Rattling from front of engine

[sk712]

Hi there,

Just hoping if someone could help me out. I had a rattling noise coming from the front of my M20 and was sure it was the altenator as it soon died after this rattle appeared. I replaced it with a reconditioned altenator and the rattle was gone when I started the car but when it reappeared once the engine got up to temperature. It definately sounds like it is coming from the alternator area. I did put a screwdriver on the altenator to listen for anything strange and it seems to be humming away fine. Just wondering if there is something else that could be causing it or is the reconditioned alternator a dud? The water pump was replaced about a year ago. Any suggestions would be greatly appreciated.

Cheers.

[stonesie]

If it was a cheaper water pump it could be dying already, it could also be the viscus unit that's on the front of the waterpump.

Run it upto temperature so the viscus locks and see if that makes a differance to the noise, all the air moveing might mask it though so check for play in the fan too (with the engine off).

[bm_boy]

id second the waterpump mate, usually the impellor breaking down and rattling about, will get worse the more you drive, does it overheat or has it overheated since the rattle started sounding? if so it could be the waterpump.

[sk712]

No it hasn't overheated & the water pump is only a year old. I'll replace it if that's the only possibility I suppose.

[cro320]

check timing belt adjuster, had the same problem...also worn alternator bearings can make sound like that

[E30Gheko]

I had a strange rattle coming from mine and found that one of the fan blades was catching a coolant hose ever so slightly.

[sk712]

Thanks for the replies lads. The noise only occurs when the engine is fully warmed up. Its a consistent turning noises kind of chinging sound if that helps. The fan blades aren't catching anything.