Crank Aux Pulley! Please Help!
After what I thought I had diagnosed as a faulty alternator bearing, I am now 100% positive that the rattling sound I am getting is nothing to do with the auxillary belt tensioners or anything that is run on the aux belt.
I am getting a rattling noise when accelerating hard, more so in a high gear and low revs, in other words, when the engine is under load.
I honestly thought that this was a faulty tensioner or the bearings in the alternator that had gone, and I was sometimes getting a squeak when starting the car on a cold morning, similar to a fan belt slipping.
So this is what I done - I changed three aux belt tensioners and the belt itself. The noise was still there. Today, I took the aux belt off the car and took the car for a drive (what I should have done ages ago). The noise was still there when accelerating.
I have now eliminated everything from the aux belt run, apart from the crank pulley (auxillary), which I noticed was bouncing up and down when the car was idling, however, when the engine was revved, it smoothed out and stopped "bouncing up and down".
This has been discussed before, and as far as I am aware the crank aux pulley has got a damper on the back of it to allow it to oscillate, so maybe this is normal, but the noise that is coming from the engine isn't!
Any other relevent info I have is that I had a recon' engine put in last summer, I have also fitted new engine mounts and of course all auxillary belt tensioners. It may also be worth noting that when accelerating hard from a standstill in the wet weather, I get a squeel from the aux belt, but no battery light. The rattling noise does seriously quieten down though when driving in the wet, as if the water from the road is lubricating the pulley bearing, maybe?!?
Apologies for being so long winded, but that is the best I can explain it, and the noise is driving me absolutely mad, so any help will be greatly appreciated!
Alfa Romeo 156 3.0 V6 24v Lusso (2000)
Lancia Delta HF Turbo IE (1991) - Rust In Peace !