I bought my 2005 MCS R53 back last May with 115,000 miles. Everything's been great, previous owner took good care of it and had it serviced when it needed to be. I've been really happy with it.

Once winter hit and it started getting cold, I would hear a groan coming from the passenger side of the engine. I say this because it seems like it's "over there" (waves toward passenger side). I really don't know where it's coming from. It wouldn't happen every day, maybe every couple of days for 10 days. Then it stopped. Now it's back after a two-month hiatus. I've done lots of reading here that the supercharger will sound like it's eating a bucket of bolts when it goes bad. Mine doesn't sound like that, it's truly more of a groan. Also, it disappears within the first mile of driving (if it even happens at all). I've opened the hood up to try to locate the source of the sound, but no way, I can't really tell. The noise doesn't really sound like the normal PS pump failure I've had on other cars. It doesn't really change when I turn.

I'm thinking about taking a quick video then next time it happens in order to further illustrate what's going on, but like I said, it's hard to tell what I'm hearing. What's your gut instinct on this?

 

Maybe the cold weather is just giving the pump more work before it can warm up.
It sounds to me like you shouldnt worry about it unless it gets worse, or if it starts making more noise when you turn the wheel. Check your fluid level just to make sure it's filled.

 

Genius. Don't know why I can't think of these things.

Update: Made the same noise after work, but went away after 10 seconds. I'll check the fluid in the daylight tomorrow.

 

I made a follow-up video of the noise. Keep in mind it sounds way more metallic on the recording than it does in real life (harsher, more grinding-like). It sounds like much more of a groan in person. It also stopped within 20 seconds total, just fading away over the course of a few seconds.

 

does not sound like a power steering pump to me

 

check your belt tensioner and your crank pulley

 

After further time spent listening to this, I agree. The noise was separate from me turning the wheel back and forth to test that theory.

Crank pulley on the....supercharger? I'm assuming the tensioner is a spring loaded pre-set tension.

 

I would agree open the HOOD and make a video of the tensioner - is it jumping around? Which would mean your tensioner is failing? Other thought is the timing chain tensioner - rattle.

I know you said the video is much more metallic than real life but it sounds very rattly and less groaning. There is also an idler pulley to explore.

 

I wish I could hear another MCS running side by side so I could compare. It's hard to diagnose with limited experience.

 

where are you located?

 

Southwest Oregon.

 

open the bonnet and record again....hit the gas. Is it rotational and changes sound when revving engine ? Could be the belt tensioner. They typically last no more than 125K. I replaced mine with an aftermarket one.

While less expensive, the inner strap which runs through the spring is made of a thinner / cheaper metal and due to its composite, at idle it vibrates/rattles louder than the OEM one did.

 

Work is really interfering with getting this checked out. I can't get home in the daylight to take a look, but I'll have a chance to do so tomorrow. If it is the tensioner, does the whole unit get replaced, or just the pulley? A quick look showed it to be around $100 or so for the whole unit.

 

The tensioner is sold as one whole unit...I don't think you can buy just the "Spinny" part = pulley.

If it's the idler pulley which is below the tensioner those are easily found online for $40....the bearings on them can fail

 

You actually can replace just the spinney part (aka pulley), but you're better off replacing the whole unit, because the dampener also fails. The idler, as you said, is cheap and easy to relpace. First off, check that the noise is from your belt train. If you have the tool, remove the belt and start the car. If the noise is gone, there's your problem. If you are very careful, you can use a pry-bar as a stethoscope and place the end of it on non-moving parts in the belt train with your ear on the other end (the handle end) to determine if the bearings are shot.

 

Thanks Helix -- I didn't know the pulley was sold separately. I am highlighting very careful as I feel like the OP's use of "spinny" part might indicate a general lack of knowledge of the operations of the car. If you put anything near the fast moving belt and it catches - it will be flung across the room or through whatever is in front if it. If your clothes, fingers, tie, dreadlocks etc.. get caught in that belt I DO NOT want to read about it in the news. BE SUPER CAREFUL

-- I would suggest you take a video with the hood open and post it back so we can better help you assess.

What is your comfort level / mechanical ability??? The pulley takes a bit of work and as Helix mentioned removing the belt requires a special tool (or some ingenuity) which sells for between $60-80. I have one because I change my own belts and it makes the job a ton easier.

 

A long screw driver also works well as a Stethoscope.
If you have a Harbor Freight nearby go buy this mechanics stethoscope:
http://www.harborfreight.com/mechani...ope-69913.html

 

Haha, point well taken. It's early here, and my sinuses are filling up wanting to make my head explode. I'd say I'm an advanced DIYer, please forgive the "spinning part" comment (I did say "spinning" originally, not "spinny"...much more technical sounding). I do have a mechanic stethoscope, I'll poke that around and see what I hear.

 

In the year ive owned my r53 ive had all three of those problems.

The sc made a crunching noise that never went away like that.

The power steering pump sounds terribe too but it's very obvious because the noise changes when you turn the wheel.

Im going to go with everyone else and guess it's the tensioner pulley. Really hard to tell with the hood closed, but sounds similar to what I was hearing when mine went. I haven't had my crank pulley die yet (Im knocking on wood) so cant comment on that

 

Well, wouldn't you know it, yesterday there was heavy machinery out front making a lot of noise digging the street up, so no chance for getting good audio. Once they left, I started it up....NO SOUND. Same today, no sound. Ugh.

So I popped the hood to see what my little eyes might see, started it up and started looking. The tensioner pulley does bounce ever so slightly, and it's got a nice coating of grease right around the center of the pulley. I'm hoping that's the source of the trouble. I'm just not sure if the bounce is due to just general engine vibration, or a worn bearing.

While in the middle of doing that, the engine starts tapping, so I quickly took some video, which you can view here:


That sounds like an unrelated fuel injector noise. It made the noise for about 30 seconds, then went away, then came back again. I put a stethoscope near injector number 1 and it sounded like it was coming from there.

 

I can't see the tensioner very well from your video but that sound - sounds more like this :