Oil Pressure Switch, ideas??

[Brin]

Hey guys, just wondering..

What would cause the oil pressure switch to blow on my VR V6?

It happened about a month back now and I still have no idea why. I know that earlier that day, I flushed and bled the whole engine out whilst replacing the thermo and thermo gasket..

Topped up coolants etc and I had my oil pressure light flickering on and off the whole way to Maccas.. I checked the oil which was at a fine level, but then later on that night the switch blew, every time you tried to crank her it spat oil all over the engine and we had to get the VN towed as no oil pressure = disabled fuel pump.

Funny thing though, when I replaced the oil pressure switch the next day, I didn't need to top my oil up at all. I thought that it may have been diluted but wasn't...

So yeah, what could have blown this? Would flushing my engine out with the hose have broken a gasket and then raised the oil pressure enough to blow the switch?? I dont know....

Thanks in advance guys......

[immortality]

i've had the oil light come on after washing the engine also, if water gets in the top of the pressure switch it doesn't like it. the seal is only desinged to prevent splashing water etc, not pressurised spray mine came fine after a few days, i know i had oil pressure as i got a pressure gauge not ever seen one "blow up" before. thats a first for me

[Brin]

Hmmmn ok at least I know that my engine washing may be a cause now!

Thats weird, immortality. The light was flickering on and off, not constantly though. The car just stalled that night, every time you tried to crank her over a hella lot of oil came outta the switch, and it kept blowing the fuel pump fuse.. Replaced with a VH switch for the time being, although it has a different plug ontop for the sensor so i've been checking my oil levels alot lately.. Haydz just told me a new plug is 12 bux across the road at Peps so i'll be gettin that tomo.

[Brin]

Basically, I know the switch was "blown" cause

1) it kept spurting out large amounts of oil, and..
2) if the engine does not sense oil pressure, it disables the fuel pump.

We had her towed home meaning to put the spare vl pump in there, but replaced the switch first and she ran fine... haha.

[immortality]

when i washed mine it flickered for a bit and then just stay'd on. all good now

[forhuksake]

its because water gets into the switch and creates a problem, also if you hit it with a pressure hose that can make it go as well.

[kopper69]

Can you provide some photos? Where abouts had it blown off. The thread into the housing is fairly deep and would be quite strong, there would have to be a crack or some mechanical damage to cause it to blow. The oil pressure isnt high enough to go popping them off.

Normally the fuel pump is supplied power through a different path, and if this fails it can also be provided through the oil pressure switch, meaning the car should still have started without the oil pressure switch.