Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Noisy coolant fan 4/4

Can anyone help with a cooling fan issue. My 2001 4/4 black top Zetec has what I'd say is a noisy cooling fan which tends to run more often than expected. The dash temp gauge says the engine is cool but the fan runs anyway. I've had a new rad fitted last year but am wondering if I should have had the temp sensor changed as well.

Phil

If changing the rad made no difference, and its running a lot then the sensor is the next thing to look at. But are you sure that the gauge is accurate?

Dave,

I changed the rad because of a leak. I've become more aware of the noise of the fan the longer I've driven the car and compared it with other Morgans. Is the sensor a difficult job to change.

Phil

I'm looking into the same issue - frequent running of the fan on my 2005 4/4 (blacktop zetec) when fully warm. I'm not convinced the temp is high enough to require such a lot of "fanning" - gauge reading 105-110 max. Some other posts have suggested this is a "characteristic" of the black top zetec engined 4/4. If so, its a b. nuisance. The ECU, which controls the fan, apparently gets its signal from one of two sensors, one is in the thermostat housing and one in the block, but in the rats nest of cables everywhere, I can't really make these out. I guess its possible a malfunctioning sensor could fool the ecu into running the fan more than needed.

But - I have had a S/S manifold fitted, which gets quite hot, and eliminates the heat shield between exhaust and water rail/tubing. This may well be increasing the temperature of the circulating water. I have no leaks, all hoses are good, and I plan to carry out a full flush just in case.

A Mulfab rad would apparently make the car run cooler, but that is a high cost item and job, so I'm reluctant to even consider that until this issue is sorted out. Another option is zircotec coating of the manifold. But first I need the sensor/ECU issue checking out, which I now think is beyond my limited skills.

Any suggestions, or solutions, would be very welcome! The sensors are not expensive apparently, but it would be helpful to be able to identify them first - anyone with photos?

Nigel

Hi,

My 4/4 with black top zetec also has a Mulberry aluminium radiator, and standard exhaust manifold.

My coolant temperature is between 90-95C, along country roads.
The fan starts close at 100C.

It used to be 100-110C, before I tampered with the idle speed control valve, reducing it to 900 revs pr. minute.

The fan on my S2 Roadster cuts in, and makes a lot of noise, bit like a small aircraft, at an indicated 100C!
On the open road it is never on but in slow moving traffic it is on most of the time. When on the temperature stays nicely at 100C, so it works, but the noise....

Don't forget that thermostats get lazy and are a low cost item, so if opening the coolant system at all you may was well change the thermostat at the same time - I would recommend sticking with OEM parts as cheap pattern ones don't tend to have the same in use life.

You could go one step further and use waterless coolant too.