Oil Pressure: Yes...NO?

ohekk · #1 (**permalink**) 04-29-2003, 05:44 PM

Ok Not Cobra related:

Wife's 98 Durango 3.9 V8 86K miles:

Oil pressure is normal (40-60 PSI) then intermittently ( every 5-10 minutes) drops to ZERO! and the "Check Gauges" light gos on. Then, after a few seconds/minutes it jumps right back up to normal.

I've tried the obvious:

Check oil level
Changed the oil & filter
Replaced the sending unit and
checked connections
even tried running "engine flush" and changing the oil again

Though I haven't confirmed with an alternate gauge, it doesn't act like a total loss of pressure in that the lifters don't collapse and start to clatter.

Any ideas?

Plugged Pick up screen?
defective guage?
Oil pump? (it either works or doesn't...right?)

I'm praying for an inexpensive remedy!

PS> my brother suggested putting a piece of black electrical tape over the gauge and warning light!

Cobra20646 · #2 (**permalink**) 04-29-2003, 08:05 PM

Well your on the right track by thinking about hooking up a known good mechanical gauge and watch that along with the electrical one (if you can hook both of them up it would give you a definite answer).

Try that first. At least you'll know for sure what your problem is.... bad gauge or oil pressure problem. And if you go so far as to drop the pan to look at the pick-up, I'd change the pump at that time anyway..... isn't a whole lot more stuff in there that would cause a loss of pressure like your reporting.

Rick Parker · #3 (**permalink**) 04-29-2003, 11:21 PM

Sounds like an electrical issue, perhaps something to do with voltage stabilizer or something similar. Have the codes pulled by a technician and anylize them. Do any other gauges act up when this happens, any other readings fluctuate such as fuel level????

Rick

ohekk · #4 (**permalink**) 04-30-2003, 04:49 AM

no other fluctuating gauges or electrical problems noted.

is this something that can be diagnosed from the computer?

Cobra20646 · #5 (**permalink**) 04-30-2003, 06:10 AM

My guess is that whatever is causing the gauge to read zero, (assuming we still have normal oil pressure) is also causing the check engine light to come on, and also will place a OBD code in the computer. These computers are great for helping diagnose problems, but they are only as smart as the info that is fed into them.

Go to the source.... check the pressure first with a good gauge. If you start driving it around to shops to have the codes pulled, you "could" be doing additional damage to the engine.

- Jim -

Mr.Fixit · #6 (**permalink**) 04-30-2003, 08:33 AM

Put a mech oil pressure gauge on it.