viscous fans

[tonyppe]

hi all
just recently my cars temp has started to creep over the half way. as soon as i drive off it shoots down, and levels out when moving. im not loosing any water and it doesnt mis-fire on startup or anything like that.
is this the sign of the clutch going in the fan? what can i do to check?

cheers ya'all ;)

[Simon]

Very likely, when the temp guage shows halfway, pull over, switch off, and try turning the fan by hand, if it turns easily, then the viscous needs replacing.

Moving this to the tech section too BTW!

[Brianmoooore]

Or even just listen before you switch it off. A locked up viscous fan makes quite a roar when you rev the engine.

[Simon]

Or even just listen before you switch it off. A locked up viscous fan makes quite a roar when you rev the engine.

Locked up fan would cause over-cooling though wouldn't it?

[gazm3]

Si,

Would a U/S fan cause a cylinder head?.

Cheers Gareth.

[Brianmoooore]

[

Locked up fan would cause over-cooling though wouldn't it?

Locked up when it should be, I mean. A duff one will still be unlocked.
Still shouldn't over cool with a permanently locked coupling. Thermostat sets the engine running temp.

[Simon]

Si,

Would a U/S fan cause a cylinder head?.

Cheers Gareth.

Sorry, Gareth are you asking would a broken viscous cause a cracked cylinder head, if so, then yes, if the engine is left to run dangerously hot.

[gazm3]

What do you think Brian would the fan's death cause a cracked head?.

[Brianmoooore]

Fan's death won't directly cause a cracked head, but it certainly will if you cook it. M20B25s don't take kindly to being overheated.
We're talking well into the red zone, though.

[gazm3]

Thanks gents.

[tonyppe]

cheers you lot,
when i take it home later ill do what you have said.
so will it be really hard to turn when its at normal running temp? or will it just be noticeably harder ?

[Simon]

cheers you lot,
when i take it home later ill do what you have said.
so will it be really hard to turn when its at normal running temp? or will it just be noticeably harder ?

When the engine is cold there should be little resistance, as it passes the halfway mark, there should be resistance in the fan.

[tonyppe]

i think its on its way out lol
is there not some sort of clip that would lock it into solid mode in cases where the fan is starting to do this?

[Brianmoooore]

Good second hand fan complete should only be about £10 and it's easy enough to change. (Unless some half witted wa**er has Loctited it on!)

[E30BeemerLad]

what's the deal with the viscous unit and storage.
reason I askesd was that I had a good second hand unit I was gonna sell, but I believed that if you don't store it upright then the fluid leaks and buggers it, so i never attempted to sell on account of the fact i would end up laid flat in postage.

Is that a load of bolleau?

[Brianmoooore]

They should always be stored on edge, but AFAIK, it's long term storage,not a few weeks.