oil pressure switch ?

[tinman]

OK guys need some help please.
Just changed my engine 1.9 dg
the engine I took out had 2 oil pressure switches 1 by the filter and 1 by the pushrods
The replacement engine has only 1 switch the 1 by the push rods
When the engine was started every thing seemed ok but when I reved it up the oil light and buzzer started.
so I checked the pressure relief valve - all Ok.
then removed pressure switch fitted pressure gauge oil pressure fine BUT rev up engine oil light and buzzer start again ( not even connected)
So I now know its wired wrong
How should I wire it up??
Thanks..

[peteabbott]

I had the same problem, very annoying as I too checked the oil pressure with a guage and all was fine, thought OK then I have warning lights on the dash for oil and water problems so I errrrr diconected the buzzer of doom, seemples ! Tut Tut I hear you say but by disconnecting the buz of doom will it affect anything else, I think and hope not but I have done lots of buzzer free miles since. Think I will just fit a permanent pressure guage.

[AngeloEvs]

You need to have both oil pressure switches if your van has the later DOPS (Dynamic Oil Pressure System) PCB in the speedo housing. At the moment, your buzzer is sounding because the second oil pressure switch is missing. You will either have to modify the engine as necessary to include the second switch or modify the oil pressure warning circuit for a single LED as was fitted until 1986. Alternatively, fit an oil pressure gauge and remove the pcb in the speedo housing.

[toomanytoys]

2 ways to "cure" this... fit the second pressure switch and connec the wire to it... (better IMHO)
Or... just earth the wire.. this will prevent the buzzer from sounding above 2000 rpm... no need to change the dash buzzer pcb etc..


Oh the oil light works off the pressure switch under the pushrod tubes, good idea to fit a new one here...

BUT.. You really should do a hot oil pressure check on the engine to be sure its ok (if second hand) as basically thats what the second pressure switch does... (but when that comes on its often a bit too late too)

[tinman]

OK Thanks
I've already run the engine up to temperature with the pressure gauge connected it was between 20 - 30 psi
when hot depending on revs and about 55 psi cold !!

[VWCamperfan]

Not the same engine but I have recently changed my dashboard to a digital one and had to find a way round this problem as I now have a buzzer of doom and only one pressure switch.
How I got round this was to buy a dual low and high pressure switch in one. When the engine revs reach about 2000 rpm, give or take a bit, the dash will read the pressure of the second switch and if you havn't got one, the buzzer will sound.
VDO do a dual pressure switch, may be worth a look but make sure there is enough room for the new switch and that it operates at the required pressure as there are a few different pressure settings for them.

[toomanytoys]

But earthing the second pressure switch wire/feed is the easiest... most vehicles live with only 1 pressure switch... my early caravelle has only 1...... my late Syncro doka has a faulty second switch and the wire has been earthed for.... ooh... 3 years... (several reasons why it hasnt been changed... not just because I cant be arsed... ) and that has done 45k km like that... a lot of them at 4000 rpm on the autoroutes...

[tinman]

Cheers Mate , Thats what I'll be doing

[4gearwonder]

Hiya,

Had same problems T as yourself and went through all the senarios of checking/replacing pcb circuit, checking all earths, replacing both oil sensors, changing to new oil/filters etc..., but light still came on in certain conditions

Bottom line though. Got a second hand oil pressure switch from a vw coupe (believe it was a 96?) and second hand vdo oil gauge, both from ebay and fitted. Now know exactly what oil pressure is going on in engine and not bothered by intermittent lights scaring you as you go along on holiday!

PS. our engine is a 1y 1.9 diesel, just for the record.

Another option maybe if you're still having problems trying to resolve? All the best with things though

Cheers.