Hello! I bought a used GL450 at a good price a few weeks ago and have already had to sink a fair share of money into it but I am having a problem I cannot figure out. I just had the local mechanic replace the tensioner pulley, idlers, belt and power steering pump. Before replacing these I was hearing what I thought was a bad bearing and the steering was not working correctly and noisy so I was thinking that's where my problem was. My steering is working fine now but I'm hearing a knocking coming from right around (or maybe below) the where the new pump is. Also, maybe coincidence, the A/C was FREEZING two weeks ago and now isn't getting very cold, if at all.

The engine is also missing slightly, which I only notice at low idle. Not sure if that is related too. Otherwise, power and acceleration is great.

The video attached will give you an idea what it sounds like.

Help!

 

 

 

Are you sure it didn't seize a few days ago? The belt may have survived for a little while - in other words, it took a little time for the belt to shred, constantly grinding across a non-moving pulley. Hindsight is 20/20, of course, but as soon as the A/C stopped working, it would have been a good idea to give the system a visual once over - probably could've avoided the shredded belt. Check everything real well to make sure the belt didn't damage other things.