Sudden buzzer of doom
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Sudden buzzer of doom
Had the van for five years, never a problem. Regularly serviced, etc. 2.1 petrol.
Haven't driven it for a week or so, so went to take it for some petrol, prior to the MOT. Drove about 200 yards and the Buzzer comes on, with the flashing oil light. Never seen or heard this before. Went home, checked and topped up the oil (it was a bit low), then tried again. Got a bit further this time - maybe 400 yards - and it starts again. Buzzer and flashing light. What's this all about then?
I know that light flashing with buzzer means low oil pressure, but why would it go off all of a sudden, when the engine is cold?
Seems unlikely to be a wiring fault either, as it doesn't come on straight away.
Any help gratefully received.
Haven't driven it for a week or so, so went to take it for some petrol, prior to the MOT. Drove about 200 yards and the Buzzer comes on, with the flashing oil light. Never seen or heard this before. Went home, checked and topped up the oil (it was a bit low), then tried again. Got a bit further this time - maybe 400 yards - and it starts again. Buzzer and flashing light. What's this all about then?
I know that light flashing with buzzer means low oil pressure, but why would it go off all of a sudden, when the engine is cold?
Seems unlikely to be a wiring fault either, as it doesn't come on straight away.
Any help gratefully received.
1990 2.1 DJ Syncro Caravelle/Westfalia conversion RHD
- mrhutch
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Re: Sudden buzzer of doom
wire to the sensor between the pushrod tubes come adrift?
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- Ian Hulley
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Re: Sudden buzzer of doom
mrhutch wrote:wire to the sensor between the pushrod tubes come adrift?
Nope, the wire across the top to the sensor near the oil pump either become brittle and broken or the terminal come off. Possibly the twin connection near the black box become gnarly and horrible.
Ian
The Hulley's Bus
1989 2.1DJ Trampspotter
LPG courtesy of Steve @ Gasure
1989 2.1DJ Trampspotter
LPG courtesy of Steve @ Gasure
Re: Sudden buzzer of doom
Well there will be many forum members who will know more about this than me. But having recently discovered that the Buzzer of Doom oil pressure switch lead has been deliberately grounded since I have had the my 2.1 DJ WBX - some ten years , I am starting to take an interest in the dark art of WBX electricks.
I did read in my Bentley's manual that the Buzzer of Doom box of tricks - not sure where it resides - takes it's input from more than one source - one being a registering of over 2,000 RPM from the ECU and another being the pressure switch (closes at 0.9 bar) low on the front (back of the van) of the engine.
The reason for the the delay might therefore be that the engine hasn't reached 2,000 RPM yet or that there is a deliberate delay in the circuit to reduce spurious activation.
I would be interested to know if the normal red oil warning light (opens at something like 0.3 bar) - which I believe takes it's input from the pressure switch under the left pair of cylinders - goes out immediately on starting the engine. I would be reluctant to drive the van should this light fail to extinguish as soon as the engine kicks in.
Let's see what the forum experts have to say though:
I did read in my Bentley's manual that the Buzzer of Doom box of tricks - not sure where it resides - takes it's input from more than one source - one being a registering of over 2,000 RPM from the ECU and another being the pressure switch (closes at 0.9 bar) low on the front (back of the van) of the engine.
The reason for the the delay might therefore be that the engine hasn't reached 2,000 RPM yet or that there is a deliberate delay in the circuit to reduce spurious activation.
I would be interested to know if the normal red oil warning light (opens at something like 0.3 bar) - which I believe takes it's input from the pressure switch under the left pair of cylinders - goes out immediately on starting the engine. I would be reluctant to drive the van should this light fail to extinguish as soon as the engine kicks in.
Let's see what the forum experts have to say though:
Well-timed silence hath more eloquence than speech.
"A quiet shy boy who took little part in games or sport"
88 High top 2.1 WBX
"A quiet shy boy who took little part in games or sport"
88 High top 2.1 WBX
- Ian Hulley
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Re: Sudden buzzer of doom
Mr Bean wrote: The reason for the the delay might therefore be that the engine hasn't reached 2,000 RPM yet or that there is a deliberate delay in the circuit to reduce spurious activation.
It has to reach a certain RPM before it's triggered.
Ian
The Hulley's Bus
1989 2.1DJ Trampspotter
LPG courtesy of Steve @ Gasure
1989 2.1DJ Trampspotter
LPG courtesy of Steve @ Gasure
- 937carrera
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Re: Sudden buzzer of doom
It's pretty unlikely that the oil pressure is low on a cold engine, so more likely wiring.
There's a wire (should be yellow) that goes to the oil pressure switch near the fan pulley.
The buzzer only operates when the engine is doing over 2000 rpm, if you earth the lead to the engine (dizzy probably has a spade on it) this should defeat the buzzer, so it doesn't sound at all.
If that's what happens, then you have narrowed down the problem to either wiring or the oil pressure switch itself
Have a read here - http://forum.club8090.co.uk/viewtopic.php?f=39&t=163521 not from the beginning, but from the point where I recommissioned my DOPS system.
Can you confirm that on idle the oil pressure light is not illuminated (if it is on a cold engine switch the engine off) - this works on a different pressure switch
There's a wire (should be yellow) that goes to the oil pressure switch near the fan pulley.
The buzzer only operates when the engine is doing over 2000 rpm, if you earth the lead to the engine (dizzy probably has a spade on it) this should defeat the buzzer, so it doesn't sound at all.
If that's what happens, then you have narrowed down the problem to either wiring or the oil pressure switch itself
Have a read here - http://forum.club8090.co.uk/viewtopic.php?f=39&t=163521 not from the beginning, but from the point where I recommissioned my DOPS system.
Can you confirm that on idle the oil pressure light is not illuminated (if it is on a cold engine switch the engine off) - this works on a different pressure switch
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
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Re: Sudden buzzer of doom
I can see the wire, but the sensor has so far eluded me. Are they particularly well hidden on a Syncro?
1990 2.1 DJ Syncro Caravelle/Westfalia conversion RHD
- 937carrera
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Re: Sudden buzzer of doom
From bigbadbob76's post in the thread above
You can see the fan pulley in the Samba post, top right, I don't think they are different on a syncro
You can see the fan pulley in the Samba post, top right, I don't think they are different on a syncro
bigbadbob76 wrote:Hmmm......
Comparing the one on "the samba"
With mine...
It dosn't look like mine ever had a sender there, but it's a b suffix engine in a 1986 van, and has the yellow wire that someone has earthed.
I'm confussed dot com.
Unless someone stripped the thread and welded up the hole.
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
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Re: Sudden buzzer of doom
I would clean off the grot and see whats under there.
FYI, there are no "sensors" on a wbx, just a few passive senders (variable resistance for temperature) and some switches (such as those for oil pressure)
Both need a good earth return at the engine (earth strap to chassis) and the instrument pack (earth crowns) to function correctly.
The oil pressure lead on the switches (brown) is prone to the crimped terminals in the white plug going green with corrosion, causing the buzzer to sound in error due to poor continuity.
Sent from my S60 using Tapatalk
FYI, there are no "sensors" on a wbx, just a few passive senders (variable resistance for temperature) and some switches (such as those for oil pressure)
Both need a good earth return at the engine (earth strap to chassis) and the instrument pack (earth crowns) to function correctly.
The oil pressure lead on the switches (brown) is prone to the crimped terminals in the white plug going green with corrosion, causing the buzzer to sound in error due to poor continuity.
Sent from my S60 using Tapatalk
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Re: Sudden buzzer of doom
Sounds like a job for the weekend. I'll dig out my little wire brush.
Am I right in thinking that if I earth the sender wire to the spade on the distributor, and the buzzer stops, then the fault is in the sender?
But doesn't that also mean that if the fault is in the wire, then the buzzer will still sound?
And if the poor connection is somewhere else, it will still sound?
Just trying to work out the variables...
Am I right in thinking that if I earth the sender wire to the spade on the distributor, and the buzzer stops, then the fault is in the sender?
But doesn't that also mean that if the fault is in the wire, then the buzzer will still sound?
And if the poor connection is somewhere else, it will still sound?
Just trying to work out the variables...
1990 2.1 DJ Syncro Caravelle/Westfalia conversion RHD
- 937carrera
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Re: Sudden buzzer of doom
Yep, earth the sender wire on the dizzy and the DOPS/ buzzer function is defeated. It thinks oil pressure is good.
Yep, If there's a fault in the wire meaning that placing the wire on the dizzy isn't actually creating a circuit to earth, then DOPS buzzer will operate (above 2000 rpm), and you will know that it's a false warning.
You test the wiring by earthing / not earthing the wire and revving above 2000 rpm
Easy things first though - find the pressure switch and make sure the connection is good, as Silverbullet said above
It'll probably take longer to find the oil pressure switch than test out the wiring
Yep, If there's a fault in the wire meaning that placing the wire on the dizzy isn't actually creating a circuit to earth, then DOPS buzzer will operate (above 2000 rpm), and you will know that it's a false warning.
You test the wiring by earthing / not earthing the wire and revving above 2000 rpm
Easy things first though - find the pressure switch and make sure the connection is good, as Silverbullet said above
It'll probably take longer to find the oil pressure switch than test out the wiring
Last edited by 937carrera on 11 May 2018, 15:56, edited 1 time in total.
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
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Re: Sudden buzzer of doom
I have all of this do to restore the wiring on our Doka WBX after some clown earthed it out...
http://www.thelittleredbus.com" onclick="window.open(this.href);return false;
VW 2.1 WBX DJ Syncro Doka - SOLD
VW 1.9 TDi AHU Syncro Camper
VW 2.1 WBX DJ Syncro Doka - SOLD
VW 1.9 TDi AHU Syncro Camper
- 937carrera
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Re: Sudden buzzer of doom
Same clown earthed mine out and cut the tacho feed signal too
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
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Re: Sudden buzzer of doom
Found the sender, but had to undo the alternator belt to get at it. The connection seems good (and it had a cover on it), now I’m trying to earth it. No spade on the distributor, so trying to find somewhere else. Cable looks a little worn in places, and the casing seems to have melted at one point, but appears to be sound.
1990 2.1 DJ Syncro Caravelle/Westfalia conversion RHD
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Re: Sudden buzzer of doom
Does it have to be a fixed connection to earth? Could I hold it to ground, then move it away, then put it back, etc?
Sort of switch it on and off?
Sort of switch it on and off?
1990 2.1 DJ Syncro Caravelle/Westfalia conversion RHD