http://www.gowesty.com/library_article.php?id=810), and looking elsewhere, I haven't quite found a match for my symptoms.
I have an '88 Westfaila, with 20W50 oil that I put in in November, and some filter they had in a package deal sale at AutoZone - might have be an STP. My oil level is fine.
The buzzer comes on and the light starts flashing only under the following conditions:
(1) It's hot outside, or at least pretty warm, and
(2) I've been driving at highway speeds for at least
about 10 minutes, and
(3) I decelerate (usually getting off the highway), and the
engine RPM's are below about 2000.
If I raise the RPM's above about 2000, the light and buzzer go off, then come on again if the RPM's drop back down again. This goes on for 5 or 10 minutes, after which it will usually get tired of me ignoring it and the buzzer and light will go off.
The strange part is, the GoWesty description, and other, similar descriptions, say that the buzzer can only come on ABOVE about 2000 RPM. Mine only comes on only BELOW about 2000 RPM.
It may or may not be significant that, about 8 years ago, the van was in a serious front-end accident. The shop that did the repairs was less than thorough, and I still occasionally discover things that were mis-wired or installed poorly. I've also had some major engine work done in the last year or so by a shop that has turned out to be less than competent (but what they lack in competence they make up for in high prices), so there is at least some possibility of miswiring (or other issues) there, too.
So: any ideas what's up?
I've read that many people feel that using anything other than Mann or Mahle filters can cause the buzzer and light, but I've read others that think that using them is just masking a problem that has some other cause. Still, maybe I should just change the oil and try a German filter.
I could try replacing the two oil pressure switches. From what I've read this sounds fairly difficult (or expensive, if I have a shop do it) for something that may or may not be the problem, but perhaps that's the way to go.
I'm sort of thinking (but not at all sure) that I don't have a real oil pressure problem, since this has been going on for a while, and the engine hasn't exploded yet.
And in any case, there's the oddity of my light and buzzer only coming on below 2000 RPM, when all the literature I can find says the buzzer only comes on above 2000 RPM.
I've had the problem occasionally in the past, but I didn't pay enough attention to know if the symptoms were identical. At least once it was a loose wire on one of the pressure sensors, but I don't think that's the case this time - the behavior seems too predictable, and not random enough for a loose wire. I've used mostly Fram, Mann, and Mahle filters in the past, but occasionally something else, usually (as far as I remember) without trouble.
Thank you for any advice!
- Steven Sittser
