Oli Pressure Jumps when Cold?

[NFCStang]

My oil pressure gauge jumps up and down when I start the car when it is cold outside(40 F or less). It will start at the normal point on the gauge and then drop to nothing and then jump back up again. Once the car warms up to operating temp it's fine. But for the first few couple of minutes I really baby it (under 3K RPMs).

It has never done then when it's warm out.

Anybody have any ideas? Could it be a bad sender or pump or is it just because it's cold out.

 

[Route666]

I think it could be the cold oil surging.

 

[mity2]

Oil thickens when cold. Not so much on synthetic oil, but more so on mineral oil. this will create oil pressure to go up(obviously)this was very prominent on my 99 Cougar, which I had autometer Oil pressure gauge, which was very accurate. So that could be why.

just for the record, my oil press. gauge does not move at all-cold or hot.

 

[02MGGT]

I believe the oil pressure gauge in the Mustang is an ON/OFF switch. In other words, it does not fluctuate with actual changes in oil pressure. It's absurd, but I guess all these little cost-cutting measures add up in the end...

If it does fluctuate, you have a problem... Hopefully it is just instrumentation.

 

[Ruffrider]

Mine doesn't do it in cold weather.... but than again i live in FL

 

[NFCStang]

I believe the oil pressure gauge in the Mustang is an ON/OFF switch. In other words, it does not fluctuate with actual changes in oil pressure. It's absurd, but I guess all these little cost-cutting measures add up in the end...

If it does fluctuate, you have a problem... Hopefully it is just instrumentation.

I'd like to think it's the sender or something along that line. Like I said, when the temp is above 40F there is no problem, but once the temp drops; that's when it rears its ugly head. Once the car warms up (2-3 minutes) it goes back to normal. Oil Level is good and there are no leaks.

Runs good, doesn't burn oil. Can't figure it out.

 

[Wiredawg1]

Replace the oil pressure sending unit. It's probably faulty, and not really expensive..

 

[2000GTnoExtras]

Did this work? I am having this problem and it's bugging the heck out of me.

Thanks!

 

[triggz]

if youre still having this problem and your car still runs without dumping 5qts a day into it, its just the sender. it only takes a few seconds w/ no oil psi to destroy a motor.

i got an autometer oil psi gauge and its around 75psi on a cold crank...you should never come close to turning 'off' the oil gauge.

 

[2000GTnoExtras]

Is this listed as OIL PRESSURE SWITCH?

Like OP80941 on http://autozone.com

 

[stang09er]

I live in the detroit area and my stang does this also. It started as soon as the cold weather hit. my pressure is totally gone for about 30 secs-60 secs....i found by blippin' the throttle, the pressure goes back to normal. i use synthetic so i don't think it has anything to do with the oil geling up. it has been going on for the past couple months and i haven't run into any problems...

 

[2000GTnoExtras]

I'm going to replace my Oil Pressure Switch soon. Gonna try reseating the "wiring assembly" on the sending switch first though.

http://www.autozone.com/servlet/UiB..._us/0900823d/80/1d/aa/34/0900823d801daa34.jsp

 

[TripleBlk]

just for the record, my oil press. gauge does not move at all-cold or hot.

LOL, mine neither ! It hasn't fluctuated in 5 years ! I need to look at the needle and see whether it's painted on or not.

 

[Mustang_chic]

LOL, mine neither ! It hasn't fluctuated in 5 years ! I need to look at the needle and see whether it's painted on or not.

that's pretty pitiful!