Hey guys,
Recently my 92 SC300 has been knocking. I don't understand why becuase the car has less that 100K miles on it. All I know is that I took the driving belt of and started the car and the knocking went away. This tells me that whatever is knocking is run by the driving belt (water pump, or power steering). Which one do you think is the the reason for the knocking and how much will replacing it cost?

 

Your timing might be off, I'd say get it checked at a competent mechanic shop or the dealer.

 

Well, if you took of the accessory belt and the knocking went away, it could be one of a few things. It could be that the engine is happy without any load on it at all. Did you throttle it at all? There have been others on the board who have noticed that the other accessories sometimes give off noise that can be mistaken for engine knock. Manually turn each pulley and see of one doesn't turn smoothly. While they all could potentially be the culprit, the tensioner pulley has been pointed out more than once. I had to replace mine. Look up tensioner pulley to find out which bearing you should use. I don't remember off the top of my head. It is a quick $5 part that can be swapped out in under 30 minutes. Since the price is so low, I would start there.

 

thanks your post really helped. I took the belt off again and took off the tension pulley. Its not too bad but there is a noticable sound when its manually turned. The alternator, fan, and water pump turn wihtout any hesitation but the power steering seems to also make noise when turned. I ordered a new tension pulley today ($25) and as soon as it comes in i'll install it. Hopefully I won't have to replace the power steering pump ($300+).

 

Try replacing the PS fluid with some good oil. The SC300 uses Dexron II. I've been using Maxlife ATF and PS fluid in mine. Pump out what is in the reservoir and refill. It may buy you more time and give you an idea of what needs attention if it quiets down. If not, atleast you replaced the fluid! What did you spend $25 on? The entire pulley wheel? The entire tensioner? I fixed mine by buying a 6203RS universal bearing and replacing the one in the pulley. $5 and a hammer.

 

The $25 was for the entire wheel including the bearing. I haven't put it on yet so i think i'll return it and just get the bearing instead.