View Poll Results: Have you had any of the following failures
Timing belt failure
15
23.08%
Counter shaft belt failure
8
12.31%
Cam chain tensioner failure
3
4.62%
Does your engine have 8 valves?
27
41.54%
Does your engine have 16 valves?
12
18.46%
Voters: 65. You may not vote on this poll
Poll - T Belt, Ctr Shft Belt, Tensioner Failure Poll
#16
My 944S had 110,000 miles on it when the cam chain broke. Amazingly, it must have broken when the car was being shut off or started up because it was running just fine. Went to start it up, and it wouldn't fire. The power of the starter motor must have bent several of the valves.
IMO, I don't think putting the clutch in, or shutting the car off within a milisecond would prevent damage to the valves.
So I had the head rebuild and sold it. Great looking and fun car... just not enough power, IMO.
Erick
IMO, I don't think putting the clutch in, or shutting the car off within a milisecond would prevent damage to the valves.
So I had the head rebuild and sold it. Great looking and fun car... just not enough power, IMO.
Erick
#17
Originally Posted by RSAErick
... just not enough power, IMO.
Erick
Erick
Jon
#19
This makes me nervous. I just came inside the house after completing a WP/belt job. I tensioned all the belts, but the job always makes me uneasy. Hopefully I will have nothing to contrbute to this thread/poll.
#20
I put down timing belt failure, although it in my case it was really an automatic tensioner failure. I was driving home from the repair shop after a major servicing, (which included a new waterpump, belts and rollers), and going up a hill the timing belt skipped a tooth or two and ended up bending a couple of exhaust valves.
The shop fixed everything on their nickle, except for a new tensioner. I was quite P.O.'d, as they had charged me extra during the original servicing to remove, clean, and bench-test the old tensioner (it was making funny noises, and didn't seem to set the tension properly, they said). Hello!?! If there was any question about the old tensioner, they should have replaced it. They should have at least asked me before they put the old one back in. I certainly would have been willing to spend the money for a new tensioner if there was any doubt about the old one.
After the head job was done (took them a few weeks!), I drove the car home (60 miles) and went over their work carefully. I noticed several bolts missing, and a few other bolts that were loose on various parts that they had removed and replaced. Did not make me happy. I checked as many of the bolts and fasteners as I thought they might have touched, and tightened everything up. I must have missed a few, as a few weeks later I notice the A/C is not working anymore. Turns out the bolt on the power steering pump tensioner vibrated out, and allowed the pump to bump into the R134A adapter on the A/C compressor low side fill valve. This cracked the valve on the compressor - one compressor, Toast.
OK, it gets worse. Not only is my A/C now fubar, but when I go to a different shop later to get some work done on my car, they notice that the new timing belt tensioner is cracked, presumably from being over-tightened. Of course, I can't prove the other shop was responsible, so there is not much I can do.
I better stop now, before I burst a blood vessel. It is for these reasons that I do my own work now! I really can't believe that a "reputable" shop such as the one I went to could do such sloppy work.
Keith
The shop fixed everything on their nickle, except for a new tensioner. I was quite P.O.'d, as they had charged me extra during the original servicing to remove, clean, and bench-test the old tensioner (it was making funny noises, and didn't seem to set the tension properly, they said). Hello!?! If there was any question about the old tensioner, they should have replaced it. They should have at least asked me before they put the old one back in. I certainly would have been willing to spend the money for a new tensioner if there was any doubt about the old one.
After the head job was done (took them a few weeks!), I drove the car home (60 miles) and went over their work carefully. I noticed several bolts missing, and a few other bolts that were loose on various parts that they had removed and replaced. Did not make me happy. I checked as many of the bolts and fasteners as I thought they might have touched, and tightened everything up. I must have missed a few, as a few weeks later I notice the A/C is not working anymore. Turns out the bolt on the power steering pump tensioner vibrated out, and allowed the pump to bump into the R134A adapter on the A/C compressor low side fill valve. This cracked the valve on the compressor - one compressor, Toast.
OK, it gets worse. Not only is my A/C now fubar, but when I go to a different shop later to get some work done on my car, they notice that the new timing belt tensioner is cracked, presumably from being over-tightened. Of course, I can't prove the other shop was responsible, so there is not much I can do.
I better stop now, before I burst a blood vessel. It is for these reasons that I do my own work now! I really can't believe that a "reputable" shop such as the one I went to could do such sloppy work.
Keith
#22
Originally Posted by Keith Weller
I really can't believe that a "reputable" shop such as the one I went to could do such sloppy work.
Keith
Keith
Dfleko, saw your post on your thrown rod, so sorry.
Rock, Glad you can read, actually it has only been 8.5 months...
Jon
#23
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Joined: Sep 2003
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From: Under Your Car
I had a timing belt failure because the PO removed the timing belt idle roller, and i wasnt smart enough to check the belts myself since he said he just did them
oh and i got lucky with only 1 bent valve
oh and i got lucky with only 1 bent valve
#25
My Humbling Experience
Does timing belt skip qualify? I would think so, because the damage to the engine was the worst I have seen....and the timing belt was INTACT! My 1986 944 NA 8V was doing 75mph on the freeway one hot August afternoon- I hear a quick screeching sound, followed by a faint "pop", then "pssssshhhh", as huge black clouds of smoke screen the entire freeway behind me. I stop on the shoulder, bowing my head in embarrassment- as all the people I passed earlier, laugh by me.
Fearing TB failure- I open the hood and remove the upper timing cover. Its still sitting pretty. WTF?
I try starting again, and the engine seizes. I lose sleep all week, wondering how a car goes totally non-op, and still have the timing, balance shaft belts intact. Instead of towing the car to a Porsche Independent- I borrow a cherry-picker, and attempt to perform my very first engine removal. The suspense is killing me. After struggling for three days to remove the motor from above....the engine is finally out- at the cost of a radiator, oil pan, and distributor cap/rotor. Externally, the engine is a greasy, grimy mess. Inside is another story:
After pulling the head off- chocolate malt just permeates everywhere. I look at all the pistons and see nothing but a dark hole in the #4 cylinder. The combustion chamber below the head shows multiple valve indentations in the #4 bank, like an intake valve snapped off, and bounced around before the #4 piston explodes. And, explode it did. I see ferrite-coated nuggets of aluminum piston in the oil pan, intake manifold...even inside the headers! Coffee colored oil/coolant shake is vomited through every vacuum/breather hose, including the air filter. The synopsis? Being a new Porsche owner- my laziness, and outright ignorance killed this fine car. I had the timing belt done, after buying the car- but never realized an adjustment was necessary. The belt obviously stretched to a point where morning starts took 30 minutes of constant cranking, re-cranking, wait....crank-again, etc. before starting(off-timing when cold). It ran great- when started. The whole time I thought the valves needed adjustment...(sic!) The heat combined with a maxed-out, extended belt, decided to crack a revolution like a whip once and retarded the timing 5-6 teeth back, when decelerating(I remember it clearly)on the freeway, at 75mph. A valve collides with the piston, shearing it clean off the valve keepers, and hackey-sacking it until the piston shatters, raining heated aluminum shrapnel, oil, and coolant through every orifice it can escape. The #4 cylinder wall crumbles from this, and pieces of it make way to the intake tubes. Since then- I have graduated from automotive school, and I am back to learning again....
Zach
Fearing TB failure- I open the hood and remove the upper timing cover. Its still sitting pretty. WTF?
I try starting again, and the engine seizes. I lose sleep all week, wondering how a car goes totally non-op, and still have the timing, balance shaft belts intact. Instead of towing the car to a Porsche Independent- I borrow a cherry-picker, and attempt to perform my very first engine removal. The suspense is killing me. After struggling for three days to remove the motor from above....the engine is finally out- at the cost of a radiator, oil pan, and distributor cap/rotor. Externally, the engine is a greasy, grimy mess. Inside is another story:
After pulling the head off- chocolate malt just permeates everywhere. I look at all the pistons and see nothing but a dark hole in the #4 cylinder. The combustion chamber below the head shows multiple valve indentations in the #4 bank, like an intake valve snapped off, and bounced around before the #4 piston explodes. And, explode it did. I see ferrite-coated nuggets of aluminum piston in the oil pan, intake manifold...even inside the headers! Coffee colored oil/coolant shake is vomited through every vacuum/breather hose, including the air filter. The synopsis? Being a new Porsche owner- my laziness, and outright ignorance killed this fine car. I had the timing belt done, after buying the car- but never realized an adjustment was necessary. The belt obviously stretched to a point where morning starts took 30 minutes of constant cranking, re-cranking, wait....crank-again, etc. before starting(off-timing when cold). It ran great- when started. The whole time I thought the valves needed adjustment...(sic!) The heat combined with a maxed-out, extended belt, decided to crack a revolution like a whip once and retarded the timing 5-6 teeth back, when decelerating(I remember it clearly)on the freeway, at 75mph. A valve collides with the piston, shearing it clean off the valve keepers, and hackey-sacking it until the piston shatters, raining heated aluminum shrapnel, oil, and coolant through every orifice it can escape. The #4 cylinder wall crumbles from this, and pieces of it make way to the intake tubes. Since then- I have graduated from automotive school, and I am back to learning again....
Zach
#26
Originally Posted by Dilberto
I had the timing belt done, after buying the car- but never realized an adjustment was necessary. Zach
I was screwed by the PO who advertised that the new owner would not need to worry about belts because they were all new. He did not tell me that they had not been re tensioned until I was in his front yard ready to drive the car home from Washington. I decided to take the chance. From his emails following the belt breaking the car had about 1800 miles since the belts were replaced.
#27
my contribution to this poll is a chain tensioner failure. jon - you and i corresponded before regarding the tensioner. i feel your pain (although i got off cheap at $3100. now i'm rebuilding the entire engine. you can count spun rod bearing in my list of problems with this car.)
zach - you've got some talent for descriptive narrative. i read your story with interest (and pity)
zach - you've got some talent for descriptive narrative. i read your story with interest (and pity)
#28
I clicked the 8v choice, no failures but I had a close call I guess.
I was at a buddies house hanging around, and had to move my car. I move it, and his dad notices a small puddle of coolany on his newly resurfaced driveway. After getting slightly worked up over this, he and I jacked the car up and tried to figure out the source of the leak. Couldnt figure it out for sure, I was hoping for a small hole in a hose, but deep down I knew it was the pump. I had belts done when I bought the car, but passed on the waterpump in the same job due to the FREAKING OUTRAGEOUS price. $700USD for the belts alone, to include the pump would have been $2000USD TOTAL.
Of course, the pump bearings are toast after the few thousand miles I put on the car, so it starts leaking. I drive it for another few days (took it to shop to get them to confirm thatt his is the problem, and to buy parts),
I get the pump out of the car, and spin the shaft by hand... Grinding noise and a roughness for 1/4 or so of the rotation I got very very lucky I think...
Edit: Asides from the pump, no engine problems at all. Only oil leak *seemed* to be the pressure sensor, doesnt seem to burn much oil (just some blowby, no clouds/puffs of smoke tho), and pulls like a mother I think. My other problems have ranged from a dead starter, blown CV joint, shot tie rods, ball joints, caster blocks, what seemed to be a SERIOUSLY blocked up rad, etc etc etc.
I was at a buddies house hanging around, and had to move my car. I move it, and his dad notices a small puddle of coolany on his newly resurfaced driveway. After getting slightly worked up over this, he and I jacked the car up and tried to figure out the source of the leak. Couldnt figure it out for sure, I was hoping for a small hole in a hose, but deep down I knew it was the pump. I had belts done when I bought the car, but passed on the waterpump in the same job due to the FREAKING OUTRAGEOUS price. $700USD for the belts alone, to include the pump would have been $2000USD TOTAL.
Of course, the pump bearings are toast after the few thousand miles I put on the car, so it starts leaking. I drive it for another few days (took it to shop to get them to confirm thatt his is the problem, and to buy parts),
I get the pump out of the car, and spin the shaft by hand... Grinding noise and a roughness for 1/4 or so of the rotation I got very very lucky I think...
Edit: Asides from the pump, no engine problems at all. Only oil leak *seemed* to be the pressure sensor, doesnt seem to burn much oil (just some blowby, no clouds/puffs of smoke tho), and pulls like a mother I think. My other problems have ranged from a dead starter, blown CV joint, shot tie rods, ball joints, caster blocks, what seemed to be a SERIOUSLY blocked up rad, etc etc etc.
#29
So far, I have been fortunate, and have not had any of those problems raise their ugly heads. I have proactively replaced them all, however, when a couple of water pumps ceased to function.
Zach, I'll second Joseph Mitro: you are a gifted writer! I am going to have to read some of your previous posts! Have you ever thought of writing for an automotive magazine?
Zach, I'll second Joseph Mitro: you are a gifted writer! I am going to have to read some of your previous posts! Have you ever thought of writing for an automotive magazine?
#30
Josef, You certainly have had your share with your S. I was shop talking with another 944 enthusiast and he said 944 rod bearings last about 140k miles. Is that about what you had on your car?
I saw your post about not getting the engine off the drive shaft. Glad you got out of that one. Glad you are keeping the faith and don't get too friendly with that M3.
Jon
I saw your post about not getting the engine off the drive shaft. Glad you got out of that one. Glad you are keeping the faith and don't get too friendly with that M3.
Jon
Originally Posted by joseph mitro
my contribution to this poll is a chain tensioner failure. jon - you and i corresponded before regarding the tensioner. i feel your pain (although i got off cheap at $3100. now i'm rebuilding the entire engine. you can count spun rod bearing in my list of problems with this car.)
zach - you've got some talent for descriptive narrative. i read your story with interest (and pity)
zach - you've got some talent for descriptive narrative. i read your story with interest (and pity)