Oil pressure question?

[SMOKEDYA]

I have a 93 notch 5.0, so when i'm out driving it the oil pressure gauge reads high and sometimes only when i come to a stop and it idols down's it reads 0 pressure, but as soon as you touch the throttle it goes right back up thern back to 0 as soon as it idols down again. It dosent do this all the time tho, but it does do it most of the time and mostly when its warmed up to normal temp. So could it be the oil pump or just a falty sending unit or gauge? I have an bad leaking pan gasket but i always keep the oil toped off. Any ideas? I have all stock gauges and the block has about 130xxx BTW. peace


john

 

[HISSIN50]

I would check the sender connection to make sure it is tight and clean.

An aftermarket gauge would help you a lot - even if just toss it on there for a few days (leave it sitting on the pass seat or something).

Do you hear any weird noises when it reads 0?

Good luck.

 

[86bluecobra]

yah i would say sender aswell. My bro inlaws car does this aswell. never hear any top end noises so we assume that the gauge or sender is faulty.

 

[srothfuss]

As long as you don't hear any rod knock's while it reads 0PSI than you are OK. Try switching to a thicker oil as a temporary solution. Eventually, a better gauge will be required to moniter your engines vital signs.

 

[BlownFiveLiter]

My guess is right there with the others, that it's the sending unit. It's also possible that you have a bad ground, as my 95 does this exact same thing, but it's caused by a bad engine ground, since I have other issues as well.

 

[oldman]

My 93 kind of did the same thing. My original gage registered very low. Replaced sending unit. Now it's 3/4 the way up, and stays there. It may not be accurate, but it's consistant!!!

Randy

 

[vristang]

Maybe Hissin will remember better details than I can right now, but I thought there was a thread recently that talked about the different sending units used on Fox bodies and SN95s. It seemed that the 2 applications had the sending unit scales calibrated differently. It may be worth the time to run the part number on your current sending unit and make sure that both of you (STangGT1995 and SMOKEDYA), are using SN95 sending units, and not the Fox body units.

Maybe I am confused or way off base, but I thought I would bring it up.

jason

 

[69Rcode_Mach1]

Sending unit, mine is the same way. The POS drops off to zero and sometimes it is working properly.

 

[BlownFiveLiter]

Mine's definitely the stocker. It's been good until around 99k miles, and I've had the car for almost 7 years, and 80k miles of its life.

 

[1988WHTGT]

Mine would drop to zero everytime I would get on it....the wire that goes to the sending unit was just loose...clamped it down with some pliers for a tight fit and it was fine

 

[HISSIN50]

Jason - I remember what you are talking about. The fox sender is supposed to be somewhat calibrated with a few graduations (though the reading is still hysteretic). THe 94-95 sender is supposed to basically read somewhere near the middle, or if pressure drops below about 7 psi, it falls to zero.

Matt might have seen info along those lines on the 94-95 side too.

Adding an extra gauge is so stupid simple (It is tons easier on a fox than 94-95) that I would do just that.

If someone doesnt want the gauge inside the car permanently, it could be mounted under the hood (for reference while wrenching). See Jrichker's car for pics of an underhood oil pressure gauge.

Good luck.

 

[bsedwebt70-5.0]

get a real mechanical guage on there ASAP!!!!! Mine did EXACTLY the same thing and I put a mechanical guage on it with 112k - cold idle was 50lbs and as it warmed up it dropped to 8psi hot idle - NO knocking sounds or anything - plenty of power etc... I did not like that reading so the motor is out now and I was about to kill the cylinders -- the crank and rod bearings were worn to almost nothing and the crank was scored very badly - so bad that the machine shop would not turn it since they said it has a slight bend to it too! I got lucky and did not have to re-bore as the scratches did not get deep or into the ring area of the bore - just a quick hone job and new rings, bearings, stock crank from Motorsports and now I am making it a bit better with an E cam, intake, mild head porting, all new hoses, water pump, etc....

 

[SMOKEDYA]

Ok well thanks guy's , and from the sounds of it , it is the sending unit. And thats what i was thinking as well! peace






john