Viscous fan

[ETERNITY]

The viscous fan comes in after 5 mins of driving

It’s stays on and drowns the engine note and slows down the performance and deaccelaration is prolonged

It’s a loud whining sound as the engine rpm increases

I Have changed the radiator and fan coupling/clutch and still have the same problem

I have bought a thermostat but not changed yet because I tested the previous one and it seems fine but was Checked at boiling point (kettle)

Puzzled?

[paultv]

If your temps are good, maybe the old fan coupling was shot, and the new one needs running in, they tend to be "hard coupled" for a week or two depending on usage, then they loosen up and only spin when hot.

Cheap eBay viscous fans are known not to perform correctly in our cars best to buy OEM if possible.



Paul

[ETERNITY]

I bought a BGA (bullsye)

Thanks Paul

[arrisbmw]

thats strange never heard mine, before or after fitting a new viscous coupling.
my old one was knackered try the rolled up magazine test.

I suppose if your worried about performance , electric fan gotta be the way to go,

[ETERNITY]

Performance is affected because there seems to be a lag when the fan is on and making that jet noise

Theres a fault that I can’t figure out and neither can the mechanic

[paultv]

Is the car sounding normal when run without the fan belt for a quick test?

Paul

[ETERNITY]

Haven’t tried that yet

So undo the fan belt right and run it

[martauto]

Is the car sounding normal when run without the fan belt for a quick test?

Paul

Good way to check Paul !

Mart.

[ETERNITY]

Haven’t tried that yet

So undo the fan belt right and run it

[martauto]

Haven’t tried that yet

So undo the fan belt right and run it

You dont have to go very far and you will know pretty soon.

Mart.

[paultv]

Yep, loosen the alternator, get the belt off, you can finagle it over the fan and get it out - then start up and listen. This will take the viscous fan, water pump and alternator bearings out of the equation -

I fitted a cheap viscous a while ago - the car sounded like an F1-11 taking off and it refused to loosen up, so bought a Behr which cost twice the money but worked fine.

Paul

[arrisbmw]

i would not drive the car without the water pump will overheat very quickly. as no coolant is being pumped around

[M3KUK]

Yes mine is noisy too, cheap one off ebay, would buy a named brand next time.

[martauto]

i would not drive the car without the water pump will overheat very quickly. as no coolant is being pumped around

Like Paul said, it`s only for a few seconds and you dont even have to drive it, just see how it is without it.

Mart.

[ETERNITY]

Yep, loosen the alternator, get the belt off, you can finagle it over the fan and get it out - then start up and listen. This will take the viscous fan, water pump and alternator bearings out of the equation -

I fitted a cheap viscous a while ago - the car sounded like an F1-11 taking off and it refused to loosen up, so bought a Behr which cost twice the money but worked fine.

Paul

I just did the same and mine and replaced it with a behr and it still sounds like a jet. The sound and interference with the performance is annoying.

The sound is loud and I can feel a drag from the fan

Not sure a¤” where to go from here.

[paultv]

it will take a few days to loosen up - they are pretty sticky out of the box

Paul

[ETERNITY]

Ok hopefully engine noise will go back to normal and I can enjoy the m20 note