pcar928fan

Believe Wally. Remember HE IS YODA!

I would also add that the Euro S engines are almost certainly interference engines as well...

Brian, the question is the US 4.7L engine...there have been some situations where a belt break (or something) resulted in bad things hitting each other...MANY other times where there were no problems. Hence Wally's answer is best, but folks have got away with belt breaks more than a few times on US 4.7L engines.

As for me, I drive none of my cars all that often. About a year ago I got to thinking it has been awhile since my last belt changes so I started looking... YES IT HAD! 12 YEARS and 35k miles I guess on my '88 S4, 11 YEARS and 15k miles on my '94 GTS, and god only KNOWS how long on my '92 GTS...I had owned the car about 10 years then and I had NEVER done it! Needless to say I had a lot of TB changes on the books last year.

That said, my cars live in a garage and as noted don't see a lot of drive time and almost NONE of it in traffic so they don't get quite the abuse than a DD car would get. I was lucky. My S4 actually gave me the T-belt warning light a few times before I put the new belt on...thank goodness for that!

Calgary Ole

I just replaced my first TB last month. I will change it every few years as it is quite easy to replace, and I get to clean and check for possible issues before they apprear. Also I used the Porken Tensioner which is working quite well.

jayc67

Well I may be gambling and playing with fire but I just did a TB tension check at 5 years and I'm not going to fool with the belt right now

My car is 12,000 miles and 5.5 years from it's last TB change.

Tension was good, tensioner was still OK and had not leaked the oil out, belt condition appears very nice all the way around. Can still read most of the lettering on the backside.

I'm just gonna keep on going. I'll look again in another year.

5 years as a hard rule, for how I store the car and how I drive it, just seems too soon.

I'm also moving over into the "if the waterpump is working leave it alone" camp.

The important thing in my opinion is to keep a close eye on it regardless.

Opening up the passenger side and checking condition and tension is very easy, so that's a yearly thing for me.

rluvsporsche

If your car or you are still around

Hold On

I bought a low mileage (60K) 83S about a year and a half ago. I read all about the TB and decided to take a look. This was the original belt still on car. At first look the belt looked fine.No rounded teeth, nice clean edges, cam gears looked good. After looking closer, it was filled with small hairline cracks and was not going to last long. Miles was not the big issue. TIME had taken its toll on all of the rubber parts in there. 25 yrs is a long time no matter how few miles the car has.

mirousse

I bought my S4 at 118000km. PO guaranteed the TB job has been done but he had no proof. I had visually inspected the whole belt and checked the tension at the beginning and ending of the driving season for 2 years.

During that period, I hadn't found signs of stress on the belt but rather I had found signs of stress on me! Mecanic is not a matter of faith! It has physical limitations mitigated by maintenance. The risk of failure is present and increases as you reach the lowest mileage interval for a 928 TB failure. If it has never happened under 60K, so be it. If it did at 45k, then 45k it is!

Changing the TB is an 18 hour and 350$ worth of part job (DIY). Nothing compared to a TB failure. If money is no object for some, just loosing the ability do drive and enjoy the car is worth doing the maintenance, even before Porsche says so.

I did my first TB replacement job in last November. I saw signs of a past replacement by the PO. However, the rollers weren't changed: The larger had the securing bolt gone. It was grinding against the crank shaft ring and being softer, the roller was becoming narrower (1/3 was gone - The ring is OK) Also, the smallest roller was seized. It's also a good opportunity to clean the engine and see for yourself how beautiful is this engine...a piece of art!

davek9

This is so true, I worked on a friends ’86.5 Euro this past Fall, he had all the paper work that showed a new Tensioner was done from the Porsche garage.
Yes there was a new Tensioner and that was the only thing they replaced.

They did not change the nylon Tensioner bushings and the Tensioner Arm was wobbling and causing the belt to drift back and forth on the Cam Gears.

It is always good idea to see for yourself if you can and be sure all the ware parts are replaced, and not just the big ticket items.

jayc67

I'd like to hear more about where this 5 year business came from.

Seems to me it is just a SWAG based on the long accepted industry average of 12,000 miles a year being "normal" driving. That happens to line up nicely with the recommended 60k mile replacement time.

Was there more reason for the 5 year limit? Was there an actual increase of failures at the 5 year mark?

For most of us it seems the age is what we run into long before the miles and 5 years just seems on the extreme side of caution, even at $350 for DIY. But, I have no "evidence" either way, just wondering if there is any.

ROG100

The timing belt and all moving parts and seals should be changed every 3000 miles or 3 months whichever somes sooner.

NOTE: Never listen to a salesman who is the 928 parts business and has teenage girls about to go to college

GregBBRD

And you need to use the $110 CRP belt that is only available in 6 packs!

Lizard928

Rog that is funny!

I ran a belt on my car with extreme use (no covers). It was a 32V 86 engine, so had the higher lift cam. I ran it for 6 or 7 years on the same timing belt always checking it for signs of wear. There were none that justified its replacement. I took it off just this year as I am rebuilding the engine.
The belt was still fine. I had way less than 60k on it though.

I have done 944s that I doubt would have made it another 50 miles though......