All day my car had good oil pressure 20 psi or so at idle, then this afternoon, I started it up and I noticed when I pulled into a drive thru that my oil pressure was about 5psi, I mean just right above the red marks. What gives? engine sounds normal. I did a search and saw that it could probably be a bad oil pressure sensor? are they difficult to replace? Im going to drain the oil tomorrow and check for metal too. Any how to's on replacing the oil pressure sensor? where would I hook up a mechanical sensor?

 

the oil pressure sender is at the back of the block just at the rear of the intake.. It looks like a sideways canister with a wiring connection. I would replace it and see it that changes things. If you have a buddy that has a mechanical gauge that would be good also.

Most likely it is something simple like that, on the other hand if checking the senders doesn't work you could be on the way to a rebuild like I was.

 

Did you check the oil level?

 

The best way to know is to connect a mechanical gauge to the oil port just above the oil filter. A spun bearing can happen in a matter of a microsecond.
How many miles on the car? Has the engine ever been opened up?

 

Removing the oil sender requires a special deep socket. Be careful when tightening down as the pipe threads on this part are quite small. Use teflon paste on the threads. Getting any particle of tape in there could be trouble. - Good luck to you.

 

105K miles, engine never opened. When I started it up this morning, the oil guage had 40psi, then when it warmed up to ~180 degrees, 20psi, then after 10 more minutes of driving ~10psi. These are all at idle.
I found this picture of the oil pressure sensor, and holy smokes its dug in back there, I hope I can get it out without bending something. I hope its the sensor, but I have a feeling it's going to be something else.

 

You can get to the sensor with a short ratchet, extension and the special tool but I found it a little easier with a jointed ratchet. At least use one of those extensions that swivel 5 or 10 degrees on the end.

BTW, when I replaced my sender at 100k miles, the hot summer idle pressure went from 10 - 12 lbs to no less than 25. When the engine starts now the pressure gauge shows 65 lbs. It never went above 45 before the change. Shoebox mentioned in one of his messages how an old sender can become inaccurate. I thought I would take a chance, spend $30 for tool and sender to see if that could be my situation. You can imagine how that made my day when I spent 1/2 hour changing the thing, start the car and see oil pressure like I had a new engine. I watched the gauge like a hawk for the next hour. It finally went just under what looks to be 30 lbs at idle. This was on a hot summer day to boot.

 

where can i get the tool to remove the pressure guage? dealership? any auto store? part # by any chance?

 

Mine is the same, I have a built 355 and it sits at 6psi on a mechanical gauge. I have been driving/racing it for about 3K and its fine....mayeb it is just bc i have a cheap gauge hooked up? I am getting a autometer electric for Xmas.

Jay

 

Do you mean the sender? If so - Autozone, $5. Probably other parts places too.

 

yes the sender, sorry cool. thanks

 

Please tell us how you make out - really hoping you have the results I had with mine. Just a reminder to use low torque when installing the new sender. It would be a disaster to break the end fitting off. While buying the tool get yourself some teflon paste too. The tape is a risk of getting it in the system.

 

okay I'll let you guys know how it turns out, I bought the sensor and the tool, but I've been busy trying to find a new car and haven't replaced it yet. I'll try tomorrow.

 

I am going to try to do the replacement, I dont have teflon tape, but I have some Permatex high temp thread sealant, will that work ? thanks

 

well I replaced the sensor, the old one was broken, the plastic seperated from the metal, but it didn't matter, its doing the same thing with the new sensor. I started it up and oil pressure was ~55psi, then warmed up and was just over 20psi, but when I started to drive, it started to lose pressure; while moving it had 20-25psi. but when I stopped at a stop light it read almost 0psi. What do you guys think?