Oil pressure beeping light - help?

[12valvestallion]

Hey ya'll. First off, yes I've searched and read quite a few threads on the whole MK3 (2.0) oil pressure light beeping issue. Lots of good information on here, but I've sorta hit a snag.

I have a 98 2.0 Jetta, which started beeping about 1.5 oil changes ago. It started very infrequent and has become more frequent. the oil pressure switches (both) have been replaced, the oil has been changed to 15W30, the oil filter is a VW one, and my oil pan is not dented. I recently had my shop check out the car for this issue and the oil pressure was fine across the board (couple PSI over spec). I have taken the wire off to make sure the cluster is working consistently, and yup, she beeps like mad once I take the wire off, but doesn't beep (like mad, at least) when its on.

Most recent event that has me scratching my head, is that I put some lucas oil stabilizer in (about 3/4 quart) and for a while I thought it had actually solved it. But then it still beeped, just a lot less frequent and it beeped while going slow speeds, whereas before it would beep more typically at highway speeds.

My original hunch was either a) oil pump intake area has cloggage, or b) oil pump is 'going' bad (but I'm not aware of an oil pump 'going' bad, I thought they just work, or they don't). But now, I'm confused. Why would an oil stabilizer (which thickens the oil, I believe) make the error LESS frequent, if the issue is cloggage or oil pump failure?

Unfortunately, I do NOT have a garage nor tools, so doing anything besides popping the hood basically makes me take the car to a mechanic, and my mechanic isn't exactly cheap. I do not want to just take a stab at 'well maybe its your oil pump' or 'maybe its your cluster' (which I doubt) without having a good reason.

So what do I do?

1. Just take the car to the mechanic, let them know that I put in the oil stabilizer, and say 'do your diagnostic' and see what they say? My bet is, they will say 'well you're running at spec, so we could either replace your oil pump/cluster, or we leave it as is' to which I will say 'leave it as is' because my money doesn't just grow on trees. Back at square one.

2. Take the car to the mechanic, and specifically let them know that I would like them to drop the oil pan, clean the baffle and the oil pump intake area, and then call me. If there was a bunch of crap in there, problem solved (although I'm not sure why my car would be running at spec PSI just a few weeks ago). If there wasn't a bunch of crap, I'm back at square one sort of (but at least I know my oil pan/baffle/pump is clean).

3. Put in more lucas oil stabilizer

4. Ground out the wire to the high-pressure oil switch, and get a oil pressure gauge to replace it.


Feedback is greatly appreciated.

[Anony00GT]

I'd have a shop do the diagnosis if you're not willing to do it yourself. Then trust their diagnosis, and hold them to the repair.

The first step is to get a mechanical gauge on there and watch the pressure. You may have an oil pump problem, or you may have worn mains, resulting in low pressure. It might just be a loose connection at one of the sensors or a broken wire somewhere too. Did you replace the sensors with the correct part number OE sensors (installed in the correct locations), or cheap aftermarket parts?

You could ground the sensor and put a gauge on it I suppose, but I've never been a fan of in-car oil pressure gauges. They really make a big mess when that little plastic hose breaks.

[12valvestallion]

I'd have a shop do the diagnosis if you're not willing to do it yourself. Then trust their diagnosis, and hold them to the repair.

The first step is to get a mechanical gauge on there and watch the pressure. You may have an oil pump problem, or you may have worn mains, resulting in low pressure. It might just be a loose connection at one of the sensors or a broken wire somewhere too. Did you replace the sensors with the correct part number OE sensors (installed in the correct locations), or cheap aftermarket parts?

You could ground the sensor and put a gauge on it I suppose, but I've never been a fan of in-car oil pressure gauges. They really make a big mess when that little plastic hose breaks.

Thanks!

What do yo mean by trust their diagnosis? If they say "your oil pressure is fine" then my engine blows, they owe me a new engine? I'm confused.

Yes, they put a mechanical gauge on it and it read fine last time, so i'll have them try that again.

I'll also have them double verify that they put the right switches in (they replaced the oil pressure switches, not me). I would have to assume they did the right ones, as this is a pretty specialized VW shop, but I guess it doesn't hurt to triple check. Especially if they now owe me a refund for $100 or so in diagnostics because of a sensor that was incorrect

It seems like the easy fixes would have been caught by the shop, but maybe not. Its so frustrating not having tools.

Thanks for the opinion on in-car oil gauge. I'd prefer not to go that route.

[Anony00GT]

I mean if they say their repair will fix your issue, hold them to it. But it sounds like they replaced the sensors in an attempt to fix it already, and failed.

The fact that the Lucas changed the behavior makes me think you've got an actual problem going on, not just a sensor. It could be coincidence though if there is a wiring issue with the sensors.

They should install a temporary mechanical gauge and drive the car, watch pressure. Without numbers it's tough to know what they're seeing, I've never seen an oil pressure gauge that said "good" or "in spec"

[12valvestallion]

They did use a mechanical gauge....and the gauge said like 2-4 PSI over spec, across the board. And I'm running 15W40, not 15W30. my mistake.

[drobdog06]

Screw the Lucas crap. Get sea foam much better quality and useful for a variety of things.

[Glumrug]

Is there any sort of pattern you've noticed?

Does it happen when hot/cold, on an incline? Low/high rpm? etc, etc

Is your oil full, and is the orange dip stick tube funnel intact?

15w30 should be fine unless its insanely hot there. The Lucas oil treatment thickens oil, so if that helps something is going on.

Oil pumps can go bad, if the gears wear enough pressure will drop. There are wear measurements in the Bentley, but unfortunately most of the cost is likely to be labor anyway. In that case if you have it out, and you don't know how old it is, it might as well be replaced. (IMO anyway)

[mikey699]

My best bet is your oil pump is going if your car is low like mine.
I guess i hit a nice bump which crushed my oil pan which cracked my oil pump which gave me a beeping sound more frequently so i suggest taking a look as the sound does get annoying

[jegas6228]

is it doing it more at idle, or part throttle? you never mentioned mileage of the motor, you could have bearing clearance issues.... like they are wore out