Hi I have a very dependable tuck..a 96 toyota t100 2wd with the v6 engine.. however I'm very worried when I see my oil pressure gauge drop very low at idle. But it raises to about halfway reading whith increased rpms....do I have a problem? Thanks!

Its located behind the distrubutor its pretty easy to get a

the dodge web site shows it. there,
as does the shop manual shows it.

Well it could be the sending unit for the gauge.
But odds are the oil pump or engine bearings are worn out.
As the engine warms up, the metal spaces expand and the oil gets thinner. The oil pressure drops some under normal conditions, but not more than 10 or 15psi. Normal idle pressure with the engine warmed up is probably 25psi.
You could check oil pressure with a mechanical gauge to make sure its not the sending unit.
Once the oil pressure starts staying below 20psi for long periods you'll start hearing noises.

You'll want to remove the electrical oil pressure gauge and check the oil pressure with a manual gauge to verify low oil pressure. If the oil pressure tests good with a manual gauge, then you either have a faulty oil pressure sender, or gauge in the dash (I rarely see faulty gauges). If the pressure is still low, suspect worn crankshaft bearings. There is also a possiblity that the screen to the oil pump is clogged. This can be visually checked by removing the oil pan and cleaned.

A symptom of a engine that is almost 20 years old perhaps 200k+ miles. Mine does the same thing. I don't know how accurate the dash gauge is ... but I haven't been worrying about it. I run 10w-30 year round. I've had the truck over 8 years and 120k miles ... still runs great and the oil pressure gauge works as you describe since I bought it. Unless you are sure you have serious bearing problems or whatever I'd just drive it.

Check your oil, I borrowed my mother in laws truck like this it had no oil pressure well it didn't have any oil. If you have oil you have a weak oil pump or your oil passages might be clogged up. You could also try running a thicker oil like a 10-40 instead of a 10w-30, or maybe add some oil honey something like that. Hope it's just low on oil that would be the easiest fix.

First, do not keep driving if the oil warning light is on or your oil pressure gauge has dropped. Stop the engine, let it sit for a few minutes, then check the oil level.
If the dipstick shows a full oil level, then low oil obviously isn't your problem. The oil pressure may be low because of a worn or broken oil pump, a plugged oil pickup screen in the engine's crankcase, possibly a plugged oil filter or excessive bearing wear. Or, the oil pressure may be fine but the oil pressure sending unit has failed. Further diagnosis will be required to determine what's wrong.
Perform electrical tests on oil pressure switch http://www.clarks-garage.com/shop-manual/elect-19.htm
Replace pressure switch as the cheapest means of repair to see if the lights go out .
The pressure switch will be located on the engine block.

I had the same problem with My jeep, when i took it in to a shop, they couldn't find any problems, , after about 5 shops and a ton of headaches from the low oil pressure warning, they found out that the gauge had gone bad, you may want to look into it as well.

hi ben
my answer would be yes i would wory about it...
Guages are put on vehicals for a reason not just for looks i would have the car hooked to a diagnostic center and checked even though the guage may be faulty but i wouldnt take a chance

The oil pressure sending unit is a sensor with an internal diaphragm, if the internal diaphragm is damaged , or the line to the diaphragm is blocked you can get this kind of fluctuation on the oil pressure gauge.

The oil pressure value must be read by installing a mechanical gauge near to the oil pressure switch and checking the pressure.

If pressure is ok, replace the sending unit. If there is a real pressure drop, check the oil pump.

If you still get fluctualtion after replacing the oil pressure sending unit, replace the oil pressure gauge.

Hi,

The only positive way to check if the oil pump is working and therefore there is correct oil pressure is to temporary install a non-electrical oil pressure gauge that uses a small copper tubing to sample the oil/pressure and drive a needle on the gauge. Depending on temperature, idle should register about 20+psi. Having done this and confirmed that indeed there is sufficient oil pressure then it may simply be a defective oil sending unit. Otherwise, no or low oil pressure at idle is an indicator that the engine needs to be opened up again.

Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards.

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