I changed my crank pulley w/ an Empi aluminum one, and my alt pulley w/ a chrome one (Scat?).
Everything was great until I had driven a few miles. Then a noticeable noise started. While driving I thought I had sprung an exaust leak. The sound changes w/ engine RPM. Louder/higher pitch at higher RPMs.
When I got home I noticed the noise was coming from the engine compartment, though it still sounded like an exaust leak. I sealed up each tail pipe (stock exaust) one at a time and noticed no change in the sound. I listened at each rear tire and the sound was obviously coming from the engine compartment and not the heads or front exaust flanges..
Could this sound be coming from my new pulleys? Would a fan belt adjusted too tight cause an engine noise?
When installing the crank pulley I first installed it w/o the spacer that came w/ the pulley. There's no mention of the spacer in the install instructions. The spacer looks like a small steel ring that just fits around the crank nose w/ a small bit missing to fit the crank's key. After getting the crank pulley on, I could see that it didn't line up w/ the alt pulley (too far into the case). So I removed the pulley, installed the spacer and everything was almost perfectly inline. I didn't think the slight (1 or 2mm?) misalignment would be a problem. This was installed yesterday w/ the stock alt pulley. No noise w/ that combo.
Today, I also had to use a gear puller to get the old (original stock?) pulley off. When installing the new chrome alt pulley I noted that the number of shims was different than the stock config. Instead of four shims between the pulley halves I had to drop it down to two to get the same belt tight enough. So now there are two shims inside and five outside the pulley. The noise started a few miles after finishing this install today. Nothing else was done to the engine today.
I'm going to try running the engine w/o the fan belt (just for a few seconds) to see if the sound goes away.
Has anyone seen this before?
AshMan