I put Mobile 1 Synthetic in on the last oil change - 00/20W. Not sure if it's related but when cold (I'm in Pittsburgh) I get no oil pressure on the guage and the warning light stays on for about 3 - 5 minutes after startup. Any ideas?
Bob

 

I use Mobil 1 5W-30 and have the same problem during start-up in really cold weather. I assume it's just a sensor problem. If there was really no oil pressure for 5 minutes the motor would definitely be making some bad noises. There's no real solution that I'm aware of, but of course, I don't know much...

MJC

 

Thanks, that's what my buddy thought that maybe since it's so thin that it's slipping down past the sensor so quickly that it's not registering.
Bob

 

That would worry me. Oil is essentially a hydraulic fluid and as long as it is confined and pumped, there will be pressure. Even water will have some pressure in your engine as long as things aren't so loose that it just pours out of the crank and cam bearings etc.

It may be a bad sensor but I would want to replace it just so when it does work it tells me close to the truth.

Note that most of our oil pressure guages are really analog idiot lights. They either show zero or a narrow range in the middle. They really don't show the true or even relative pressure except none or some. There is a fix on this website that makes it act like a real guage but if it is stock it just says yes/no pressure.

Having 0 would bother me, and the real idiot light being on wouild also worry me even more.

My 94 F250 with 460 runs Valvoine syn 10W30 and it always has some pressure just seconds after a cold start, and almost never an idiot light. I have started in in temps in the teens and had good pressure from the start.

In fact your pressure should be higher than normal while cold and decrease as it warms up, unless you have a bad sensor or maybe a clogged oil filter which prevents oil from making it into the rest of the engine. Don't know if that will show zero pressure, but I think it will.

Sorry I just get freaky when I see zero or low pressure. I always want to know for sure why it reads zero.

Jim Henderson

 

SDB, I would be REALLY careful about driving anything without oil pressure showing. Especially if the guage works afterwards. My oil pressure shows after about 2 seconds of the engine running, regardless of the temperature. "99 v-10, Valvo synthetic 10-30

 

Changed the oil and filter night before last with Mobile 1 5W/30W and it seams to have solved the problem but it's been warmer here the last couple of nights. It's supposed to get cold this weekend so I'll see. Thanx for the input men, maybe it was the oil filter Jim? We'll see, I'll let y'all know.
Bob

 

Well it got cold again and the problem recurred. I just picked up the new sensor today (the part numbers been changed so they said it has been improved?) and am going to insatll tonight so I'll see.
Bob

 

SDBob, the problem must be the sensor you are replacing. The engine would have fried by now. Good luck.

 

Don't kid yourself ! Get some real guages on the truck
You'll feel better

Rich

 

Thanks Forty, I did replace the sensor last night and it was ok this morning at about 20 degrees in Pittsburgh, but I am gonna take your advice and put in some real guages.
Signed,
Ford Man For Another day

 

What are you using for a oil filter
?

 

The one spec'd by Fram, I think it's PH2?
Bob

 

00/20 is a little thin for a truck.
Have you tried Mobil 1 5w30?
(if you really really want synthetic)

I'm hoping your truck is a gas engine.
-T

 

As posted above, I changed it to Mobile 1 5/30W.
Thanx