Stuart Waite

Hi Namasgt
I have dropped the oil and checked the magnetic sump plug and the filter - all perfectly normal even under a microscope. As previously posted the oil was changed when I replaced the water pump.
Cheers anyway
Stuart

the flyin' scotsman

Couple of questions:

what timing belt did you use?
who manufactured the water pump? new/rebuilt?
what method did you use to tention the belt?

Bill Ball

This may not be the cause of the thump, but there shouldn't be any play. The shaft and arm fit to the bushings should be firm and snug. The belt fuzz is evidence that things are going out of alignment probably due to this. Glad you chose to replace them.

These lower idler rollers are more trouble than they are worth. They easily could be the source of the noise. The belt should rarely contact them, but the loose carrier fit on the pin may allow this part to move with engine vibrations. To replace it costs a pile, so I would try to shim the loose side somehow. Does the noise locate to that area? I've seen noises in this area that quieted when I steadied the roller.

oz928s4

Let me know what you need I have all the old stuff after updating to the Porken system.
Postage from Australia and it yours.

the flyin' scotsman

Another point re. the lower idlers............they're not required with the Porkensioner.

I took them off and one was seized solid. They're in a better place now.

Landseer

Mine, too, on an S.

What's the endplay measurements, BTW?

Stuart Waite

Hi Malcom
In answer to your questions, the belt is Continental, the pump is a new Laso and the tensioning was done by me, intially by feel then adjusted with the engine running by backing off the adjuster until the warning sensor kicked in then re-tighting until the warning was cancelled. After initial bedding in this was checked professionally by my local shop and was found to be spot-on!

Lizard928

Stuart,

The belt warning light triggers at 4.0 as per the Porsche tool. It should be set to 5.2 though.

So if you did it that way you got really luck.

Stuart Waite

Hi OZ928S4
That is a really fantastic offer - thanks a million. The part I need is the lower
idler mounting bracket 928.105.961.1R
I've had a closer look at mine and it mounts on two 8mm steel pins set at 33.mm centres, however whilst the left hole is a nice sliding fit on the pin the right hole is badly worn with an ID that varies from 8.3mm at best to about 9.1mm at the point of most wear. I'm planning to get a local machine shop to bush the hole for me unless I can get hold of a new or good condition replacement.
Thanks again
Regards Stuart

Stuart Waite

Hi Landseer
Not quite sure what you are asking. I really don't know what or where to measure and I have no figures to compare any results against. All I can tell you is that the right hand of the lower two idle rollers can float vertically by 2-3mm and makes a clear tap tap as it does so when the carrier is oscillated by hand. I am making a huge assumption but I think that any movement at all is way too much as I think the carrier should probably not move at all!

Bill Ball

Or as mentioned, if you install the Porkensioner, just pull that lower idler assembly off. In the meantime, if that is the source of the noise, you could just ignore it, as long as it isn't so loose it could jam somehow, and it doesn't appear to be that bad from your measurements. With the belt properly tensioned, that idler is not critical.

Stuart Waite

Hi OZ928S4
Sorry there was a typo in my last post. The part no of the lower
idler mounting bracket I actually need is 928.105.561.1R

the flyin' scotsman

Stuart...............given the work you have already done I'd suggest buying a belt tension tool and doing the belt tightening to spec. John Speake has them in your part of the world.

Also, if the lower idlers are the issue pull them off and run the engine............you'll soon determine if thats the concern.

With the new water pump it probably came with a new pin for the roller arm which should be mated to new bearings.

Installing the Porkensioner eliminates all the idlers rollers (3), the bearings and the main roller arm..........quite a savings in money and maintenance.

oz928s4

That is the number alright
Did you need the wheels with it.
Let me know where you are and i will get a price to ship to you.
Should be around 10-15 USD

Stuart Waite

Hi oz928s4
Nobody in the UK seems to have one of these and my search for a machine shop to refurbish mine seems to have drawn a blank so far :-(
My Address here in UK is :-
Southside
Livesey Avenue
Ludlow
Shropshire
England
SY8 1HN
I really appreciate your offer, you are an absolute star
Regards
Stuart