Drurydad

I am having all kinds of problems with this car, a 1996 a4 Quattro. I was told the car just needed a wheel bearing which I fixed.
The radiator reservoir needs to be replaced which I have ordered.
The upper thin hose going into the reservoir was broken. I jb water welded it and it seems to be fine the car isn't overheating.
Now today the oil temp caught my eye. I has always sat right in the middle at 250
today it stayed moving to max 350. I was on the highway and in traffic trying to get over from the left lane. By the time I got over the car stalled. I waited a hr and she started right up. Oil Temp gauge starter moving high. I got the car home and it was at 275, any longer it would have gone to 350.
The radiator temp was high but not overheating. When the car stalled from the high oil temp the radiator didn't overheat.
What could cause this?
Oil pump shot would be my guess. Any other possibilities?
Thanks
Stephen

Prospeeder

Bad oil temp sensor. Poor connection, even. If the oil is really getting to hot, the oil does about 30% of the total cooling capacity of an engine, if the cooling system cant get rid of the heat, oil temp is going to go up. If the gauge moves anywhere past the middle its getting close to overheat. The gauge is programmed to go between a temp range of like 180-230 before it moves away from center. As soon as the gauge is moving, your talking 240+ degree coolant temps, thats border line overheat boil over, 260 is damaging the engine. So you probably DO have an overheat issue, weather its thermostat, radiator, fan ect need to be working.

Drurydad

thank you so much.
I have ordered a new reservoir tank, thermostat, oil sending sensor , radiator sensor, water pump and timing belt and hopefully with those things ordered this will get straightened out thank you so much for your advice.
Stephen

Prospeeder

Just to help, get a point and shoot laser temp gun. And you can get the car hot, and see if the upper hose is really hot and the lower is cold (like thermostat bad), or if the radiator itself has cold spots or no heat transfer happening it could be full of scale and junk. Even water pump impeller can crack and slip and cause it to run hot. Removing the thermostat and looking in and inspect the impeller.