Oil pressure gauge

[brianmc]

Howdy, not long ago everything was working fine and then next thing I know, I look down and my oil pressure gauge is pinging on L. I could hear it over the radio. Frantically, I look for the nearest gas station to pull over and take a look. Upon inspection there were no knocking sounds from the engine, no sounds out of the ordinary at all, no leaks, everything seemed just like it did before I startered it up that day. So I drive home diagnosing it as a questionable gauge, I wasn't far from home either. On idle, the gauge hovers perfectly in the normal range, around 1k it's fine. As the rpms increase the gauge starts to go haywire bouncing back and fourth. Around 2500 rpm the gauge is dancing between just before L and the lower end of the normal range. There's no strange engine noises, nothing out of the ordinary but this damn gauge going nuts. All other gauges are fine.

The gauge seems to act up more as the temperature gets colder also. Had the oil changed not 1500 miles ago and everything checked out. Has anyone had a similar problem?

 

[Maniak]

First thing.. That gauge isn't really a gauge.. Its an analog idiot light. It reads normal pressure at pressures above 5psi and low under 5psi.

There is a thread in the usefuel thread forum about installing a real oil pressure gauge. Basically, it is a quick mod to the back of the cluster and changing the sending unit.

With that out of the way, If you were at < 5psi oil pressure the 4.0 motor would be very loud.

Your first sentence

Howdy, not long ago everything was working fine and then next thing I know, I look down and my oil pressure gauge is pinging on L. I could hear it over the radio.

confuses me though. Were you really hearing the motor make noise?

If you are hearing things then you may really have no/low oil pressure which is very bad. It make sure, you can pick up a cheap mechanical gauge and temporaily zip tie it to a winshield wiper. If you loose pressure you will be able to see it (even when driving).

If you really are loosing pressure, but only at the higher rpms etc and assuming your not low on oil, I'd suspect the pickup screen or oil pump itself.

~Mark

 

[FIND]

First thing.. That gauge isn't really a gauge.. Its an analog idiot light. It reads normal pressure at pressures above 5psi and low under 5psi.

There is a thread in the usefuel thread forum about installing a real oil pressure gauge. Basically, it is a quick mod to the back of the cluster and changing the sending unit.

With that out of the way, If you were at < 5psi oil pressure the 4.0 motor would be very loud.

Your first sentence confuses me though. Were you really hearing the motor make noise?

If you are hearing things then you may really have no/low oil pressure which is very bad. It make sure, you can pick up a cheap mechanical gauge and temporaily zip tie it to a winshield wiper. If you loose pressure you will be able to see it (even when driving).

If you really are loosing pressure, but only at the higher rpms etc and assuming your not low on oil, I'd suspect the pickup screen or oil pump itself.

~Mark

I would also get the valve covers off and check if it is full of sludge if you are losing oil pressure at higher RPMs.

 

[brianmc]

First thing.. That gauge isn't really a gauge.. Its an analog idiot light. It reads normal pressure at pressures above 5psi and low under 5psi.

There is a thread in the usefuel thread forum about installing a real oil pressure gauge. Basically, it is a quick mod to the back of the cluster and changing the sending unit.

With that out of the way, If you were at < 5psi oil pressure the 4.0 motor would be very loud.

Your first sentence confuses me though. Were you really hearing the motor make noise?

If you are hearing things then you may really have no/low oil pressure which is very bad. It make sure, you can pick up a cheap mechanical gauge and temporaily zip tie it to a winshield wiper. If you loose pressure you will be able to see it (even when driving).

If you really are loosing pressure, but only at the higher rpms etc and assuming your not low on oil, I'd suspect the pickup screen or oil pump itself.

~Mark

The motors no louder than it was before the problem began. The noise i could hear over the radio i meant was the pinging of the gauge reading L for short periods of time. not the motor, the motor never once made a strange noise. How do I install this mechanical gauge that I can zip tie to my windshield wiper?
Thanks

 

[Maniak]

The oil pressure sending unit is on the driver side of the vehicle, screwed into a fitting, sort of behind the power steering pump. It has 1 wire going to it.

You put a pan under it, take out the sending unit and put in the mechanical oil pressure fitting/line (it will leak while the old one is out). You can run the line for the oil pressure gauge between the frame/inner fenderwell, out the wheel well (above the tire) over the fender and then just zip tie it to the wiper and anywhere else to keep it from getting tangled in the tire etc.

You can use this kind.
http://www.harborfreight.com/engine-oil-pressure-test-kit-98949.html

or just buy a cheap mechanical gauge that would normally go in a gauge pod. Either will work for the short time your going to have it up there.

All you want to do is keep an eye on the oil pressure by looking at a real gauge to figure out if you have an oil pressure problem or an electrical issue.

Since your not hearing engine noise I'm leaning towards electrical. If the sending unit wire breaks/comes off the sending unit the gauge will read no oil pressure. If the gauge itself or the cluster is having issues it can also make the gauge read wrong.

~Mark

 

[brianmc]

Awesome, thanks. Helps a bunch