Oil pressure

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Chomley
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Oil pressure

Post by Chomley »

Hi all new member here, and boy I need help!

I have an issue with a newly purchased t25. The problem is that the oil pressure warning light flashes when reved ,

And before you scream not again, I’ve read with great interest the posts regarding this issue but after lots of looking testing prodding cleaning the dam things still doing it, I’ve purchased an oil pressure gauge and tested the lower oil pressure switch position which gave a low reading of just below 5bar at idle and and just above 5 when reved to around 2000 rpm. I’ve cleaned all terminal on rear of dash board and cleaned the crown earth thingys which resulted in my temp gauge working and my fuel gauge reading much higher than before. I’ve tested switch wiring from front to rear which was all good, I’ve removed the rear sensor ,put meter across the sensor expecting it to make a earth but it didn’t not does this sensor operate differently to the lower sensor as when that one was tested it made circuit, had continuity however you want to put it,

Any help regarding the rear sensor operation or anything else I can check please reply ..

Thanks all
Van reg D752yph chassis wv2zzz25zhh041217. Engine dg124439 ,recorded miles 202000.

Purple

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itchyfeet
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Re: Oil pressure

Post by itchyfeet »

Chomley wrote: I’ve tested switch wiring from front to rear which was all good,


How did you test it ? multimeters lie to you you must test it with a lamp that draws some current

Chomley wrote: I’ve removed the rear sensor ,put meter across the sensor expecting it to make a earth but it didn’t not does this sensor operate differently to the lower sensor as when that one was tested it made circuit, had continuity however you want to put it,

it is normally open with no oil pressure the low switch is normally closed with no pressure.

ground the high pressure switch wire at the dash if the buzzer is quiet then work back along the wiring until you find the break in the wire.

If the buzzer sounds with the high pressure switch wire grounded at the dash then the dash is probably at fault.
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
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Chomley
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Re: Oil pressure

Post by Chomley »

Firstly thanks for replying, I tested switch with multi meter from spade connector to switch body lower one ade circuit upper didn’t so I assumed it was naf as lower was opposite . But you’ve just let me know that it should open so it’s good possibly I haven’t tested for change of state if you know what I mean so could be a naf sensor ,do you know what the sensor should be as the one fitted was black caked in crap and I couldn’t make out the markings,

Hope that makes sense .

The other thing is you mention a buzzer mine hasn’t got one just a flashing oil light it flashes ignition on goes out when running but if your hold the revs at around midway not thrashing, the oil light begins to blink, as said oil pressure at lower point is 5bar ish hot,cold reved idled. The engine runs great quiet,pullls well, no smoke I. Confused

Chomley
Van reg D752yph chassis wv2zzz25zhh041217. Engine dg124439 ,recorded miles 202000.

Purple

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itchyfeet
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Re: Oil pressure

Post by itchyfeet »

put your van details and age in your signature

is it a wbx.?

if you have two switches and an early van with no buzzer then the rear switch isn't used

low pressure switch...

https://www.brickwerks.co.uk/oil-pressu ... -blue.html" onclick="window.open(this.href);return false;

reads like a duf switch as it has to go.closed to bring light on.and it should not do that running.
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
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itchyfeet
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Re: Oil pressure

Post by itchyfeet »

Have you come over here from the yard?
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
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Chomley
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Re: Oil pressure

Post by Chomley »

I’m getting the feeling I might have some of Frankenstein’s motor .. added details to signature, I’m happy motor has oil pressure and is sound but I really want the bloody lamp to stop flashing , last resort will be dash mounted gauge an disconnect the dam light..

Cheers chomley
Van reg D752yph chassis wv2zzz25zhh041217. Engine dg124439 ,recorded miles 202000.

Purple

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937carrera
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Re: Oil pressure

Post by 937carrera »

Earth the wire to the high pressure sender - that will defeat the DOPS system, so no flashing light there's a handy earth on the distributor on mine. :wink:

The have a read of this https://www.brickwerks.co.uk/brickwerks ... -switches/ and have a think. You won't have 5 bar ish oil pressure with a hot engine, which is what I think you said above.

Let us know what colour oil pressure switch you have fitted - that should tell us what version and rating it is. When updating the engine details, please also say what oil you are using.

update: just seen the note about the black oil sender - if it is black it's a 1.4 bar version normally used on diesels, but nothing wrong with fitting it on a DG
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

Chomley
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Re: Oil pressure

Post by Chomley »

Yep 5 bar ,, but the gauge was £14 on eBay I think I might test that out tomorrow with my compressor .

Oil and filter changed last week prior to mot which it passed, oil 15/40 shell helix flushed first, oil filter from euros.

W
L check gauge first thing recheck everything and run the extra earth if all fails.

Will post result

Thanks you lot.
Van reg D752yph chassis wv2zzz25zhh041217. Engine dg124439 ,recorded miles 202000.

Purple

Chomley
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Re: Oil pressure

Post by Chomley »

Morning people me again I can almost hear the groans from here.

Right borrowed another gauge results as follows

Cold tick over 5 bar or maybe just a traction under. No oil light!
Cold reved to around 2000 rpm 5.1 bar ( oil light triggered and flashes even when revs return to idle)

Hot engine left to warm to mid point on dash

Hot at idle 2.5 bar ( oil light off as stopped and restarted)
Hot reved to approx 2000 rpm instantly raised to approx 4.8 bar ( oil light flashing again)

No nasty knocking just the to old ladies knitting clatter from tappers,( hardly audible)

No smoke when reved hard or knocking..

That’s it lost about half a cup of oil where gauge was fitted but I was gentle with tester when winding into cylinder so I guess it may have been a little down due to leek.

What do you reckon chaps can I set off down the coast for a couple of days ( the wife really wants to) or should I continue to search for this fault. Earlier the suggestion was to run an earth from upper switch wire to ground out and full the system ..

Look forward to replies but at least I know I’ve got what appears to be healthy pressures.. if anybody wants to here engine I did video it running but I would have to send it via email ..I. Guessing you’ve all got better things to do though, as owning one of these things appears to be a full time job.

Van mileage is 202000 ,it’s purple( I know but the wife loves it)

Cheers all chomley
Van reg D752yph chassis wv2zzz25zhh041217. Engine dg124439 ,recorded miles 202000.

Purple

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937carrera
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Re: Oil pressure

Post by 937carrera »

Those oil pressures do look exceedingly good, here's mine for comparison http://forum.club8090.co.uk/viewtopic.p ... 6&start=60 using thicker 20W50 oil

Cold tickover - 5 bar vs 4.2
Cold 2000 - 4.5 bar vs 5.1

Cold pressures are less important, lets have a look at hot / 80 C

Idle 2.5 bar vs 1.2 bar
2000 - 4.8 bar vs 2.2 bar

Now my engine has done 43,000 miles and at 2.2 bar just meets the VW min spec of 2 bar at 2000rpm @ 80 deg C, itchyfeet has a fresh engine and that's showing about 3.5 bar on 15W50

If you are happy the measurements are correct then I suppose you simply want to defeat the warning system (can you confirm the flashing light only comes on above 2000 rpm)

From what you have said it sounds as though the high pressure switch is broken, the wire is not connected or there is a break in the wire from the dash to the engine compartment. If you earth the wire and the buzzer still sounds then it's going to be a break in the wire or some other fault with the DOPS system.

Earth the wire that connects to the high pressure switch side and report back
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

Chomley
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Re: Oil pressure

Post by Chomley »

Ok dokey thanks for the comparison readings, mine have been checked with two gauges now which have given very similar results( happy days)

Now I’ve just been out to her again replaced btm sensor .15 to .35 which was bought from local dealer saying that’s the one listed. It’s black in colour so non original

The other higher switch wa been removed yesterday and after cleaning it up , 50950 and 16/10 stamped into it ! This Has been replaced with the lower level sensor so at present I’m guessing that this switch which is normally showing a circuit until pressure is achieved, is now breaking circuit when up to pressure and giving no earth hence the flashing light ( by the way I haven’t got a buzzer but judging my the mess that is the back of the dash held together with tape my suspicion is that there may well of been a buzzer at some point but has been butchered out and all that remain is flashing light.

Anyhow I have now supplied that wire from high pressure ( upper. Sensor)/ with a earth to engine block and hay presto no blinking oil light (hurrah) Now I know this is a bodge and it’s not something I condone but the bloody light was making me pull my hair out and I need all I’ve got.

Is there in your opinion any point in testing the pressure at upper switch point which I’m sure you know is a little tricky to access or do I get you guys to give me the right sensor type and fit that and remove bodge earth and test again ,,, please say no !! !

Thanks again you guys your help has kept me sane..

Chomley
Van reg D752yph chassis wv2zzz25zhh041217. Engine dg124439 ,recorded miles 202000.

Purple

Chomley
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Re: Oil pressure

Post by Chomley »

By the way do you lot ever meet up at events as I feel I owe a beer or two!
Van reg D752yph chassis wv2zzz25zhh041217. Engine dg124439 ,recorded miles 202000.

Purple

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937carrera
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Re: Oil pressure

Post by 937carrera »

let's make sure we're talking the same things - pictures would be good.

Low pressure switch, bottom left of the crankcase, between pushrod tubes. Should be blue, operates when pressure is below 0.25 bar

High pressure switch, rear of the crankcase near pulley, Depending on year should be grey or white. Was the one you removed white, should have said 1.6-2.0 bar, not 1.0

Image

You can't swap between low / high switches. One of them (low) is normally closed, the others normally open.

Follow the Brickwerks link I posted and choose one of the high pressure switches. They all fit / work, varied according to model / year. Fit it and reconnect the wire and silence should continue :)
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

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937carrera
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Re: Oil pressure

Post by 937carrera »

There are some meet up events / shows, but no club type meetings that I'm aware of. Joining the forum isn't the same as joining the club though, members have their name in blue or green
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

Chomley
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Re: Oil pressure

Post by Chomley »

Hi all

Tried posting a picture but file to big ?!

The one near water pump is the issue ( high pressure)

The switch I remove was black in colour with markings stamped into nut edge of 16/10 and 50950 that’s it nothing else..

So I need the 1.6/ 2 bar to replace which I will order now suggested suppliers you trust please.!

A little history i your ineterested bought van 2 weeks ago eBay for £2050 did notice the oil light on purchase but was assured by owner that it was probably wiring related and as engine sounded good was willing to take a chance!

Mot last week which it passed with a couple of advisory’s which are now sorted ,mentioned to mot guy that the oil light was worrying but he said the engine sounds fine and that for the type of van he had seen a lot worse,

Reassured I set about trying to sort by replacing sensor lower as just about everything I had read was related to this or wiring issues with dash or earthing crown which have all been cleaned only to increase brightness of dash lights and fuel gauge reading higher tnan it was before ( on pick up we refuelled as showing low fuel and only manage to squeeze £25 in before it started overfilling) temp gauge is also now consistent as was all over the place on pickup)

That’s it really until you all came about and sorted it for me.. bearing in mind the high mileage I’m amazed but was given folders with van one of which must obtain 70/80 invoices for service repair and pictures of when it was white ( which I prefer) and a bill of £2600 for panel repair and painting. ( in The now god awful purple) the wife likes it..

Might try and address that to a white over blue as and when I address the little bits of rust coming through.not bad though for. 10 year old respiratory.

Chomley
Van reg D752yph chassis wv2zzz25zhh041217. Engine dg124439 ,recorded miles 202000.

Purple

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