1st Gen R53 Cooper S Timing chain cover gasket leak causing belt squeal?

Discussion in '1st Generation: 2002–06 R50, R53 & 2004–08 R52' started by Dennis Bratland, Jan 18, 2017.

  1. Dennis Bratland

    Dennis Bratland New Member

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    Would a timing chain cover gasket leak cause oil to seep around the idler pulley, onto the belt, and cause a squeak?

    I've been trying to isolate this cold-engine squeal ever since I put on a 15% pulley on my 2005 MCS. It had about 25k miles when I put it on; I've driven 500 or so since then.

    I put in a new AC Delco 38404 tensioner with the pulley, and a Gates K060535 1379 mm belt, so that shouldn't be the source of the problem.

    I've been poking around with a mechanic's stethoscope, spraying water on he belt, and so on. The new belt I put on with the pulley looked glazed after only a few hundred miles, which is evidence of slipping I believe.

    I ran the engine briefly with the belt removed, and the sound disappeared. I put on a new belt, and the sound was much worse, but after a few minutes it went away. Then after driving a bit, it was back the same as before: squealing when cold, quieter when warmed up, but still noticeable inside the car above 2500 rpm.

    I removed the idler pulley to see if it was turning normally, and it seemed fine. Spun about as smoothly as the tensioner pulley does. But when I removed the pulley, I saw engine oil oozing out from the bolt hole. It was a droplet of about 1/4 teaspoon that flowed out when I removed the bolt. On the diagrams, there son'r appear to be any openings to the interior of the engine through that hole, but it does pass through the timing chain cover and the gasket appears, from the drawings, to be right next to that bolt hole.

    So is that the cause? Gasket starts to fail, oil comes up and around the bolt, drips past the spacer, and then runs down the sides of the pulley, causing the belt to slip?
     
  2. MCS02

    MCS02 Moderator
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    It sounds possible. I change my idler pulley when I change my tensioner. On occasion the timing chain cover gasket does leak and has to be replaced. You could put some plumbers tape on the threads of the idler pulley bolt to keep oil from coming out. Then get some belt dressing and spray on the belt. I think they still sale it. If there is no oil on the belt and you spray belt dressing on it, it will not slip. If too much oil has gotten on the belt you will have to replace it.
    Is there any play in the idler pulley bearings that could cause some slack?
     
  3. Crashton

    Crashton Club Coordinator

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    Change your idler pulley & DON'T use belt dressing on anything ever.
     
  4. Dave.0

    Dave.0 Helix & RMW Powered
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  5. Dave.0

    Dave.0 Helix & RMW Powered
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    WTF Lee Belt Dressing??? :lol::lol::lol::lol::lol:

    [​IMG]
     
  6. Metalman

    Metalman Well-Known Member
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    BELT DRESSING...... Oh the Horror of it all....

    The only acceptable dressing is the kind you stuff up a turkey's butt....

    turkey.JPG
     
  7. MCS02

    MCS02 Moderator
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    Oh good grief! I didn't say dump the hole can on it, just a little to see if it stops making noise! I do agree with crashton I would get a new idler pulley.

    Belt dressing it's almost as good as JB wield and duct tape.:D
     
  8. Dennis Bratland

    Dennis Bratland New Member

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    Forgot to mention I put on an ATI 0% crank pulley at the same time I did the SC pulley and the tensioner. You do this stuff all at once so you don't have to take the car apart three times, but if anything goes wrong it's hard to guess which thing you messed up.

    I wasn't specific, but the reason I was spraying water on the belt was following the troubleshooting steps here:
    http://blog.bavauto.com/14664/bmw-and-mini-belt-or-pulley-squeal-or-squeak-how-to-diagnose/

    When I sprayed water at first, it made the squeal quieter, briefly. After I replaced the glazed belt, spraying water made it squeal much louder for about 10 seconds then it went back the way it was. I think the water spritzes maybe serve the same troubleshooting purpose as the belt dressing. But in my case, the result is inconclusive.

    I'm about to replace the idler pulley. When I do I'll see about that oil leak again.
     
  9. Dennis Bratland

    Dennis Bratland New Member

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    So I replaced the idler pulley, and added some RTV around the spacer and the bolt, though I don't think it was necessary. There isn't any oil on the belt or pulleys. But it's still squealing the same.

    At this point I'm kind of stumped. Next I could try putting the old tensioner back on, or removing and reinstalling the supercharger pulley. Maybe it's misaligned, or not fully seated? Seems unlikely. Similarly, the crank pulley could be off a bit, in some undetectable way. Could be I have to look into the supercharger snout. Rebuilding that isn't terribly difficult.

    (I just got a set of 380cc injectors, so I could dig into the supercharger while I'm installing those. Next I want to get a JCW ECU flash at the dealer, but I don't want to take it to them with any weird problems like this belt squeal.)
     
  10. Dennis Bratland

    Dennis Bratland New Member

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    My supercharger pulley is misaligned.

    It's about 1/8 inch out from the rest of the pullies. I probably could have seen the 1/8" of the belt overlapping out from the edge of the idler pulley, looking down from the top, but until now it looked normal to me. Cravenspeed says to check that the pulley is fully seated by looking through the inspection hole in the center and see if it's touching the end of the shaft. Which it is.

    The problem is, the whole shaft is pulled out of the snout. I ran into this when I was removing the old pulley. The shaft moved out, and I tapped it back into place. It looks like it's not going to stay. I used a brass punch to tap the pulley and shaft back into a seated position. I expect the squeaking to start up again soon when it works its way loose. I think I'm going to have to remove the supercharger and rebuild the snout. Most likely the bearings are not fully pressed into their seats. I've found walkthroughs on this, and a video on the M90 snout, which is like the M45, but longer. But I haven't seen a cross section or diagram of the exact position of the parts inside the supercharger drive snout, so I'm only guessing.
     
  11. MCS02

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  12. MCS02

    MCS02 Moderator
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    How about taking some pictures as you take the SC apart. I would like to see a how to incase it works. Just remember when you put the belt back on use lots of BELT DRESSING!:biggrin5:
     
  13. Dennis Bratland

    Dennis Bratland New Member

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    The process seems to be this:

    http://www.3800supercharger.net/nosedrive.html

    or this

    [ame="https://www.youtube.com/watch?v=m7lYCuj4w2Q"]Eaton M90 Supercharger Snout Rebuild: Part 1 - YouTube[/ame]

    Because these sites are generally saying the layout of the M45 is the same as the M90 above. I still wish I had an Eaton manual, or at least a clear exploded view or parts breakdown.

    The free play and rattle sound he describes here in the Pontiac/M45 video matches what I'm getting:

    https://youtu.be/SGpA86fToGs?t=9s

    With the belt squeal eliminated, it's quiet and sounds normal, except there is an intermittent rattle or knocking, like, as he says above, a rod knocking or a loose valve lifter. The design of the Mini's coupler is slightly different than the Pontiac he has here, but when I get it apart I expect to see the enlarged openings around the coupler pins shown here https://youtu.be/SGpA86fToGs?t=1m27s

    I have the bearings and seals and an uprated coupler for my supercharger nose, but I need to put my arbor press back together with some new parts before I can start.
     
  14. MCS02

    MCS02 Moderator
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    Here is a video of what it sounds like if the oil has leaked out of the SC. Is this what you are hearing?

    [ame="https://www.youtube.com/watch?v=AtqX2MSgF6A"]BMW Mini Cooper S R53 Eaton M45 Supercharger Noise - YouTube[/ame]

    This one shows what happens to the PTO if the oil leaks out.

    [ame="https://www.youtube.com/watch?v=97-7VTZLpv4"]GTT MINI R53 Cooper S Supercharger Diognostic / rebuild service - YouTube[/ame]
     
  15. Dennis Bratland

    Dennis Bratland New Member

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    I listened to a few videos like that, of the typical supercharger with the typical gear drive failure, and it doesn't sound like any of them. I used a mechanic's stethoscope too, and don't hear any distinct grinding or rattling inside the drive or PTO gears similar to what you usually have with these.

    I could be misinterpreting the sounds, but to me, it is best described as a rod knocking. Or on a traditional engine with exposed spark plugs, when a plug wire is loose and you can hear the sound of the spark jumping the gap from the wire to the top of the plug. I actually checked the plug wires the first time I heard it, because it sounds so much like that.

    Audio is a weird thing though. Just compare reality with any exhaust note video on YouTube. It's a black art to record sound realistically, and even if you do, what you play it back on makes all the difference.
     
  16. MCS02

    MCS02 Moderator
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    Ok I did not think this was the problem but thought I would check.
     
  17. Dennis Bratland

    Dennis Bratland New Member

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    All right: I got my supercharger out and I disassembled the nose. My guess that the bearings were unseated was correct. Both the inner and outer bearings were about 1/8" away from their seats. I had at least 90 ml of clean-ish looking oil in there. So at least it wasn't leaking. And the gears look healthy.

    I tried to make videos, like all my YouTube heroes do, but I rarely shoot video, and the focus turned out to be hopelessly off. I need a head mounted camera that is made to focus at close range.

    The good news is it isn't really necessary for me to make any video at all. The sources I read that said the Eaton M45 is the same as the M90 were correct. So you can follow the same video I did for the longer-shaft M90, from someone who really knows what they're doing..

    To get the super charger out, use ModMini's SC oil change video:

    [ame="https://www.youtube.com/watch?v=FA9QIXtBGuM"]MINI Cooper S Supercharger Removal & Oil Service R53 Eaton M45 - YouTube[/ame]

    Then follow GR8racingfool's excellent video: Eaton M90 Supercharger Snout Rebuild: Part 1. He has experience with these, and has several good tips and heads up warnings to heed. You'll need an arbor press, and a selection of 1/2" drive deep well sockets, or other similar shaped seal-drivers and supports, as you'll see in the videos.

    [ame="https://www.youtube.com/watch?v=m7lYCuj4w2Q"]Eaton M90 Supercharger Snout Rebuild: Part 1 - YouTube[/ame]

    The reassembly is in part 2:

    [ame="https://www.youtube.com/watch?v=I1H47_d4JTI"]Eaton M90 Supercharger Snout Rebuild: Part 2 - YouTube[/ame]

    (Apparently on cars that are not Minis, the supercharger is not buried in a dark crevasse of the engine bay. It's right there, where you can see it; see it all, shamelessly bare naked in front of the whole world. So some guys figure why not polish it? Shiny and chrome, ride eternal, etc. I guess it's a not-a-Mini thing.)

    The M90's longer shaft means that the pipe section he uses to remove the inner bearings doesn't need to be so long, but it is necessary. I had a universal joint half that served the same purpose, but you should plan on having a 4" to 6" section of steel pipe to hold the shaft, or plan on shopping for the right size pipe after you take it apart. The bearing and seal kit I got was from one of the many eBay vendors that offer M45 kits. I looked an eBay vendor that had had several recent positive feedbacks from buyers of a supercharger kit. I haven't installed it or driven it yet, so I can't say if those are the best parts or not. But I don't know where you find OEM part numbers for Eaton M45 internals. If you're in doubt, speak to an aftermarket Eaton parts vendor.

    I'm not going to do anything with the back half of my supercharger except change the oil. I have to stop for today but maybe I'll have time to reassemble everything on Saturday.
     
  18. Dennis Bratland

    Dennis Bratland New Member

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    Well, that's done. All good now.

    I got sidetracked with a couple things, putting in new 380 cc fuel injectors and replacing the thermostat. The belt looks good, sounds good. It is lined up on the pulleys, and not making any squeal. Car seems to drive just fine.

    Now I can get into the dealer and flash the ECU with the JCW map, to go with the JCW intake, injectors, and Milltek exhaust. Also want to get my new rear fog light enabled and turn off that horrible windows-and-sunroof opening by accident "feature".
     

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