37 replies to this topic

[Stevie W]

Just a thought!

You've fitted a supercharger which means a different crank pully to run the 'charger.

If you've got an excess crank end-float problem, is the crank pully hitting the rad bracket? Although from the video the noise does sound muffled like its coming from inside the engine itself.

As above a couple of stout screwdrivers behind the pulley will soon tell you if your thrust washers are excessively worn. To me, it sound like the crank web on the thrust side of the centre main bearing is touching the block when you disengage the clutch.

Hope this helps! Steve

Edited by Stevie W, 09 October 2012 - 11:03 AM.

[Nick Warwick]

Yes i have the different crank pulley fitted to run the charger.

I will check to see if the pulley is hitting the rad bracket just to make sure.

Just push the screw drivers behind the pulley?

cheers

[Stevie W]

Yes that's the idea!
Because he crank is heavy and runs in close tolerance bearings, its not going to slide easily, so a couple of screwdrivers behind the crank pulley just to lever the pulley forward will tell you if there's any endfloat. Anything visible, no matter how small means something is drastically wrong with the thrust bearings!
Cheers, Steve.

[Nick Warwick]

Right i had to move the mini out the garage at the weekend so fired it up, the knocking seems to happen without the clutch being pressed now (maybe this time only) slightly revved up he engine and it sounded awful until the revs went past maybe 2000-3000rpm sounded normal then.

[Stevie W]

Hi,

Sounds like the problem is getting gradually worse!
Try not to rev the engine too much with this noise going on, just in case something inside the engine is hitting something else.
I am assuming you have no oil pressure problems and its not the big ends knocking?

Unfortunately, I think its time to start stripping the engine ancilleries down (clutch and crank pully end) and looking to see if any rotating parts are touching any fixed parts. Any components that have been touching will be obvious my gouges in metal.

Once you've eliminated all of these, its time to start stripping down the engine itself to find out whats really going on. Hopefully you'll find something external to the engine that accounts for the noise, but as I mentioned earlier in this post, from the video at least, the sound seems "muffled" as though its coming from inside the engine block.
Good luck with your search!!!!

Best wishes, Steve

[Nick Warwick]

Oil pressure seems fine the light goes off after start up.

I will begin the strip down over the christmas hols while i am off work. Think i will just roll the engine out on the subframe this time.

Thanks for the help

[Nick Warwick]

Watched a wheeler dealers over the weekend, Merc SLK with a supercharger fitted. It was giving off a similar noise and ended up being the bearings in the supercharger being shot.
Could this be the problem do you think? because like i said earlier if i let the car idle it bangs and if revved it stops.

Just a idea i thought i should share because people said it sounded like a release bearing.

[Nick Warwick]

Took a better video before i just stripped the SC off the engine. The noise sounds like it is coming from the nose end of the supercharger.

Edited by Nick Warwick, 10 December 2012 - 03:45 PM.