1998 Passat, Oil Pressure Light When Hovering at 1600 RPM

Could be your oil pump going out. Hopefully, that's all it is. Worn bearings should not be occurring at only 83K miles.

What is the oil pressure at 2000rpm with hot engine. I mean run the engine for about 45minutes and then check it.

Some engines (I seem to remember an Audi I had once that did) have two oil pressure sensors--one for low engine speeds and one for high engine speeds. At a pre-set engine RPM (guess what speed?) the system would switch from the low to high sensor.

If the hot oil pressure is marginal then it is possible to have enough pressure to keep the low speed side happy, and the high speed happy when somewhat above the switch over point, but still have low enough to trigger the sensor right at the swtich point.

Keep in mind, I don't knwo if this is applicable to your vehicle!

I know I have one sensor, but I don't know if it has a dual aspect to it. I'll discuss with the mechanic.

Thanks!

PeterD wrote:

I've had two independent shops (one the dealer) check the pressure above, at, and below 2000. All pressures checked out fine on both occaisions.

Lost >What is the oil pressure at 2000rpm with hot engine. I mean run the engine

I thought about that, and discussed with the mechs... but if it was the oil pump, wouldn't I see fluctuations in oil pressure at variable RPMs... especially higher RPMs when the pressure needs are greater?

I get it EVERY time I hover at 1600. I've hovered at every 100 increments between 1000 and 2200 and I never get it at anything but 1600.

It's so odd...

Papa wrote:

Then perhaps your oil pressure sender and/or your oil pressure gauge (including the wiring to/from these devices) are defective. Did the shop do a comparison between their gauges and the car's gauges? Is your tachometer accurate? Could it be sticking?

ones sensor, one wire. make sure it has the correct sensor in it.

I have basically the same problem with my '94 Jetta. The only difference is that mine beeps at 1950 rpm. I hope somebody out there knows the answer for this.

Jim

"But since the light comes on at 1600 only, I'd want the pressure checked at

"A no load 1600rpm oil light could indicate worn bearings. The motors barely moving enough to provide pressure. And no load floats everything in the bearings."

I'm assuming you mean engine bearings? That might be a silly question, but I'm not a mechanic. Assuming it is engine bearings, why would it only be at

The shop is also theorizing about the sludge/pickup problem at the oil pickup that is common with 4-cyl engines. I can't stop thinking that if it is a sludge pickup problem, I would see the pressure problem at lower RPMs... like idle... and at a variety of RPMs... not just at 1600 on ONLY at 1600 (hovering there).

Thanks a lot for your thoughts. It has been very helpful... even though the mystery isn't solved yet. I'll make sure I follow-up with the group when (if) I get the solution.

Jim,

Have you gotten anywhere with this? I'm still troubleshoot>I have basically the same problem with my '94 Jetta. The only difference is >that mine

You can get the oil pan removed for 2 hours tops to check the pickup if it's a 2.8l V6

My 95 Jetta has a similar problem. I searched it on the internet. Someone mentioned that this problem is mentioned in the car manual. However I do not have one with me. Can someone help to verify it. Meanwhile I just ingnore the beeping and keep driving.

Lost > You can get the oil pan removed for 2 hours tops to check the pickup if it's > a 2.8l V6

I've gotten a little further on this, but still with no solution.

The wiring has been traced all the way back to the board. They did find one crimped section and spliced in new wire... no change. Problem still occurs.

They have driven the car and pressure checked at 1600 with and without the warning. They've recorded the pressures at the various RPMs as recommended by VW and all are within spec.

They are still speculating about oil pickup, oil pump, possibly engine bearings... but why would they seen guage pressures within spec?

The next recommendation is to switch out the sensor again. Apparently there are two different type sensors approved for this installation. I have the OEM original type. There is another that they state has "more tolerance."

They did learn that the sensor starts checking pressure at 1500. So, I'm getting the light at 1600-1650... right at the bottom edge of the sensor range.

I will check the owner's manual today again. All it says (from what I've seen) is that you are supposed to immediately stop the engine when the light occurs.

It's getting really annoying... and I think it's happening more frequently... like it's easier for it to occur.