P38A Viscous fan woes

P38Seb · Monday at 21:14

I’ve just replaced the viscous fan on the P38. Yet the load roar noise is still present, and the fan appears to be running at full chat even when cold. There’s a LOT of air being blown by the fan.

I let the engine get up to temp and it’s still there and loud. Is it likely a faulty fan or am I missing something? The fan was a new unit from LRDirect as well.

@Datatek before you say to do the air con fan mod, I wanted to give the fan a try first..

biketeacherdave · Monday at 21:55

OK do the aircon fan mod

kermit_rr · 2024-07-02T08:11:47+0100

Run the engine for 5 mins. Stop the engine. Can you turn the fan by hand? Does it stop at soon as you let go?

Mark Piercy · 2024-07-02T12:07:25+0100

If it's a britpart unit they let go after a slightly longer time. The mahle viscous fan is better, not cheap but better

P38Seb · 2024-07-02T14:23:01+0100

I am stupid. Took it for a drive. Soon as I pulled away it was dead silent.

kermit_rr · 2024-07-02T15:09:02+0100

Glad you're sorted. They are good when they work

Datatek · 2024-07-02T16:21:58+0100

kermit_rr said:
Glad you're sorted. They are good when they work

It's just that they don't work for long and fail in a sneaky manner that causes overheating.

Grrrrrr · 2024-07-02T23:23:36+0100

P38Seb said:
I’ve just replaced the viscous fan on the P38. Yet the load roar noise is still present, and the fan appears to be running at full chat even when cold. There’s a LOT of air being blown by the fan.

I let the engine get up to temp and it’s still there and loud. Is it likely a faulty fan or am I missing something? The fan was a new unit from LRDirect as well.

@Datatek before you say to do the air con fan mod, I wanted to give the fan a try first..

Should roar on startup but quieten down after a minute or so. Shouldn't roar again unless it starts overheating. So fan must be seized and therefore a duff one.

Edit: just seen it quietens down after it warms a bit so all good.

kermit_rr · 2024-07-03T08:18:05+0100

With the engine off, if you spin the fan by hand (in the correct direction) it should initially be very stiff but start to get much easier after a few dozen spins. Should be very obvious

P38A Viscous fan woes

P38Seb

Active Member

biketeacherdave

Well-Known Member

kermit_rr

Very

Mark Piercy

Well fumbled member....

P38Seb

Active Member

kermit_rr

Very

Datatek

Well-Known Member

Grrrrrr

Technician, Bodgit & Scarper Ltd

kermit_rr

Very

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