stevedaniel

Have learned a lot from previous posts re: these sensors + alarm. The car is a great 155k one-owner, properly maintained bought for next-to-nothing. That d*** alarm goes off at 2,000+ rpm. Pressure gauge works perfectly, car has no valve noises etc. Just that darn buzzer. Have tried grounding wire connections, isolated to the one wire on the two-connector (other wire to pressure gauge is working). Now the problem: replacing that 2 wire sensor is very difficult. Its not accessible on the back side of the brass block. Is there a way to kill that darn buzzer? I do not care about the "warning" lights-- will put tape over it if that's what it takes.
Have had several old Audi's, and this is one of the nicest. Thank you in advance for any help!

Rusty Spokes

If the buzzer is sounding off at 2000rpm+ you may have a defective high speed oil pressure switch. It works exactly the opposite of the other switch in the oil pressure sending unit. You have two switches..double check. Fooling around with the switch going to the oil pressure sending "can" visible at the rear of the holder in the picture above will not solve your problem.

The high speed switch ( could be part number 056919081 white in color) is an open circuit then closes to ground at about 1.8bar. If you ground that high speed switch wire it should kill the problem. If you ground the other low speed oil switch you will get an alarm..It is supposed to be an open circuit when the engine is running at anything above .8bar and grounded when the engine makes less than .8bar oil pressure.

You may have a red 078919081C 2.5bar high speed switch in there. That is okay. If you use light weight oils in the engine it may trigger an alarm. If so, use the 1.8bar switch.

stevedaniel

I have examined the two sensors and chose not to try and replace either or both-- they are harder than I want to try and get to, and from reading other posts the fault may lie in the dash circuits. The car is 155k miles, one previous owner and shows great oil pressure on the gauge. So, I tackled the cluster instead. Not able to determine exactly what is the buzzer, I opted to take out the two warning bulbs (red and yellow). That seems to have done the trick! Audi overdid it with redundant warnings, buzzers and lights. I have coolant temp, oil temp, oil pressure and check engine lights and that's enough for me. (Hey, its an awesome $500 car!!) Its ordinary for me to check all the other car issues: brakes, stop lights etc and I do not need a car yelling at me. If something goes wrong say at 2400 rpm, that's 40 rpm's per second, and its faster than my 71 yr old reactions can stop the rotations. From the old days, I thought 'idiot lights' were idiotic!

jda

This is interesting. If I run my 1993 100S V6 C4 longer than 15 minutes and the water temperature achieves Normal nearly 1/2 - on the gauge.

The Oil Pressure lamp comes on with the beeping. And here's the part concerns (ha) me. At the same time as the Oil Can Light beeping and Blinking (or whatever it does) Beep.

I begin a stream of what I believe is BLOW BY down the highway that would have Bond (James. Bond. 007) green with envy.
These two events occur simultaneously like clockwork every time the car is driven a steady 15 minutes .
I have to believe either the rings ( odo stopped at 226K probably 233K on it) the rings or bores----something---is ovaling I do not know.

Short trip car par excellence.
Now I've just recently had a water pump and timing belt (and thermostat) Job done. (and done well well ) And I did notice when taking home after that service- I was well into 15 minutes- the temperature gauge was-in normal range- I started to see the smoke screen being laid down in the rear view mirror BUT the oil pressure buzzer/light had not come on..
So I am feeling hopeful something may have changed.


But what on earth could cause after 15 minutes running the oil light to begin to flash and beep and the blow by to come out the tail pipe. Only when warm!
(Oil Level in sump -Oil Pressure gauge reading- fine

Start the next day --or even an hour later- perfect fine- and this cycle starts all over. been doing it for five+ years! Great short trip work car best Ever! Ever!