Pranged the underside of the car on some raised ironwork (gate stop) on my mate's driveway and ever since every time I turn the heater on there's a godawful rattling noise which is VERY loud both inside and outside the car!

 

Ordinarily I'd wait til the car goes into the garage to get this checked out but as it's cold out, it's fairly urgent not only for heating but the windows keep misting up too (due in no small part to the bad seals on the door windows!).

 

Anyway, long story short I was going to have a look myself tomorrow to see if its anything I can fix myself but have no idea where to start!! Would anyone be able to point me in the right direction in terms of what to look out for and where? The noise is emanating from the offside front...I think this ties in with where the AC unit is?

 

All help welcome!!

The air con pump is on the nearside front - but if you clonked that then when you turn the heater/air con on the you may have damaged the internals of it, it has a clutch on the pump so it will spin freely when the engine is running but once air con is turned on it will engage.

The air con pump is on the nearside front - but if you clonked that then when you turn the heater/air con on the you may have damaged the internals of it, it has a clutch on the pump so it will spin freely when the engine is running but once air con is turned on it will engage.

 

Sounds like it could be the culprit as it does sounds like a loose fan sort of rattle/noise. Is there anyway I could fix this myself?? I'm not overly mechanically minded but I'm a dab hand with a screwdriver! lol

Sounds like it could be the culprit as it does sounds like a loose fan sort of rattle/noise. Is there anyway I could fix this myself?? I'm not overly mechanically minded but I'm a dab hand with a screwdriver! lol

 

Hi matey, I would be very surprised if you have damaged the compressor as it is higher than both the anti roll bar and the subframe! however it does sound like an issue with the compressor though from your description and is maybe just a coincidence.

 

Try when you switch on the heater ( auto) then press econ below to see of the noise stops, if it does then the compressor is the culprit and most likely not your off roading ( gate stop).

 

You could always take out the air con fuse to stop the compressor engaging till you get a chance to sort it properly.The fuse is located in the black fuse / relay box on the front of the passenger side inner wing under the bonnet, it is marked on the top of the lid which fuse it is.

 

 

Jeff TT

Thanks for the advice Jeff. I think it may be something else though only because the noise comes on even when its just the demister on (in which case I don't have the econ option).

 

In any case I'll double check in the morning and try removing the fuse also and see if I still get use of the blowers albeit without any decent heat!

Thanks for the advice Jeff. I think it may be something else though only because the noise comes on even when its just the demister on (in which case I don't have the econ option).

 

In any case I'll double check in the morning and try removing the fuse also and see if I still get use of the blowers albeit without any decent heat!

 

the demister uses the aircon compressor. If the noise stops when you hit the econ button then its an issue with the compressor. (econ switches off the compressor, all other settings use the compressor)

 

Have you had a quick visual checkk at the compressor belt/pulley area ?....Im surprised you've damaged that, due to its location, but It can only be that really.

Edited December 23, 200916 yr by Yowser

vig they are talking bout the air con compressor fan which is in front of the radiator, take off the headlight panel and have a look in there but turn on the heating/air when u do.....

vig they are talking bout the air con compressor fan which is in front of the radiator, take off the headlight panel and have a look in there but turn on the heating/air when u do.....

 

no, talking about the Pump(compressor)

 

The fan only comes on at around 98degrees with aircon on, and about 104degrees with aircon off.

no, talking about the Pump(compressor)

 

The fan only comes on at around 98degrees with aircon on, and about 104degrees with aircon off.

 

ah ok, didnt think the pump would make a fan like noise tho?

ah ok, didnt think the pump would make a fan like noise tho?

 

The compressor bearings when failed make this noise, the pulley free wheels on the compressor until energised and then locks the pulley and compressor shaft as one and hence turning the compressor internals, this is when the noise will occur if the pump bearings have gone, and by the way the bearings I mention here are not the shaft bearings but the ball bearings which move within the compressor screw section to compress and pump the aircon refridgerant around the system, by removing the air con fuse it disables the pulley clutch but allows the heater to function as a normal non aircon unit, same as when you press econ.

 

 

Jeff TT

The compressor bearings when failed make this noise, the pulley free wheels on the compressor until energised and then locks the pulley and compressor shaft as one and hence turning the compressor internals, this is when the noise will occur if the pump bearings have gone, and by the way the bearings I mention here are not the shaft bearings but the ball bearings which move within the compressor screw section to compress and pump the aircon refridgerant around the system, by removing the air con fuse it disables the pulley clutch but allows the heater to function as a normal non aircon unit, same as when you press econ.

 

 

Jeff TT

 

ah got ya.

Well I'm very baffled now! I tested the AC/heater as suggested and....nothing! Not a squeak! It was very VERY loud yesterday and the car hasn't moved since I parked up on the drive. I haven't taken it for a drive yet so not sure yet if it's a problem that only appears when the engine is warmed up...otherwise can't think what it is. Would the cold have affected it in anyway? Certainly sounded like a mechanical problem so I wouldn't have thought so. Not sure now whether it's miraculously fixed itself or if it's gotten worse and past the 'noisy' stage?!

 

I did have a look under the car and can't see anything out of place (to my eyes anyway!) but there does now seem to be a small oil leak around the gearbox area. As I was using the standard jack I couldn't get far enough under the car to see exactly where it was coming from but it's about midway between the front two wheels and behind the axle...if that makes sense? Small but regular drops (every 10secs) of dark black oil...I figure this has to be down to the 'off roading' but doesn't seem too severe so I guess just checking oil levels til I can get it looked at should suffice?

 

I should add that there was no oil on the drive until I started the car so seems to only leak when engine is running...