Timing Belt replacement

[D-D]

I'm new to the 924 world and I've got a question regarding the replacement of the timing belt. My 87 924s had the timing belt replaced about 15-17K miles ago before I got the car. I've seen the paper work and the replacement was done by a reputable shop. The water pump and rollers etc were replaced so I'm confident the work was done right at that time. And the car was taken back to check the tensioning.

My question is I understand that mileage wise the belt should still be good, but how often should the belt be changed time wise? Also is there a simple way to check the condition of the timing belt?

[944 S2]

Basically every 5 years

[944 Ecology]

Originally Posted by D-D

My question is I understand that mileage wise the belt should still be good, but how often should the belt be changed time wise? Also is there a simple way to check the condition of the timing belt?

The simple, but expensive way, is to not replace it at 30K miles or 5 years (whichever comes first), and hold your breath every time you go to start it.

Short answer: doing it ten times too often over the life of the car is cheaper than letting it fail once. Ask me how I know...

[Alexb944]

well... how do you know.. lol im jk... I spent 1500 on parts and tools to replace myself.. ive never had one fail but i think replacing mine every 30 is cheaper still.

[Jfrahm]

I do not think belt age is a big factor myself, they are not out in the sun or exposed to a lot of ozone. However the 8v 944 belt is runty and more problematic than most belts, it also does not have a dynamic tension system that might reduce stress on it.

I have cars which had 12-15 year old timing belts on them and they did not break, in some cases they were even in decent shape when I replaced them. I do not think 10 years is a lot of years for a modern timing belt.

Doing the belt only on an 8v is not that hard nor expensive so I'd probably change it at 10 years or due to mileage or if I was in there doing something else.

The worst timing belt I've handled was 13 or 14 years old and had 180K miles on it, I bought the truck in that state and changed the belt right away. The belt was pretty dry and leathery. Someone on an Audi forum just had one let go I think at 170K and 15 years.

Tension is a big deal with the 8V and non-968 16v belts, it's important to retension them and not run them too tight, all bets are off if they are stressed badly. When you change the belt it's very important IMO not to put them on stupid tight and to re-tension them after they bed in. It's spooky how loose they get when they wear in and I like to retension after only 100-200 miles and then again at the recommended 1st interval, plus I want to see how the rollers are doing and how it's tracking, look for drips, etc.

-Joel.

[v2rocket_aka944]

due to 944 belt routing and "thin-ness" they don't live a very long life.
i have pulled off 3 year old, 30k miles or less belts that literally groan as you turn the crank by hand because they were so dried out, cracks starting to form.

be sure to change all the rollers/idlers with the belt as well - if you don't, you are begging for a belt failure. 944 timing/balance belt rollers are only good for one belt interval - the bearings are SHOT by the 3-4 year mark.

[Bradical]

The best advice is to change the belts and idlers NOW, mostly because you'll realize how easy it is to do and check regularly. That'll relieve the anxiety.

[Jfrahm]

Belt maybe. I however feel that a good part, installed and well within it's service life, is better than installing a new part. A new part could be faulty, it could be counterfeit, the threads could pull, it could come loose, etc. In the case of a water pump there are other failure modes. A good quality roller should go 50K-100K miles easily and often longer. If some are failing early as suggested above they may have been victims of a hamfisted belt or something.

It's a fine thing to get past the infant mortality stage with a new part and into the fat part of the lifespan bell curve.

On the other hand if it is going to cause anxiety and you can't get past it (sell your 944 and buy a Corrola or) replace the parts and do the job right and sleep slightly better. Otherwise take that time and effort and fix your starter wiring before your car drives through the back of your garage, or fix the fuel lines before it burns up, or...

...maybe do that stuff too either way. I'm serious.
-Joel.

[v2rocket_aka944]

Originally Posted by Jfrahm

A good quality roller should go 50K-100K miles easily and often longer. If some are failing early as suggested above they may have been victims of a hamfisted belt or something.

then it seems INA (only supplier) does not make high-enough quality rollers.
NO 944 roller I have ever seen (on 40-50? cars I have done the belts on) has been good enough to continue using - maybe not totally dead, but noisy enough and loose enough to chuck in the ****-can, 100%.

[Jfrahm]

Crazy, my experience is that INA makes really good stuff. Ah well.

[v2rocket_aka944]

Originally Posted by Jfrahm

Crazy, my experience is that INA makes really good stuff. Ah well.

That's the thing - they DO make good stuff.
But something about the 944 belt arrangement KILLS these rollers that would live an easy long life on any other car.
My Subaru has a 60,000 mile belt interval, later models are 105k...

I wouldn't dare attempt that on a 944. 968 maybe, because it has the tension compensator and even Porsche said 60,000 miles for that model.

Simple fact of the matter...it is mandatory to swap rollers out with every 944 belt job. If not..."it's your funeral".

[D-D]

I think you guys told me what I suspected. Basically if in doubt do the belt. One other question about the belt replacement. Is it necessary or recommended to replace the water pump each time the belt is replaced. I don't want to be cheap but the water pump was done at the same time the belt was done about 15-18k miles ago. Apparently the pump was $200 at that time. So do I do the pump or save the $ for other repairs?

[944 Ecology]

Originally Posted by D-D

I think you guys told me what I suspected. Basically if in doubt do the belt. One other question about the belt replacement. Is it necessary or recommended to replace the water pump each time the belt is replaced. I don't want to be cheap but the water pump was done at the same time the belt was done about 15-18k miles ago. Apparently the pump was $200 at that time. So do I do the pump or save the $ for other repairs?

Leave it alone unless it is starting to leak or the bearing shows play when you turn the pulley.

[D-D]

Thanks for the info on the replacing of the water pump.

[D-D]

So I took the collective advice and had the belt etc replaced. I certainly feel much better not worrying every time I start the car. It had been 7 years since the belt was replaced. The water pump was also replaced.

I know it had to be done but spending about $1,500 and having the car perform the exact same afterwards is still hard pill to swallow.

[pdxfj]

Well.. look at it this way.. had the belt broken, you would still be out the $1,500 plus the cost of a head gasket, intake and exhaust gaskets and finally a head job with new valves.

I just replaced all my belts and rollers after 3 years and about 15k miles. Timing belt tensioner had started howling and the belt was squalling on the cam pulley.

[pfarah]

I've performed this service twice during the 5.5 years and 27k miles of ownership.

[curtisr]

Originally Posted by D-D

So I took the collective advice and had the belt etc replaced. I certainly feel much better not worrying every time I start the car. It had been 7 years since the belt was replaced. The water pump was also replaced.

I know it had to be done but spending about $1,500 and having the car perform the exact same afterwards is still hard pill to swallow.

You'll sleep better at night--believe me. One doesn't usually have reason to regret money well spent.

[D-D]

Curtisr I'm east of Peterborough. Any chance of getting together for a coffee? As I said I'm new to the 924 world and have a lot of questions. A road trip is always fun.