oil pressure light/buzzer problem

[Patrick]

92TD jetta, two sending unit system (both new) on 84 engine installed last week. Low mileage engine (I have the donor car) with fresh bearings and oil pump. Shows lots of pressure on a guage screwed into the head. Eveything shows the way it should until full temp is reached. Then, when the revs drop to about 2250 (coming back into town) the light and buzzer come on. Downshift  (up come the revs) and they both go out, and will stay out most of the time even when idling. Other way to get the light out is to turn the key off/on. Just happens at a certain rpm when hot. Had a similar problem a while back with my wife's gas fox, went away by itself. What gives? I know I've got lots of pressure.....................

[jtanguay]

my dad had the same problem with his 91 golf gasser.  Turned out to be a faulty sensor!  I had the same problem while driving it.  Low rpm sensor came on, while driving it went away!  Plus the water pump was shot (pulley was wiggling a LOT) so it was replaced.  I didnt know they used aluminum for that..

I guess you could just live with the faulty sensor or disconnect it, as long as you have your oil pressure gauge and monitor it to make sure your engine isnt losing oil pres.

Anyone else have an opinion?

[fspGTD]

Your car has the "dynamic" oil pressure light.  There is some info on it in this thread you should check out:
http://www.vwdiesel.net/phpBB/viewtopic.php?t=21

[Patrick]

Thanks, I knew it was the dynamic oil pressure setup. Probably just a problem with the relay. Like I said, we screwed a manual guage in the head and found loads of pressure. HOw do I find the relay, just follow the harness?