HELP PLEASE: Oil Light Flashing

[Fletcha]

Daaa the light it mocks me. this problem has been the bane in my life now for about 3 weeks.
i will set the scene. my daily drive to work. about 20 miles each way ( i know thats a whole different issue) which takes me through huddersfield town centre, and the inevitable rush hour traffic jams.
all is well with the world until this moment. then the oil temperature raises above 90 degrees and the lights starts to flash. the car seems to be running fine, no rough idle or knocking, engine temp doesnt increase. and then with any little revs the light goes off.
currently solutions that i have tried are. new oil, new oil filter, new oil pressure sensor and finally a new oil pump.
currently nothing has worked and am now out of ideas and at the end of my wick i kneel down infront of the GTI forum and please can someone shed light on this.
my last thoughts are that it is a faulty earth, but i am yet to figure out why this would only happen above a certain temp.
please im starting to think that the light will start responding 'nevermore' to any of my fixes.

[LowlifeDubber]

Have you checked the pick up pipe in the sump for a build up of deposits?

Stick an oil pressure gauge in your oil pressure switch port and see if you have decent oil pressure.
The wiring to the switches get really brittle and can earth out intermitently might be worth checking the wire to both.

Have you got the correct switch in the correct hole?(assuming you have a low and high pressure switch on yours)

[GTIANNIVERSARY16V]

I didn't even know there was a oil light warning.......
That explains alot, i was leaking oil....it was empty....no warning light

[CM690]

I've had a similar issue with my MK3 1.4. The oil light did come on only when warm and wouldn't go out until about 4,000rpm. I got this looked at and in the end opted for a brand new oil pump and have gone through several oil pressure switches to try and sort it and the best I've managed to get it to was the oil light comes on when the car is up to temp never before and will go out at 1000 rpm. No idea why and I only have the one sensor port on my engine because I've searched high and low for it Good luck solving the problem though mate

[Fletcha]

well after a few chats with the engineering gurus at my work have come up with a new theory/ experiment. going to see whether after 120000 ish miles the engine has just worn out its tolerances, so at higher temps the viscosity of the oil isnt great enough to stay in the bearings at idle.
so a dose of 20w50 is the order of the day. * am aware that this probably isnt a good idea if its not. but meh that used to be the only oil available so it can like it.*
will report back with results.

[andy-gti84]

mine got 80k on it an has been doing the same mate. just cleaned all the points swiches etc an repluged main oil pressure swich an had been spot on now for weeks. not sayin iv fixed it but has worked fine up to now tho. gd luck

[CM690]

well after a few chats with the engineering gurus at my work have come up with a new theory/ experiment. going to see whether after 120000 ish miles the engine has just worn out its tolerances, so at higher temps the viscosity of the oil isnt great enough to stay in the bearings at idle.
so a dose of 20w50 is the order of the day. * am aware that this probably isnt a good idea if its not. but meh that used to be the only oil available so it can like it.*
will report back with results.

I use that oil too and it's helped a little

[Fletcha]

just to conclude this thread if anyone was wondering. 20w50 oil applied and blinking stops. its all gravey baby.
cheers for the help.