'02 MCS Engine sound w/ video and sound!
 

Just started today. Makes the sound with the clutch in and out. When I rev and let off it makes a gear kind of noise. Is it the chain tensioner or possibly the S/C pulley? It is definitely from the passenger side. 56k miles.

video




Its the same exact video, no need to watch both

Any overheating? If so it's the supercharger/water pump gears. It sounds like either the supercharger timing chain tensioner or possibly even the crank pulley. 1st thing i would check is the crank pulley since it's an easy visual check. Just look at it and see if there is any separation or cracks in the rubber. If it's not that then use a stethoscope or stick check the timing tensioner and supercharger. If it's the charger you'll need a new one or a rebuild on your current one. If it's the tensioner just swap it for a new one.

All 3 of those are pretty common problems.

Supercharger rattle.

Tensioner rattle

Crank pulley rattle

Sounds more like the second one. Also forgot to mention that it sounds like it coming from the upper rear area.

Thanks for quick replies guys.

I was thinking the same. Easy fix and the cheapest of the 3!

No overheating

Whilst driving:
- frequency increases when I lift throttle
- frequency also is mostly proprotional to engine speed

My initial thought was chain rattle. Sounds almost identical to an Audi after an oil change. Takes a lot of Audi's a few seconds of chain slap after an oil change before the tensioner pressurizes again.

Definitely want to get that fixed ASAP.

Read here about the dangers of continued use and even changing the tensioner but driving merely 25 more miles to get an oil change afterward:
https://www.northamericanmotoring.co...e-problem.html

Unlucky owner had chain rattle, put in new tensioner and was driving it fixed to go get an oil filter and motor lost oil pressure on the drive.. Only 25 mile drive too! The longer you drive with that sound the more damage will occur to the chain rails which are plastic. That plastic will break apart and drop down to the oil in the oil pan. Sooner or later the pieces will get sucked up into the oil pump and clog the mesh filter screen on the oil pump, starving the engine of oil.


May be worth further diagnosis with a stethoscope like Clay mentioned.. If you don't have a stethoscope, putting your ear up to the handle end of a long screwdriver that where the flat blade is pressed against various components listening for the loudest and most clarity point. Check the supercharger, timing case cover, valve cover, etc until you feel confident about the pinpoint of the noise to determine if it is indeed the chain tensioner.

Also, if you or anyone else ever wants an easy way to rule out the supercharger, remove the serpentine belt and start up the engine. If the noise is still there then it is NOT your supercharger as it only spins when the belt is turning.

Also, harmonic damper/crank pulley whatever you want to call it will rattle if the rubber cracks/breaks. You may notice excessive wobble of the balancer with the engine running. By removing the belt you can grab the balancer (engine OFF obviously) and see if you can wiggle it for play indicating broken rubber.

Not the chain tensioner. Ball sacks.

Oh yeah. When I lift the throttle the sound frequency increases then slows down.

Not sure if they make noise when they go out maybe someone can give more insight, but, i wonder if the timing chain guides have gone out? Could even be a bad idler pulley.

Have you ruled out the supercharger (diagnose idle with same method by removing the belt) and crank pulley/harmonic balancer using erik's method?

Edit: idler pulleys seem to have more of a whirling noise instead of ckicking when they go out. If you have a harbor freight near by i would invest $4 into an auto stethoscope and start listening to every moving part in the engine bay.

Rod knock probably. Pull the belt and fire it up just to see if it's any accessory.

Jeremy

Not a rod knock. I know that sound. Its almost a gear or chain lash sound. I ruled out the S/C. Both sides are full of clean oil.

Is there anyway easier way to remove the belt then disassembling half the car?

Remove belly pan, untension tensioner and pull belt off supercharger pulley then remove from below.

Jeremy

Easy way to remove tension from tensioner? I don't have access to the tool.

Here's how I used to do it before making a tool/having OEM tool.

https://www.northamericanmotoring.co...belt-swap.html

Jeremy

that sounds exactly what I've been going through... it was the supercharger.. Had to have it rebuilt.

Nope. The s/c was fine. It turned out I bought a car that was in an accident and ran wothout oil. So my problem was metal particles in the engine.

Good lord. How did you come to this conclusion?

Is it still running and if so have you dropped the pan and cleaned off the oil pump inlet screen?

It started to lose power bad so I sent it to Detroit Tuned. They initially thought it was an exhaust valve until they pulled the filter and found it full of metal