Golf mk1 cab 93

Hello guys
I have problems on my golf, the oil temperature reaches 98- 100 degrees and gives a sound from the cluster and flashes in the oil lamp. Have just changed the motoroile, Stadif the same. There is heat exanger on. Do not know what problems are. Nofle who has suggested.

What type of Viscosity of oil did you use?
What type of filter?
It is possible that you knocked the wire off your High Rev low pressure switch on the Oil Filter Flange.  It is the white sensor on the filter flange with a single wire on to covered by a rubber boot.

I use 10/40. oil filter aftermarket.
sensor looks fine and wire too.
I can drive the car in longer distance and suddenly oil lamp blinkes and a sound comes too. How about the small sensor on the filter housing. 

REplace the low pressure high rev switch it is white usually on the oil filter flange.  

Check the wire on it and tighten it clean it if it is corroded or greasy

Then I would be looking at getting the oil pressure tested as the pressure relief valve on the oil pump can go wonky and the pressure can drop….

Is it one with rubber on. I Got only to sensor on the filter flanger. One with rubber on and second is where the wire shoe is slider on. Should I Change both of Them. 
About Oil pressure, Can I take one of those 2 sensors put and messure the pressure. 

The oil light and buzzer is sounding because its reading low oil pressure, the buzzer will only come on when revs are over 2000 rpm.

Change both sensors and if you are still getting problems then it's un bolt the sump and replace the oil pump, prime the new oil pump, fit a new sump gasket and a good time to up grade to a rubber gasket and refit the bolts. The hardest part of the job is getting to the 2 bolts near the gearbox as there is not much room and they screw into aluminium so it's really easy to cross thread them.

Oil filters you are best getting genuine VW or Mann filters, both around £3.

Oil pressure sensor on top of the oil filter is the high pressure (White)
Oil pressure senor on the side of the head is low pressure (Blue or brown)
 

Ok i Will change those 2 sensors on filter flange and the one on side of the head. And see Will it helps. 
Many thanks for now, i Will Update 

Hello there
I changed all of 3 sensors but i havent driven the car in 2 weeks couse rain waether. I mounted a afremarket Oil pressure gauge, in sted of the White Oil sensor. When cold shows 6 bar, when temp is 80 degrees, Oil pressure shows 0 bar. Så im not sure If the gauge is one I Can trust.

Has measured the oil pressure when it is cold 4.5-5 bar, at 80 degrees at idle 1 bar, at 2000 rpm 3.5 bar. Seems it sounds fine, but it still lights in the oil lamp and gives sound. So I do not think it can be oil pump.
Oil filter is from bosch 0451103033.

Have you checked your cluster connections, as in Beef up the Ground, by splicing wire to the brown wire and running it to frame behind the cluster?

The Speedo has the oil warning circuitry in it, and the connections to the cluster may be wonky.   if you have the Cabriolet type of connections there are tutorials in the Archive section on how to improve your cluster connections.

Good earthing to the engine/tranny, and frame are also worthy of cleaning and or replacing.

The Head to Coil Bracket ground is another.

I have not checked ground points behind cluster. Could possibly create a new wire to ground about the cluster and put the wire on the ground wire on the cluster. Yes I have a cabriolet from 1993.