but as long as you don't have any lifter noise you should be able to get several more seasons out of it.

[critterCQB]

Ok, I picked up a sunpro oil pressure gauge today. $18 not too bad. I'm gonna check the oil, see if it smells like gas, then fire it up. If I'm still having the same issue, I'll hook up the new gauge and see. Wish me luck...

[critterCQB]

Great success! When I located the sending unit on top of the block, it had oil running out of the top! I pulled it out, which was a bit time consuming, but I got the manual gauge screwed in there. I fired it up, and I was back to 38 PSI! Now I dunno if I wanna replace the sending unit, or just replace the gauge with the sunpro. I should prolly replace the sending unit... AWESOME:D

[DKJBama92Mariah]

Great success! When I located the sending unit on top of the block, it had oil running out of the top! I pulled it out, which was a bit time consuming, but I got the manual gauge screwed in there. I fired it up, and I was back to 38 PSI! Now I dunno if I wanna replace the sending unit, or just replace the gauge with the sunpro. I should prolly replace the sending unit... AWESOME:D

Good deal. Feels good don't it?

[critterCQB]

Hell yes it does :cool:

[kingwoodlee]

My 99 Suburban did the same thing one day while driving down the beltway. I pulled over, checked the level, smelled everything, and made the decision to continue on. Once home, I bought a new sending unit and that fixed it. So, sending units do and can go out. However, my 88 comp still has the original sending unit at 20 years old. Go figure.