Hi, just got a question about the drive belt tension. Is there some sort of hydraulic tensioner of some sort on the drive belt? After a mechanic changed my drive belt, I'm hearing soft pulsing humming noises I didn't hear before. The pulsing noise rate increases with RPM.

Also when I have the air conditioner on and start accelerating, I hear small whining noise as well (also not heard before).

When I press on the belt, it feels very tight but if there is an automatic tensioner, the problem might not be a tight belt.

Thanks!

 

There's a spring loaded tensioner at the bottom of the engine. It is not adjustable. If the new belt is slipping maybe your mechanic installed the wrong size belt.

 

I don't think it's slipping because I'm not hearing any squeeking noise, but I think the belt is too tight. I'm just worried because it might be causing premature wear on the water pump/alternator/AC bearings.

 

I think the belt size is correct as well. I can't exactly remember the part number but it was something like 6K1795 or something similar. I've seen an Evo 9 owner using the exact part number form the forums and had no problems with it.

 

Well, you could get an OEM belt from Mitsu and have it installed. After that, the only other thing to do is try a new tensioner.