Porsche Enthusiasts Club Forum

Im about to change the balance belt timing belt tensioner and water pump. oil seals on the crankshaft too.

On a 1988 924S The whole car seems to be a 944 in a 924 shell from what i have seen, It has the spring style tensioner
160 bhp engine and ECU.

I need some advice on DIYing the above, i have watched a load of you tube movies which makes it seem not so bad a job.
The car is currently sorned and needs some light restoration. I bought it with no service history, so the belts is the must do job if anything.

It is exactly a 944 engine in a 924 shell. Audi stopped making the block for the 924's original 2.0 engine, so Porsche's only option was to drop in the 944 engine and call it an 'S' model.

You're fortunate to have the auto-tensioner, so you don't have to touch the belt once it's fitted.

I believe you will need a flywheel lock, fitting this involves removing the starter, and some sort of tensioning tool, although I have seen experienced mechanics do this by hand-feel alone.

I haven't done this!

Just finished changing my belts, rollers and pump on my s2 (tensioned it last night)

You will need the flywheel lock, depending how tight your bolt is, in my case i needed a large bar with a piece of scaffold tube on the end to undo mine, didnt fancy putting that much pressure on it with a screwdriver or punch jammed in the flywheel! After doing it I think there's a lot of scare mongering that goes on with doing these. It's not so different from anything else. I just takes a bit more time. The only thing is setting the tension with the gauge. Took me a while to get my head around it, in the end I've set it to what I think is right.
I plan on taking it to opc or an indie for the 1500 miles inspection and re tension.

Like you my car is sorn so I took a while over it popping in the garage for an hour or so some evenings, cleaning/ painting things as I go.

I took some pictures as I went, I'll post them in an earlier thread later on.

Rich.

Can someone explain why you need to undo the crank bolt?

Thanks for your comments, I originally bought a black 924 2.0. Thinking the whole balance belt thing sounded scary, 944 the same and too wide to fit in the garage. I later discovered to get what i wanted from my n.a. I should have bought an S in the first place.





The balance belt timing belt tensioner and correct tensions, is the main problem. I cant drive the car to have it serviced professionally, its not road legal. Doing it myself is the only option and will save money to buy a new water pump. i'll either do it right or ill **** it up. As such have decided to set the tension by feel alone, which i believe - is more accurate than a tool i'll most likely use incorrectly.

The crankshaft nut, needs to be undone in order to remove the crank pulley, in order to remove the timing cover back plate, to release the water pump (I think)

He wants to change the crankshaft seal, also access to the belts. You probably could wangle the timing belt past the balance pulley and the plastic guard but it makes it easier to have clear access to the timing pulley when youre fitting and setting up the new one.

The main bolt holds on the power steering pulley with no key (which is why it's so tight), then sandwiches the alternator pulley and balance pulley (bolted together with 4 Allen bolts) onto the main pulley.

yes i have a slight oil leak bellow crank pulley, today removed the starter motor so have commited myself to pulling the pulley.
Pleased i didnt shear off the small terminal was pretty rusty.

I have had the car running and it sounds good, but there is the classic belt whine, which i believe is the balance belt tension too tight.

http://www.youtube.com/watch?v=VFCXH3Ya5wU

The spring tensioner will get the cam belt near the correct tension, maybe on the tight side. You should be able to twist the cam belt through 90 degrees along its longest run.
The balance belt should be a fair bit looser, I suggest getting a feel for how it is installed at the moment.

It's your engine and your risk etc but I've always done them by feel and not had an issue.

The belts may whine at first but if it doesn't go away chances are the balance belt is too tight or the eccentric pulley is too close to the balance shaft. Worth measuring the existing gap between the two pulleys before pulling it apart.

Oops too slow.

Oh and its only the 968 style hydraulic tensioner that adjusts itself.

Thanks james thats very good advice. Before i begin taking the belts out etc, will have a good feel of the tensions as they currently are.

I have some good guides for touch and feel tensioning, from tutorials ive watched.



The gap between the balance idler and the balance shaft can be measured by using a credit card which is said to be the right clearance.











I will check for this when i get my covers off, prior to releasing the belt.

Bottom pulley is keyed on - this came off my '83. the bolt was only hand tight! You can see why the engine was vibrating a bit

can anyone reconmend a flywheel lock? i have seen people use alan keys?

This is the proper one: £

http://www.porscheshop.co.uk/acatalog/porsche_tools_tool_kits.html#a5186

Alex I have a set of Arnworx tools which Rich is returning at the w/e, As part of this box is a flywheel lock & and a Krikit tool. I live in Chatham you're welcome to collect & drop off.
Quite happy to lend them out, the deal is this. £100 cash deposit (the tools are probably £150 to replace), when it gets returned to me you get £90 back I put the tenner to charity. The box is damned heavy so shipping it will be expensive. The Krikit, spanner & flywheel lock are much lighter so we could ship these around, tracked if need be. These tools are mine & this is done outside of TIPEC.

As Rich has found out, you can get the balance shaft pulleys off using the old balance belt tightened up to lock them up. The crank pulley is FT & definitely needs a crankshaft lock. If the car has stood for a while then I'd change ALL four seals, (cam, crank & two balance seals). If the oil hasn't been changed too often then you'll need top hats as well, which are £24 each or so. Check all the idlers & tensioners, they are horribly expensive but Gates who make the belts do not recommend removal & refitting a belt that has been used, Porsche say it is acceptable. I wouldn't take the risk. The job isn't difficult but it is a lot of work, you struggle to do it all in a day, deffo not if the water pump needs doing as well.

Personally I'm happy with the Krikit tool to set the cambelt & would be happy with 90 Deg twist on the cambelt & 180 Deg on balance belt.
All belts whine, don't panic if you can hear them, new belts whine louder for around 2K before they settle.

Jim: great idea and a big help. I don't need them yet, but I had thought I would ask at my club meet when I do need these specialist tools. I'm sure members are keen to help each other.