avainio

I just replaced my belts, both were very loose but gave me no trouble. Who has actually had a broken belt and what were the circumstances? Interval since last service? Water pump history? Timing belt tensioner stud? Mileage? Please list anything you think is pertinent to what happened. It would be interesting to see if this is as common as it seems. I changed my belts based on threads from this board, and I'm glad I did. The timing belt roller bearing was rough and would have failed at some point.

Arne.

Oilslick964

When I had my 1992 968 cab the t-belt broke with 46k miles. Luckily, it broke just as I bumped the starter when I was starting the car. No valve damage, but I broke 2 rollers. Total cost to repair: $950. They replaced the rollers and put on a new timing belt. I felt like I was very lucky!

afx

about 2 weeks after I bought my car the timing belt broke. I bent 4 exhaust valves. I did all the work to fix it my self (except head work) and it cost about $1000.

afx

double post...

Jeff928S4

Bought the car with 125,000 Klms on it. Belts were changed last at 90,000....but it was 4 years ago. Only 35,000 klms on belts.

Belts made some "noises", but I wasn't educated enough on these cars to recognize the danger of that "loose" sound.

Bent 8 valves (all exhaust valves). Cost me $4500 Canadian to get it fixed, but I had some extra work done at the time.

944S Boyeee

Sean

Are there any instructions online for inspecting / changing 944 timing belts? A friend of mine recently changed his own on a 1992 300Z car. Definitely a time intensive project, but doable if you have thr right instructions.

I believe the timing belt broke on my car when it was owned by the previous owner. Of course, that just meant a lovely rebuild was in order. The car runs great now, but no doubt it took some effort (CHA-CHING) to get it running again.

The problem does seem to be fairly common. I recently looked at a 951 that just had a timing belt break. Cost $3500 to rebuild. Ouch.

Alpine951

<a href="http://www.clarks-garage.com/" target="_blank">http://www.clarks-garage.com/</a>

83Green944

T belt is actually pretty easy to change on these cars. I have never seen the belts in a 300Z before but I am assuming that these cars are alot easier.
As for an online instruction, check <a href="http://www.clarks-garage.com/" target="_blank">http://www.clarks-garage.com/</a>
There are a lot of informative articles on this site.

Danno

Interesting that the Porsche manual doesn't state an actual mileage to change the belts. They just say "inspect and replace as necessary". On my Z, Datsun says 60k-miles and Toyota indicates 75k-miles for the Supra (drives two cams no less).

I wonder if the open vent hole on a lot of people's cars were a contributing factor is contaminants getting in and stuff...

PorscheG96

The balance shaft belt on my 968 broke within the first couple weeks that I owned it. Gave me a nasty vibration between 3k and 4k RPM's but I was lucky that it didn't take out my timing belt. I had all belts/rollers/water pump replaced and had all that stuff replaced again after only 20k miles.

Bill

I had my timing belt break on my NA. The belts had 45,000 miles on them when they let loose. I could hear them slapping at idle but choose to ignore it. Bad choice, I bent all four exhaust valves. Cost me $900 in machine work to recondition the head and replace the valves. Another $100 in gaskets and misc. I did all the labor myself.

Since then, I have logged over 180,000 miles in my NA and 8,000 miles in my turbo, and have not broken any more belts. I change them promptly at 30,000 miles of use.

seb928s

I have had a timing belt tensioner fail because of the bearings blew out and it was fairly new too. The cost of the repair came out to be 700$ I did all the work besides getting the new valves in.

OC Porsche

I was looking to buy a local 928 a few years back and a buddy of mine decided to come with me. He is a car nut also (corvettes) and I figured, well 2 sets of eyes are better then one. The car was pretty rough for the interior but all the pieces were there and it was looking ripe for a great deal. I fired it up and ran it at idle for a couple of minutes and let my friend get in the seat while I looked over the engine. He was bouncing it around 3k rpm when I turned the corner to look into the engine compartment and saw a pulley and a shredded belt fly out. I was screaming my head off shut it down! shut it down! Over the horrific sound of that engine tearing itself apart he couldn't hear me very well and let off the throttle.....as soon as he did it died. When looking at the pully shaft, it had been jerry rigged and welded....well that broke. I offered 1000 bucks and he countered with 2K, I just about ran to the car before he could think about the fact that I just offered him money.....what a lifesaver my friend was. My friend also didn't realize that the engine was an interference design until I mentioned it, it was a quiet ride back to the neighborhood.

Jay W

Knew better and didnt do it soon enough. Bought the 924 with 160,000 miles and didnt know when the belt had been changed. Got 40,000 more miles and then got stuck in the center lane of the interstate in rush hour. Balance shaft belt broke and got wound up in the timing belt. Had to use the starter in first gear to get the car over next to the center divider so I wouldnt get smashed into by people on cell phones not paying attention. Only bent 2 valves and got by on $500 and two used valves doing the work (except machine shop) by myself. And I am a mechanic that warns customers all the time to change their belt at 60,000 miles.... I should listen to myself sometimes.

SamGrant951

When I first started driving my car I didnt know squat, drove it 2000 miles and bam, silent but deadly. Wouldnt turn over, flat-bedded to the 951 guy in town. Bent valves, the whole shibang.
Costly mistake, that said I quickly began reading about the quirks of the 944 series. Was the only time she stranded me since besides that pesky dme relay!
Shes due for belts/waterpump in a month or two.