Hi Guys,

Im after a bit of help. Had the mini for a while now and have nearly always noticed a knocking noise from the supercharger, but its getting worse.

I normally notice it when started from cold or when revving from 2000rpm upwards. There seems to be a lack of power and a lack of boost, iv never been in another R53 S so wouldnt now how much boost to expect (If you get me :S). Apparently it could be the boots or the air bypass valve??

Any help would be much appriciated.

Matthew :)

hi ya

It could be a few things making the knocking.
if i was you i would remove the SC belt and make shore the idler pulley is ok the bearings fail in them.
while the belt is off rotate the SC pulley see if it feels smooth it should not be tight to turn but you will have a little resistance there. rock the pulley back and forward and see if you can feel any slack this will tell you if your coupler is ok.
grab the pulley and try to move it in or out and up and down this will tell you if the bearings are ok or give you a rough idea.
also while you have the belt off it worth putting a new one on if its not been changed for a while.
unless you have a gauge to tell you your boost pressure its very hard to tell if you have a leak or not and what the condition of the SC rotors are in, it is always worth checking the intercooler boots are ok.
the by pass valve when it goes wrong you will know it will cause all kinds of problems.
but on the early MCS if its not been changed its always worth popping it out and checking it and doing the bypass valve mod to it if it need it

what makes you think its down on power?

hope this helps

Hi marque. Thanks for your help, iv been told it could be bearings but it is more than likely the bypass valve, my mates was only running at 140bhp he had the bypass valve changed and put it up to 161bhp... Regarding the boost and power loss It just doesn't feel like a 160-170bhp (also got a pipercross filter and jcw exhaust) car to drive and it doesn't feel like there's no go in it, As where other turbo and supercharged cars iv drove shove you back in the seat this doesn't seem too.. Cheers :)

Also where could I get a bypass valve from? I may change it anyway, how much are they roughly?? Iv also been told that taking the negative terminal off the battery resets the ECU and gives u a power gain?? Cheers

Also where could I get a bypass valve from? I may change it anyway, how much are they roughly?? Iv also been told that taking the negative terminal off the battery resets the ECU and gives u a power gain?? Cheers

Hi ya

If the by pass valve is not shutting if you remove it you can adjust it it's pritty easy to do

http://www.mini2.com/forum/first-generation-mini-tuning/145970-bypass-valve-modification.html

bypass valve around the £65 ish from bmw or same from lohan
lohen.co.uk - Track & Fast Road Performance for your New Mini - Online Shop (http://www.lohen.co.uk/shop/proddetail.php?prod=MINIBypassValveG1&cat=5)

Some guys do them with a better spring
Detroit Tuned Bypass Valve MINI Coooper Bypass Valve (http://www.outmotoring.com/mini-cooper/detroit_tuned_mini_cooper_bypass_valve.html)

Resetting the DME just starts it learning again no real power gains it's self adapting that's why it's nice to give them abit of a hard time now and again.
If your going to reset the DME remove the neg terminal and leave it for at least half hour.
After you do any engine mods it best to do this anyway

Hope this helps

Ahh thanks for the help and advice :).

Im going to have a go at fixing the bypass valve tonight. Is there any way where i could have someone rev the car and have a look at the valve to see if the valve is shutting? Also where exactly is the valve located?

Cheers

Hi ya

There is no way to see if the valve is closing ok unless you remove it and check it.
It took me about 10 min to get it spot on when I adjusted mine, take your time it's worth it my one was open by about 1 mm some are worse than others and some are ok luck of the draw I suppose
It will take you an hour or two to do if it all comes apart easy

As you look at the engine it is under the right hand SC horn. to get to it you need to remove the
intercooler and the cover
air intake pipe from the airbox to throtal body
Air box intake pipe from radiator housing cover to airbox
I removed my throtal body and cleaned it while I was there
Then remove the lower hose clip on the hose adaptor between the bypass vavle and SC intack duct use a small screw driver and the clip will pop open
Remove right hand SC horn buy push down in the SC intack duct but not to hard or you will break it. Pull the SC horn off it will be abit of a struggle but will pop off you may need some wd40 on the hose to make it easer to come off
Then on the bottom of the SC horn is your bypass valve
Just remember any pipes you have to disconnect go back on properly and cover up any holes so nothing falls in somewhere where it should not be

Thanks very much. Iv printed your instructions and diagrams off the links you gave me. Hopefully will be doing it tonight in the garage. My brothers a mechanic so hel be helping me anyway.

Il keep you posted on how im doing :)

Got to the bypass valve to find it fully closed! What else do you think it could be? If its the bearings how much would it cost to replace them? I spoke to a mini dealer and they said that if it's not bypass valve there's no other replaceable parts to buy and I would bee a new charger! I really don't want to go down that route, cheers

hi ya

To strip an rebuild the SC is an easy job but you have to be very carefull and have the right tools,
I would not recomend doing it if your not 100% it can be messed up very easy
If you keep an eye on eBay you want a generation 5 SC they have black rotors there the later type the jcw and standard one are basically the same apart from the pulley size you will pay around 300 to 400 for a good one with delivery millage

If you look on eBay at eaton m45 supercharger rebuild kits it sounds lie the coupler has worn but you will only feel his when the belt is off

I would remove you SC belt and check it and also check all you tensioner pulleys to