1915 Dg 5 Speed 1990 Oil Warning Light Buzzer Of Doom

Post by **Dave Mason** » 22 Dec 2020, 20:40

Hi there
Does anyone have any ideas why the warning light & buzzer comes on ?
It comes on after about 4-5 Miles,
The oil is at the Maximum Mark.
The light & buzzer goes off when the clutch is dipped & the engine is revved. ??

I've read on the Wiki Boards that it could be a printed Circuit board Issue....
Does this sound about right ?

After watching some videos, I came across a Cluster Repair Kit. VW T25, T3, Vanagon Dash Clock Hard Wire Upgrade *CMBA*Do you guys recommend this product ?

Any input would be greatly appreciated ....
Thanks
Dave

Post by **DoubleOSeven** » 22 Dec 2020, 20:56

Might be the blue oil pressure sensor under the push rod tubes. I’d take it out and test that you haven’t actually got low oil pressure with a wet gauge first though before buying a replacement.

Post by **Mocki** » 22 Dec 2020, 22:04

Get the actual oil pressure checked ......

Then, if the oil pressure is good enough, star a visual inspection of the wiring in the engine bay , replace the switches and clean the connections , but it sounds like pump issues from your description

Post by **Dave Mason** » 22 Dec 2020, 22:38

Thanks 007....
Good advice .....
Do you know how to determine the revs?
Thanks
Dave

Post by **Dave Mason** » 22 Dec 2020, 22:39

Thanks Mocki....
Again... Good advice ....
Thanks

Post by **ajsimmo** » 23 Dec 2020, 01:25

It won't be the blue switch. The buzzer doesn't come on with that one, but only comes on if the DOPS board in the dash doesn't detect 0V (earth) at the front switch (beneath water pump pulley) at over around 2000rpm.
Your switch may be one of three switching pressures;
~0.9, 1.4 or 1.8 bar. There's a good explanation of all this on Brickwerks site, btw.
It sounds like it's working correctly, and behaving as if your hot oil pressure is just below borderline with a 1.8 switch. VWs workaround when this was a current model was to fit a lower pressure switch - If you already have a lower pressure switch you've got problems! I note that the buzzer goes off when revved higher. This is correct and shows it's almost certainly not a wiring or dash fault, but that the engine is making enough pressure to close the switch at higher revs.
So, as said, wet test first to get a useful picture of what's actually going on. Also check which switch. Then come back and I'll gladly advise further, as will others, I'm sure.

PS in case you don't have the spec, should be min 2bar oil pressure @ 2k rpm @ 80°C. That's why a borderline worn engine with a 1.8bar switch gets occasional BOD at 2k rpm on a hot day.

Sent from my ONEPLUS A3003 using Tapatalk

Post by **Dave Mason** » 24 Dec 2020, 00:15

Thanks Guys...... & ajsimmo
Ok..... I picked the van up yesterday..... Drove it 3-4 miles & the gears stuck in 3rd....
Called the RAC .... guy was really helpful & greased the linkage.... Said it was lack of maintenance.... It's only done 120 miles in the past 3 years....
I asked him about the buzzer, & the dip stick was showing just over the high mark, He suggested it could be a faulty pressure switch....
So i went on my way.... 3-4 miles later the buzzer comes on.... I stopped for about 10 minutes, then off i went.... You can see a repeat pattern here....
I stopped again, waited 10 minutes etc.....
Didn't go over 40mph.... found out that when the buzzer came on & I revered it , it'd go off for a few minutes.... So kinda limped home...

Ok.... This morning the really nice RAC man gave me a call !!!.... Asking did I make it home ok....
He suggested it could be really thin oil....
So... this afternoon I was emptying the back out & found a near full 5 litre oil container.... 5w-30 Premium semi synthetic Triple QX
After checking on here , there's no mention of 5w-30.... more like 10-40 or 15-40....

I've ordered a pressure tester.... Arrives Saturday....
The RAC guy suggested to flush out the old oil & replace with new oil...
( He didn't know that it could be running on 5-30 , nor do I....It might of just been bought to top it up with.....as it's nearly full)....

So..... Could you advise what oil should I buy to do a flush & what oil should I buy to do a repeat pressure test ?
He also said it could be the oil pump ?
Hoping & crossing my fingers, it's not goosed the engine.....

Post by **DoubleOSeven** » 24 Dec 2020, 05:22

https://www.brickwerks.co.uk/t3-parts/e ... la-5l.html

Just change the oil to Mineral 15W-40 only and I’m confident you’ll get oil pressure back. Don’t max it., 4L to start with, then small top ups, Ideally you want it half way between top & bottom line on dipstick. Change the oil filter to W719/12 too. Oh and take it easy with that sump plug when you tighten it up, 25Nm from memory, the case is only aluminium and you don’t want to ruin the M14 thread. Sump plug needs a new copper washer too.

https://www.brickwerks.co.uk/oil-filter ... etrol.html
https://www.brickwerks.co.uk/sealing-wa ... opper.html

Brickwerks do a nice service kit, which captures all this plus more.

Post by **DoubleOSeven** » 24 Dec 2020, 08:24

Oil flushing is something garages put on your bill for extra revenue. Car manufacturers don’t mention oil flushing in their workshop manuals or instruction manuals...but that’s another thread for discussion maybe.

Post by **davidoft1** » 24 Dec 2020, 10:46

DoubleOSeven wrote: ↑24 Dec 2020, 08:24 Oil flushing is something garages put on your bill for extra revenue. Car manufacturers don’t mention oil flushing in their workshop manuals or instruction manuals...but that’s another thread for discussion maybe.

Flushing is necessary on some occasions, like if you don’t know what oils in it and you want to be sure to get it all out.

Post by **davidoft1** » 24 Dec 2020, 11:06

You don’t necessarily need to do a flush but it may help, I’ve used oil treatments in the past and they’ve worked as claimed , 5-30 semi is modern engine oil, not really want you want and may well be the reason for the oil pressure light , or it may have been put in in attempt to stop flattery cam followers, change to the recommended 15-40 or 20-40, new oil filter too, cheap pressure gauges are ok but I don’t find them accurate enough and the margin between allowed minimum oil pressure and the switch isn’t big so look for a more accurate gauge

Post by **davidoft1** » 24 Dec 2020, 11:07

davidoft1 wrote: ↑24 Dec 2020, 10:46
DoubleOSeven wrote: ↑24 Dec 2020, 08:24 Oil flushing is something garages put on your bill for extra revenue. Car manufacturers don’t mention oil flushing in their workshop manuals or instruction manuals...but that’s another thread for discussion maybe.

Flushing is necessary on some occasions, like if you don’t know what oils in it and you want to be sure to get it all out. It’s not purely a way to charge for unnecessary work

Post by **Dave Mason** » 24 Dec 2020, 14:33

Hi....
Thanks very much for the links.... I've ordered....

I'll just spoken with the mechanic who services my vans....

He's suggesting going back to mineral it'll need a flush....
His suggestion is to drain some oil....
Add flushing & run till warm...
Drop it all out....

Without the drain plug pour 10 litres of diesel through....

Don't run it just let it run straight through ...

Remove old filter & leave for a few days to completely drain...
Replace with Mineral...
How does that sound ?

Post by **ajsimmo** » 24 Dec 2020, 15:01

15w40 mineral is good, cheap and readily available, but 15w50 is a better option to maintain a bit more hot oil pressure.
https://www.brickwerks.co.uk/engine-oil ... ma-5l.html

And no to all that flushing malarky. Completely unnecessary, and a waste of time/money imho. I'd rather have traces of residual semi-synthetic engine oil mixed in, than have diesel in my oil! Just change the oil and filter.

Sent from my ONEPLUS A3003 using Tapatalk

Post by **davidoft1** » 24 Dec 2020, 15:08

ajsimmo wrote: ↑24 Dec 2020, 15:01 15w40 mineral is good, cheap and readily available, but 15w50 is a better option to maintain a bit more hot oil pressure.

And no to all that flushing malarky. Completely unnecessary, and a waste of time/money imho. I'd rather have traces of residual semi-synthetic engine oil mixed in, than have diesel in my oil! Just change the oil and filter.

Sent from my ONEPLUS A3003 using Tapatalk

Diesel hey, maybe 50 years ago, techs moved on, in my opinion it’s perfectly good for it’s purpose

Club 80-90 Forums