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View Full Version : 525i Touring MPG and running temperature



fran9r
05-03-2015, 11:24 AM
Hi everyone, I wonder if you could help me please.

I have a 1992 M50 engined non-vanos 525i touring, which I have just bought and had a clutch fitted.

I'm really enjoying it, although maybe need to improve the handling one day. For now, I just want an idea of MPG you guys would expect, and also this morning (raining heavily) the temp gauge stayed quite low, and even went back to the blue a couple of times. Also, the heater dosen't seem to get hot -wonder if the thermostat isn't doing it's job? However, on the way back it seemed to sit in the middle temp, but it was a lot hotter.

Any thoughts would be appreciated.

Frank87
05-03-2015, 06:15 PM
You may be dealing with:

- Fan clutch always on = excessive cooling
- Bad thermostat indeed = excessive cooling

If you do not know anything about the car's past. A belt / pulley / pump / thermostat / coolant job would be useful and is very easy on an M50 engine.
The fan should not be cooling the engine when the engine isn't warm.

632 Regal
05-03-2015, 07:16 PM
I just want an idea of MPG you guys would expect, and also this morning (raining heavily) the temp gauge stayed quite low, and even went back to the blue a couple of times. Also, the heater dosen't seem to get hot -wonder if the thermostat isn't doing it's job? However, on the way back it seemed to sit in the middle temp, but it was a lot hotter.

Welcome aboard!

You could have an air pocket in the cooling system causing the heat issue. Whenever you bleed the air out of the cooling system you need to have the heater on full temp, some say to have the blower on full also. Without it you will never rid the cooling system of air.

Winfred (who the **** is Winfred?) says get the front of the car up, like ramps to get the air to the front. Otherwise it takes hours to do it right.

Fix the above before even messing with the thermostat.

Maintenance does include waterpump, belts, hoses along with draining and refilling of all fluids (brakes, rear end, PS, with special regards to transmissions). Fortunately you will then know how to get the air out of the system.