Oil and Temp warning lights

I have recently bought a Mk1 1.8 Gti, which I have just M.O.T'd and got on the road. While I spend some time and money on my Scoob
The oil and temp warning lights have constantly flashed since I got the car.

I have done a full oil change on the car when I got it. Once the car is up to full running temp (on tickover) the light goes out, once underload it starts flashing again.There are no nasty noises coming from the engine. I assumed that it is the oil pump, as it only only happens when the oil is thick or the engine is under load. If so how difficult/easy/exspensive a job is it to change, or is there easier/cheaper options to try first.

There are no problems with the cooling system on the car that I can find. The fluid is as clean as it can be, there are no air locks and the fan kicks in at the correct time.

Thanks in advance for any help/ideas

Anyone?

Although the warning lights are notorious for giving false alarms its best to actually check the oil pressure with a gauge. These can be got from ebay (search for VDO) or try a friendly garage.

You could try some new pressure senders just in case. Or rap the instrument cluster with your knuckles this sometime works and proves that its probably duff electronics.

Never done it myself but changing the pump is relatively straight forward but a couple of the sump bolts are partly hidden by the bell housing and the new pump must be torqued up to the correct tightness.

A blocked breather (the lump on the cam cover with hose coming off it) can casue oil pressure problems.

The water temp gauge is also a water level warning. Check the sender on top of the expansion bottle.

If you do a search there are loads of topics on these problems.

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