1997 5.9L oil pressure

DCDodge · 06-09-2005, 03:55 PM

Just driving down the road today and noticed oil pressure gauge suddenly drop to 0. When accelerating, the gauge goes back up and then back down to 0 when driving at steady speeds. Also, in Park and I press accelerator, gauge goes up...until I let off the pedal, then goes back down to 0. What is going on?

1997 Ram 1500 SLT Club-Cab
4x4, 5.9L, LT285-75-16 Michelin's

Hyginkz · 06-09-2005, 05:53 PM

Now that sounds like a sending unit failure, eather that or your out of oil.

fredjacksonsan · 06-10-2005, 10:04 AM

Yeah, sending unit; unless you're getting dangerous noises from under the hood.

DCDodge · 06-10-2005, 01:50 PM

No bad noises and oil level is fine. Where, exactly, is the sending unit sensor under the hood?

fredjacksonsan · 06-10-2005, 02:02 PM

I think it's found at the rear of the intake manifold to the right side of the distributor.

sharter · 06-12-2005, 12:11 PM

Quote:

Originally Posted by fredjacksonsan

I think it's found at the rear of the intake manifold to the right side of the distributor.

To: fredjacksonsan. I have a '98 Dodge Ram with a fluctuating oil
pressure gauge. I wonder what it could be? The
sending unit or oil pump? I want to try to take the
sending unit out and install a hand held pressure
gauge to see if it fluctuates on it. What do you think
it could be?

Thanks,
Steve.

fredjacksonsan · 06-13-2005, 07:33 AM

Does it fluctuate between driving and idling, or does it fluctuate while the engine is at a steady speed?

sharter · 06-13-2005, 10:16 AM

I think it fluctuates between driving and idling. That is when I notice it. It drops sometimes to just below 40 and then goes back to about 50 or 60. Sometimes it does not change at all at idle. I noticed yesterday it did it when I put the brakes on.
Any clue will help. No noise from the engine. Should I worry or just let it be?
Thanks for the reply.
Steve.

sharter · 06-13-2005, 10:18 AM

Quote:

Originally Posted by sharter

I think it fluctuates between driving and idling. That is when I notice it. It drops sometimes to just below 40 and then goes back to about 50 or 60. Sometimes it does not change at all at idle. I noticed yesterday it did it when I put the brakes on.
Any clue will help. No noise from the engine. Should I worry or just let it be?
Thanks for the reply.
Steve.

Also I failed to mention that it has 175,000 + miles on the engine.

fredjacksonsan · 06-13-2005, 10:31 AM

With that many miles, some fluctuation may be expected. I've had both 318's and 360's (5.2/5.9) and after many miles they too had some fluctuation in the oil pressure, most notably at idle.

A new oil pump will likely solve the problem, and IMO certainly can't hurt if you intend to keep the vehicle.

fredjacksonsan · 06-13-2005, 10:32 AM

As long as it's steady while under load you should be ok. And 40psi at idle sounds like it's enough, but dont' quote me on that.

sharter · 06-13-2005, 01:49 PM

Thanks for the info on this. I think that I will eventully put a new oil pump on as I plan to keep it for a while. Like you said, it won,t hurt. I wonder if I should try using an oil for higher mileage?

fredjacksonsan · 06-13-2005, 01:50 PM

Can't go wrong with synthetic for your engine. Runs cooler, might give higher mpg.

sharter · 06-13-2005, 02:45 PM

Thanks. I will use the synthetic on next change. I need to get better gas mileage. I estimate at about 10 - 11 mpg. I would like to get some ideas as to make it better.
When using synthetic will I still go by the same weight of what it is now?

fredjacksonsan · 06-13-2005, 03:40 PM

Yup, same oil weight for sythetic as recommended by the manufacturer.

Is the inside of your tailpipe black and wet? If so, you might have a bad O2 sensor, which would cause your truck to run rich. With overdrive you should be getting a bit more mileage (unless you put on larger tires than stock)

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