Top tip for tensioning balance belt
I did the cam belt and tensioner a few months ago but was never happy with a kind of whining noise coming from the belts area. Some people told me these engines had a tendency to whine after a new belt so I left it for a while to see if it died down. But it didn't. At first I thought it might have been the auxiliary belt, but when I removed it, there was still a definite whine. So off with the covers and the balance belt - sure enough, the whine was gone.
I took some care in refitting the balance belt, lining up the white marks on the belt with the marks on the pulleys etc (though I can't for the life of me think why that might be useful unless for some timing light action). Also, and this is probably where I went wrong last time, I was precise in getting the two balance pulleys lined up properly. I don't remember taking all that much care when I originally put the balance belt on, so I guessed this was my issue.
Sure enough, the engine is now running like a clock, whine gone. It seems that if the balance shafts are not exactly where they need to be when No 1 piston is at TDC the engine doesn't like it.
Anyhow, the top tip. I was really struggling to properly tension the balance belt tensioner pulley. I've got the right tools etc, it's just that you need to be an acrobat to hold the tool on, rotate it, check the dot on the tensioner is exactly in the middle of its travel and then tighten the 10mm nut behind. After an hour I was chucking spanners around the drive.
The solution is to support the engine on a jack, and remove the major obstruction, which is the drivers side engine mount. Three RIBE bolts and a 19mm bolt into the wing mount and off it came. After that it took literally three minutes to tension the balance belt properly. The mount isn't difficult to remove or replace and it makes the whole job so much easier.
Anyway, thought I'd mention it in case it helps someone.