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Oil pressure switches

Posted: 27 Mar 2017, 18:58
by IAN-H
I gather there are are two oil pressure switches on a VW diesel engine. (mine's a 1.9 TD.) switching at different pressures. Would someone tell me where both of these switches are located and which is which? Thanks Ianh

Re: Oil pressure switches

Posted: 27 Mar 2017, 20:04
by colinthefox
One is at the rear (front of the van) end of the cylinder head. This is the "normal" oil pressure switch which is .3 (or is it .03?) bar I think. The switch contacts are closed when there is no oil pressure, and open when there is a small amount of oil pressure.

The other is in the oil filter/cooler cast adaptor. It is the "buzzer of doom" switch, which for a 1.9 engine is set at 0.75 bar. The contacts are open when oil pressure is low, and closed when the pressure rises to the set value. EDITED COS I GOT THAT WRONG.

The pressure setting should be stamped on the face of the metalwork which (helpfully) faces the engine, and can't be seen once it is in place.

I'm pretty sure they are fitted the way I've described. If it's wrong then the oil light will not come on with the ignition, and the BoD will shout above 2000RPM. In that case just swap the switches over!

Re: Oil pressure switches

Posted: 29 Mar 2017, 08:13
by IAN-H
thanks Colin
Ianh