BradBodsworth

Hi guys,

Any ideas what this noise could be?? 2003 model 3.2 supercharged....

GRRRR... is my car going to explode soon??

Brad

Velociabstract

I think you need a new supercharger pulley. At least that's what it sounds like to me.

Les

BradBodsworth

Hi Les,

thanks, you think the pulley or the pulley bearing?? Or am i missing something here? Not an expert on this kind of stuff...

fleishman

Kinda loud for just the bearing but it might be echoing around. Bearing is easy diy and a lot cheaper than a pulley. (can the clutch be rebuilt?) Is the supercharger engaging normally?

Velociabstract

I think it's the pulley. If you take it off it's easy to tell whether it's the bearing or pulley. My pulley wore out and started rattling similar to yours. I put a new bearing in it first, wasn't the bearing. The metal straps attach to rivets. Sometimes a strap breaks (fix it now) other times the straps wear at the rivet causing some looseness. You can drive with it like that a while but if a strap breaks it could be expensive. If it's a bearing, and it could be, take the belt off and turn the pulleys by hand. Usually it's the idler or supercharger bearing if its a pulley bearing. The way to tell if its the straps is to take the supercharger pulley off and twist it in your hands. If it makes noise, it's a time bomb. Here's what mine sounded like.
Les

BradBodsworth

Hi again guys, alright, replaced SC bearing, its not that. still makes the noise. Starting to think its come more from the left bank, (non battery side) any more ideas?

Velociabstract

The first bearing to go is usually the idler because it spins faster than the rest.

Les

BradBodsworth

Hi Les, thanks for that, forgot to mention, started car up with serpentine belt off and it made that noise still.... now im really worried. through all my reading been starting to think timing chain issues??

Velociabstract

I don't know what to say, if it were a timing chain guide or tensioner I'd think the timing would be jumping around quite a bit. It did on my old M110. On my old american iron you could hear the stretched chain slap the cover from time to time. My other guess would be a valve spring failure. Frankly, I don't know. Keep narrowing down the area the noise is coming from. Here's hoping it's not expensive.

Les

Supgee

kinda sounds like a valve running without oil..
My m119 engine had an issue where one of the cam oiler tubes had broken inside the valve cover and resulted in a lifter running dry.

Im not sure if the m113k engine uses a similiar set up.
Does the sound increase with engine rpm?

Wilsophia

fuel pluge valve ??

BradBodsworth

hi guys, thanks for your replies, the sound started off quiet and has been getting progressively louder and louder the more I drive it. Interesting about it is that it only does it when the engine is warm.

It has a rhythmic ritt ritt to it, and as I increase rpm it gets faster. On the open road you cant hear it at all, although this is possibly because its doing it so fast you cant hear it. I did take the serpentine belt off and stil it made the noise, so not supercharger.

So it must be from the block. Couple of questions I have....

- How would I know if its the chain tensioner just by visual inspection?
- Is it a massive mission to get all the way to the timing chain? I am technically minded but not a fundi at this.
- How would I know if the chain has stretched?
- Obviously I will look at the guide rails etc, but are there any other giveaway signs that the rails are game over?
- If I open up the block and the chain has too much play in it, does that mean chain stretched or chain tensioner more than likely game over?


Your opinions are proving very valuable....

Velociabstract

Dang, no one knows? I don't know the M112 that well, my M112 engine has only 18000 miles. On the M110 my timing was bouncing around so I bought a new tensioner and timing chain. When I cut a link and started threading the new chain on, part of a long guide rail broke off and fell. No prior symptoms. The tensioner does just that. Takes up the slack so .... the chain should be tight even with some stretch. I don't think it's the timing chain or tensioner. Again, I wish someone with more knowledge than I have would SPEAK UP! Geez.

Les