Tired old topic - radiator fan failure

 

Apologies for posting what has probably been posted many times before but there was only so much trawling through historical posts I could cope with.

 

I recently bought an E46 (April 2000) 318i saloon. A couple of weeks ago, a plastic cooling pipe split, so the engine dumped all the coolant on to the road. I got the car home safely and had the pipe and coolant replaced. So far, so good.

 

Now I find that, whilst the engine gets up to temperature quickly and stays at the halfway mark initially, after about 10 miles, the needle will suddenly fly up to and beyond the red. At no point does the (electric) radiator fan kick in.

 

Steps taken so far:

 

1. Split pipe replaced, system flushed, coolant refilled (by local garage)

2. Thermostat removed. (Not yet replaced)

3. Coolant temperature sensor replaced.

 

There is no evidence of water loss or air locks that I am aware of. It's getting mightily hot under the bonnet, so I would have expected the fan to have started, as I believe it will only start once reacing a given temperature.

 

Is there a simple way (i.e. no specialist tools) to test the fan? Can I force the fan to start when the engine is cold/not running? I can see three wires going into the fan assembly. If I unplug that connection, can I put a battery across the connections to try and fire up the fan? If so, which terminals do I need to connect to? Can I/should I wire the fan to run constantly?

 

I don't want to be replacing parts if they're not faulty but am now nervous about driving the car because I'm constantly looking at the temperature gauge.

 

Yours nervously,

Steve

(New-Age Luddite)

The fan is electric, mounted on the engine side of the radiator.

The heater now pumps air out that makes the cab space slightly hotter that Hades.

The car wasn't run with no coolant, although my 30 mile journey home took 6 hours, going a couple of miles at a time, stopping to cool (before the needle rose), topping up and continuing.

 

It sounds like I did the damage trying to get home. I, too, am concerned that the head is buggered. That being the case, I fear a skimming operation or a replacement . either way, I also fear a humungous bill.

 

Made a single entry in my diary after posting this. Said simply, "Bugger".

 

I now have a new naive issue; how to refit the serpentine belt? For the life of me, I can't see how to loosen the tensioner. The engine is a 1.9 petrol manual, M43. The tensioner is below and to the left of the alternator. It seems to have 3 fixings: 2 socket screws & a 13mm hex bolt, bottom left. I can't move the socket screws at all and loosning the 13mm bolt seemed to do nothing.

 

Any and all advise gratefully accepted.