Which Viscous?

[jas025]

After performing the newspaper test I knew that I had to swap the viscous fan but there's 2 different types.

Any idea how to tell which one I've got before you remove it?

I shoved my phone up close to it to take a picture if this helps at all?

Cheers in advance!

John

[Brianmoooore]

BMWs use two sizes of viscous coupling in my experience. E30s use the smaller diameter of the two.
IMHO, the so called newspaper test is close to meaningless. What makes you think you need a new coupling?

[jas025]

BMWs use two sizes of viscous coupling in my experience. E30s use the smaller diameter of the two.
IMHO, the so called newspaper test is close to meaningless. What makes you think you need a new coupling?

It overheated in traffic, I've had all the sensors replaced and while it sat on the drive the fan didn't really cut in, just freewheeled. I've also got the instrument cluster out at the moment so I'm going to make sure that both nuts are tightened so hopefully the temp gauge gives as accurate a reading as possible.

I'd like to have full confidence in how it runs - especially if ever Mrs Jas uses it - the temperature gauge is there for decoration - if it did overheat she wouldn't do anything until it broke.

So perhaps it's a little pedantry on my part but I'd at least like to eliminate this from the equation.

[Brianmoooore]

If the temperature climbs with the engine running and the car not moving, and the gauge is approaching the red section, you should be able to easily hear the fan roar if you rev the engine. If it doesn't, then the viscous coupling is due for a change.
The roar from the fan is loud and unmissable.