Porsche Enthusiasts Club Forum

Not sure if it's relevant, but I remember reading there was some error in the translation of the original German instructions. Maybe that's where turning the engine backwards originates from.

Just wondered if you ever contacted Bruce at Arnnworx and what he had to say about it.

turns out my 90 degree method was a bit loose...so to speak...as in not correct and not 90 degrees, more like 75 degrees...with my left forefinger and thumb I turned the belt down wards but couldn't get it past 75 degrees at maximum strength...I have now slacked off the auto tensioner a hair and can turn it 90 degrees with forefinger and thumb. The water pump pulley can now move with a bit of force from one grippy hand.

Of course on the Arnnworx tool it says I am super sloppy, loosey goosey.....

I have also asked Bruce at Arnnworx what the issue could be.....turns out from my extensive research on this issue I am not alone....

I'll sleep on that now...happy dreams all!

Back on it..
So, I took the separation bar off and TB Idler pulley. Got my tool and plugged in the tension...then on to the90 degree twist method. Grabbed hold of the belt about half way across the separation bar, if it was there, and could turn is to 90 degrees with thumb and forefinger. This seems about right. Picture below...in action.....
So finger and thumb is right and tension tool is right...it's just the water pump pulley will not move with one grippy hand......
Just trying to find someone with an auto tensioner who has done similar...
Thanks,

M

Seems to me you're trying to combine 3 different methods of tensioning the belt. 90 degree twist is fine if you've changed a lot of belts, and your fingers are calibrated accordingly. Tools if really understand how to use them. Water pump, depends how strong your hand is. Pick one, and go on you tube for a guide.

Thanks. There’s only one correct tension surely Suppose it doesn’t matter which method you use. Just asking with an auto tensioner with belt tensioned correctly can you turn it by hand? Thanks
M

I couldn't on mine.

Than you. That’s the info I’m after. Cheers. Michael

Yup fit the new belt, standard tension up & turn at least 2 turns CW to check the marks still line up. Then back, if the manual says 1.5T then I won't argue but there have been loads of TSBs on this area!
Release tensioner & retighten. Turn a few revs to check everything OK. I seem to remember with the Krikit that the new setting was a fraction tighter than 90 Deg on the longest run.

Thanks for this.

So the big question...after you have tensioned the belt correctly can you turn the water pump pulley by hand?!

Thank you.

Michael

We're going around in circles. Turning the water pump by hand ISN'T part of the standard tensioning procedure. The belt will be looser than Porsche specify. It probably isn't suitable for you.

OK, I'll stand down. Thanks Pauly.

Had another play (final?) with the tool and it seems to work and comes in within spec. I did this about 20 times.

For mine the auto tensioner once slacked and released needed a little nudge with the pin wrench to tighten it up. i.e it wouldn't tension it automatically when you released the slack..which I guess is fair enough for a piece of equipment over 32 years old.

Balance belts tomorrow.......should be a breeze

M

Well, had final, final play this morning.....just can't take up too much brain space on this.....

So, I was looking at the printed instructions and on the back I had written down the specs of the belts when I had a play two years ago. I did not change the belts then, this was done by a Porsche Centre in March 2016...it has been documented as such and even have a nice printed certificate!. So hopefully done properly. I noted back then that the water pump pulley could just be moved by hand. Also, having not got to grips with the Arnnworx tool instructions then, like I have now I thought it was in spec but had not moved the slack to the top. So in effect it was slightly slack. I have driven her 5000 miles in the two years and it was driven a few 1000 more before me when the belts were changed in March 2016.

SO, whilst the Arnnworx works well for the balance belt I think, as Jim has stated before, that it is just too tight for the timing belt with the Auto tensioner. I have contacted Bruce at Arnnworx and he said he has never tried the water pump method. With the Arnnworx at the tension spec the Idler pulley is really 'on' the belt and you can't really spin it with a finger owing to the friction from the Timing Belt. It just feels too tight. So I have tensioned the belts as per my notes before. It has been good with this method for 5000 miles with me in the two years so hopefully it should do the same again. Obviously I'll keep an eye on it and retention after 1000 miles or so.

I guess that a timing belt that is a little loose is better than one that is too tight. Further to this, this is done on a cold block so imagine as the engine warms and expands a little the belts will naturally get a little tighter as well.

Balance belt was done this morning in 15 mins...........

Thanks for you help.

M

Everyone over does the balance first time, sings like a stuck cat, whines like my mother in law

So started her up this morning with all the new belts and water pump on after a 4 week lay up.
Turned key....all lights on the dash as normal, started her up...and....off she went! I'm on ramps..so not properly off but you know what I mean. Belts were definetely whinny for the first minute. Not sure which one...been a while since I have had all that wonderful noise in my eardrums!
Then after two mins all reverted back to normal...as in how it was before..infact it did seem a bit quieter on the belt front...but haven't actually driven it yet.

No obvious coolant leaks though...which is a relief.

The lower balance belt is out of time though. It has gone from 7 o'clock position before I started it to around 10 o'clock. I have brought it up to TDC more than 5 times this morning and it remains in the same place. In between starting her up a further three more times. So I guess the balance belt is a bit loose. I can cope with that....and tweak it later.

Looking at the power steering pulley arrangement there is a fair bit of vibration and 'wobble' on this bit. My little power steering strut broke but I have it fixed by our local welding bod. I can't see how else you can hold the power steering pump bit still . There is still a fair bit of vibration down there. It would be nice if I could somehow hold it in place. I can see my fixed strut having a torrid time with all this vibration.

So, a little breather now...before I tackle the front breaks....

Thanks.

Do not run it without the balance shaft correctly timed. The vibration can break the oil pickup. The balance is fiddly because it keeps spinning as you put the belt on but it needs to be right.