ShawnmA4

Ive got a 1999 audi A4 B5 and when i first start up the car says the oil is already 250degress and when i drive it it will raise to around 300+ but the watertemp stays at normal temp. i just had to replace the timing belt idler roller cause the bearing went out in that and was doing some cleaning with some parts cleaner and i know the oil temp sensor is right between the crank pulley and ac pulley would it be possible i didnt completely clean off the cleaner and it ruined the senor? the car runs fine just seeing that gauge that high worries me.

Bobby Kinstle

That's probably a broken oil temp sensor. Normally on a cold engine, the water temp will normalize long before the oil temp, and it's certainly not 250 degrees when you first start it. I would try the sensor first.

tenspeed

It more probable that the sensor is fine. The sending unit supplies a varying amount of ground potential to the gauge. The lower the resistance, the higher the needle swings.

When you cleaned with the parts cleaner you provided another path to ground which causes the gauge to read high at start up. Unplug the electrical connector and and clean everything with contact cleaner.