Strange Noise When The Cooling Fans Come On

[jamesm]

I am totally mechanically inept so looking for any ideas on what might be causing this.

When the cooling fans come on, there is a loud constant rattling DDRRRRRRRR type noise. It spent the entire McRae Gathering weekend doing this.

It isn't coming from the fans themselves, which are free of obstructions and seem to work fine. The noise is coming from inside the section at the front of the engine to the nearside, next the belts, as per the arrow on the photos below.

The car itself runs and drives fine.

Any ideas anyone?

[euan_r]

sure its not from the fan as it could be fan bearing. was that you outside the banbary premier inn that was having an inspection of it?

if it wasnt only when fan kicks in i would have said cambelt idler or tension pulley. definite no no to fix if you dont know what your doing.

i would try spraying some wd40 into fan first myself then if that cured it follow up with spray of white grease.

other idea would be to see if noise only appears when air con is active as second fan only runs when this is on. (well on my classic anyway)

[jamesm]

sure its not from the fan as it could be fan bearing. was that you outside the banbary premier inn that was having an inspection of it?

if it wasnt only when fan kicks in i would have said cambelt idler or tension pulley. definite no no to fix if you dont know what your doing.

i would try spraying some wd40 into fan first myself then if that cured it follow up with spray of white grease.

other idea would be to see if noise only appears when air con is active as second fan only runs when this is on. (well on my classic anyway)

Aye that was me. Was it you with the red Wagon?

Still no wiser on what is causing it so it is getting looked at tomorrow. Still convinced that the noise isn't coming from the actual fans, but from something further back. It is only when the fans come on, and it seems irellevant to whether the aircon is on or off.

I have noticed that there is a bolt missing from the coolant bottle mounting. I wonder if that has somehow gone somewhere it shouldn't!

[euan_r]

no classic silver saloon.

sounds like it is something with first fan then. you could unbolt fan shroud and see if anything falls out. these seem the first to go rusty on classics but you should be ok with newer car.

[jamesm]

no classic silver saloon.

Ah yes. The red wagon was parked on the other side of me.

[t3hWIT]

Did you have any work done to the car recently? I'd check in the fan shroud to make sure there's no debris, then start wiggling parts in that area, specifically the coolant reservoir and the cam cover.

[jamesm]

Did you have any work done to the car recently? I'd check in the fan shroud to make sure there's no debris, then start wiggling parts in that area, specifically the coolant reservoir and the cam cover.

Full service 14 days ago. Is going back to the same place so we will see if they have managed to get anything stuck where it should't be. I have poked, prodded and wiggled everything, but still makes the noise. Will find out tomorrow I suppose.

[t3hWIT]

It's probably something simple, but yeah I would recommend taking it back to the place who serviced it. I can't think of anything in that location that could cause a noise like that unless there was something in the fan shroud.

Edited September 4, 2008 by t3hWIT

[colin_ross]

Full service means a cambelt and that means they took the rad out.

I'd be looking for foreign objects in or around the fan, loose bolts in the area and witness marks on the blades to see what it's hitting on.

Just because it's not making the noise when you spin it by hand doesn't mean it's not sucking something in when there's more airflow.

[johnnyr6]

It could be your coolant bottle is slightly loose and rattling whith the vibration from your fans.

Or maybe not.....

Johnny

[t3hWIT]

Full service means a cambelt and that means they took the rad out.

I didn't know what he meant about full service. A lot of times, when removing the cam covers, the nut on the back breaks loose. If that happened on the OP's, then the cover could possibly be loose, but I still don't see how the force of the fans would be enough to make it vibrate.

[kookamunga]

i heard your car at the gathering and it sounded like fan bearings or something touching the fan blades to me

[richscooby]

Hi

I was stopped beside you going into the test track at Warwick, and it definately sounded like the fan bearings.

Even my mate (whos not at all mechanically minded reckoned it was the fan bearing )

Good luck sorting it out,

Richard

[jamesm]

Well, mystery solved.

Despite sounding like it was coming from further back, it was indeed something getting caught in the fan. The connector cable for the fan itself had worked loose and the air was forcing it onto the blades when the fans were going, but not when I just turned the fans slowly myself.

So simple fix with a bit of tape in the end and a big thanks to Greers for sorting it out there and then whilst I waited.