Club 80-90 Forums

hi all,sorry but my head is spinning,been thru wiki,manuals,web search regards BUZZER OF DOOM,1.9td aaz , started last week,oil light and buzzer came on,(engine upto to temp),pulled over,ignition off,started up a few minutes later and all ok rest of day,in the days following it became more frequent,stop / start until it now comes on almost straight away first thing in the morning,(cold start 50 yards) ive put new sensors in,white and blue,also tried disconnecting white sensor,still oil and buzzer came on,tried the same with blue sensor and the buzzer and light still came on,tried disconnecting both sensors and the buzzer and light still came on,oil level all ok,looked at all the wiring I can get to and it all seems ok,took off dash cover and cleaned up white multiplug contacts,ive driven a fair bit since this started with frequent checks in the engine bay and don't see anything amiss,need some clear heads to read this and give me your thoughts please,thanks Laurence.

The "buzzer of doom" switch is a different kind to the standard oil pressure switch. It is held closed by the oil pressure, and is open when there is no pressure, so disconnecting it will definitely set off the BoD above 2000RPM.

My guess is that the switch has packed up [E D I T]or is the wrong one[/E D I T]. You can test the switch with a multimeter set on Ohms range. Should be Zero ohms across the switch with engine running at more than 2000RPM , and infinite when not running. New ones are readily available, but you'll need one specific to the engine, not the vehicle, because they operate at different pressure settings.

If you connect the wire to a good ground, it should stop the buzzer if the electronics is working OK.

Switch on the ignition and disconnect each oil pressure sensor in turn. Disconnecting one of them will put the oil pressure warning light out. The other one is the 2000rpm "buzzer of doom" switch. Reconnect the one that put the light out and connect the wire from the 2000rpm switch to ground. You should then find that the oil pressure light goes out on starting and stays out. If it comes on and the buzzer sounds, then there is a bad connection in the wiring to the 2000rpm switch. If the light stays out but the fault comes back when the switch is reconnected, check that you have the correct switch. If switch is OK then oil pressure needs checking.

hi guys,thanks for your replies,this is weird as this afternoon I drove the van for about ten miles and no warning light or buzzer came on,i will try your recommendations and let you know how I get on,cheers Laurence.

My recommendation would be to check the oil pressure with a mechanical gauge at the filter housing when it is acting up. Your warning system could be trying to warn you. Once you have verified the pressure, you can then work out the electrical glitch. It is possible in rare cases for the pressure relief valve to stick open and much of the oil bypasses when this happens.

hi,ive been driving around for quite a few miles since last post no problems,then yesterday the buzzer and light came back on,keep checking engine and all seems ok,1.9td aaz,ive searched/looked for oil pressure relief valve,does my engine have one and if so where is it ?,thanks Laurence.

The relief valve is in the oil pump pickup cover. You really should verify your oil pressure with an actual gauge when it is acting up. If the oil pressure is below spec at the threshold rpm, the buzzer will sound. You've already been advised how to disable the warning, but I would only do that once you verify the oil pressure is in spec. There are switches that require less oil pressure to stay closed.

hi rsxsr,driving today and all ok,i wont be disabling any alarms till ive sorted this out,you say switches have different pressure ratings,would you or anyone reading this know the ratings for the white and blue switches on my 1.9td engine,ive looked in manuals etc but cant find this to verify my switches are the right ones,thanks for your replies Laurence.

I'm no expert but i was told that the pcb for the oil buzzer is behind the speedo (its L shaped). I would lighty spray some wd40 over the board and disconnect and clean the terminals and refit. Condensation can cause this type of issue. Ps don't spray the speedo directly!

Let me know if you'd like a photo i have one available to photograph

Ps mind the screws in the binical it's fragile

Hello, I don't know that you can just go by the color of the switch. The underside of the switches should have a part number and a working pressure stamped into them. I am looking at my World Pac Catalog.

1 pin Brown .3 Bar or Blue .25 Bar 028 919 081 H
1 pin White 1.8 Bar, this one controls the buzzer circuit 056 919 081
1 pin Black 1.4 Bar, this one would require less pressure to keep the buzzer off. 068 919 081 D
1 pin Grey .75 - 1.05 Bar this one was fitted to the 2.1 WBX and worked at even lower pressure. 068 919 081 A

Seems like the WBX sensor would give you the least sensitivity.

hi rsxsr,i got two new switches from brikies,white and blue for my aaz,been ok for last few days but still gonna do a pressure test,starter motor went yesterday so had to get that refurbed,dont you just luv these vans, .

hi all, so I did an oil pressure test today, from cold start the gauge showed 6 bar/85 psi,got it up to running temp/idling it showed a fraction under 1 bar/12 psi, then at 2000 rpm it was 2 bar, your thoughts/comments on these figures please,thanks Laurence.

Ok, general rule of thumb in psi. You'd like to see 10 psi for every 1000 rpm on any engine. Now, the dynamic pressure switch needs 1.8 bar to remain closed. There is also around a 2200 rpm requirement. So, based on your testing you are within the safe range of the engine and keeping the buzzer off. If your pressure drops below 1.8 bar at 2200 rpm, you will find that the buzzer probably will go off again. In a case like this, I'd lean towards maybe the 1.4 switch I posted or even the original WBX sensor. These bottom ends are pretty stout and should live for many miles. mark

hi mark, on the road last night and the buzzer went off again, I will try the 1.4 switch and see how that goes, also I asked in a garage and they asked what oil i was using, told them 15w40 mineral, they looked on there computer for my engine, 1.9td aaz, he said I had the wrong oil, should be 10w40 semi synthetic for diesel turbo, could this make a difference?, anyone have any views/thoughts on this,thanks Laurence.

I use Shell Rotella Synthetic in my TDI. I believe it is 5w-40. There are a few things going on with oil temp and viscosity that affect pressure. First of all, all oils have about the same pouring viscosity at operating temperature. Choosing the proper viscosity oil is based on ambient temperature. If your oil is too thick, that causes friction and friction puts heat into the oil thinning it out and the pressure drops. So thick oil is not always ideal. Too thin and the oil can't protect the loads on the bearings. I would recommend following the manufacturer's oil spec what ever it is.

Before you replace the dynamic oil pressure switch, since you have verified you have reasonable oil pressure already, you can now ground the wire that connects to this switch and drive it for a week or so. If the buzzer stays off, you have tested the circuit as good. Then swap in the 1.4 bar switch or leave it permanently grounded.

I say this because unless you are running a cheap oil filter or have an external oil cooler, and keep your eye on the oil level, it is unlikely you need the dynamic circuit. VW added this circuit because owners were running the engines out of oil. Mostly because in the US market, gas stations were going to self serve at the time, and you did not have the attendant checking the oil during a fill up. A qt in 1000 miles is acceptable. 5000 miles and the engine is toast if you don't keep the level up.

I have my dynamic system disabled on my vanagon, not because it has a problem, but because I stay on top of the oil level. Again, these bottom ends last forever. I hope I have been of some help. mark