Timing belt, fact or Internet folklore?
10-31-2015, 02:56 AM
#106
Rennlist Member
The belts for the 944 should be made on the same assembly line as the Honda and Ford belts.
All Gates, Conti, etc care about is the circumference (length) is right, and the tooth count and spacing is right.
The rubber, nylon cord, etc should all be identical to other belts...
Which means the application is causing the difference.
If the 944 had a hydraulic/dynamic tensioner, I would expect the belt to last to 60k like the 968 allowed for.
And I bet if the 944 water pump pulley shaft were extended out to be driven by the ACC belt instead, the timing belt would last to 100k miles like a "normal" car.
I am going to make a non-interference engine soon and intend to see just how long a belt lasts without being changed...stay tuned for updates in 2020.
All Gates, Conti, etc care about is the circumference (length) is right, and the tooth count and spacing is right.
The rubber, nylon cord, etc should all be identical to other belts...
Which means the application is causing the difference.
If the 944 had a hydraulic/dynamic tensioner, I would expect the belt to last to 60k like the 968 allowed for.
And I bet if the 944 water pump pulley shaft were extended out to be driven by the ACC belt instead, the timing belt would last to 100k miles like a "normal" car.
I am going to make a non-interference engine soon and intend to see just how long a belt lasts without being changed...stay tuned for updates in 2020.
10-31-2015, 11:22 AM
#107
Rainman
Rennlist Member
Rennlist Member
but I'm going to make one (retrofit hydraulic tensioner) happen on this next engine.When I have it figured out I'll post it here...it won't be 968 parts.
10-31-2015, 05:51 PM
#108
i just change mine every 3 years bc i can do it myself and doesn't take too long. doing the water pump however is a bit of a pain and i usually change out the pump every 3 years also bc from what i've heard a new belt can cause the old pump to leak. l
I have never used special tools to tension i just tension by feel and it has worked good for me. the 944 engine and timing belt system is not very complicated or difficult to replace
not sure if the timing belt would last much longer than 3 years i'm guessing it can last much longer but people replace it at 3 years to avoid a failure. on newer cars I think the belts go to 100k miles and 8-10 years between changes. when i change my belt at 3 years it still looks pretty new. I always use Gates belts as they just feel like better quality belts than some other brands like conti but i'm sure any quality brand is fine.
I have never used special tools to tension i just tension by feel and it has worked good for me. the 944 engine and timing belt system is not very complicated or difficult to replace
not sure if the timing belt would last much longer than 3 years i'm guessing it can last much longer but people replace it at 3 years to avoid a failure. on newer cars I think the belts go to 100k miles and 8-10 years between changes. when i change my belt at 3 years it still looks pretty new. I always use Gates belts as they just feel like better quality belts than some other brands like conti but i'm sure any quality brand is fine.
10-31-2015, 06:34 PM
#109
Rennlist Member
i just change mine every 3 years bc i can do it myself and doesn't take too long. doing the water pump however is a bit of a pain and i usually change out the pump every 3 years also bc from what i've heard a new belt can cause the old pump to leak. l
I have never used special tools to tension i just tension by feel and it has worked good for me. the 944 engine and timing belt system is not very complicated or difficult to replace
not sure if the timing belt would last much longer than 3 years i'm guessing it can last much longer but people replace it at 3 years to avoid a failure. on newer cars I think the belts go to 100k miles and 8-10 years between changes. when i change my belt at 3 years it still looks pretty new. I always use Gates belts as they just feel like better quality belts than some other brands like conti but i'm sure any quality brand is fine.
I have never used special tools to tension i just tension by feel and it has worked good for me. the 944 engine and timing belt system is not very complicated or difficult to replace
not sure if the timing belt would last much longer than 3 years i'm guessing it can last much longer but people replace it at 3 years to avoid a failure. on newer cars I think the belts go to 100k miles and 8-10 years between changes. when i change my belt at 3 years it still looks pretty new. I always use Gates belts as they just feel like better quality belts than some other brands like conti but i'm sure any quality brand is fine.
10-31-2015, 06:47 PM
#110
Three Wheelin'
Same here, it's really not hard to DIY the belts and the cost isn't all that bad. I don't use the special tension tool, I just go by feel. There's really nothing scary about the 944's timing system. If you've done belts on a few cars or bikes and have a feel for belt tension, I don't really think the tool is necessary.
I don't mind putting on the flywheel lock but it's just so far under the car which is tough in certain situations.
10-31-2015, 11:04 PM
#111
Three Wheelin'
I've done the belts + pump, but now I'm wondering if all I'm doing is the belts, can I do it without using the flywheel lock, and/or not removing the balance shaft belt gear on the crankshaft? I've heard you CAN install the belts with this gear still on, but how difficult is it really?
I don't mind putting on the flywheel lock but it's just so far under the car which is tough in certain situations.
I don't mind putting on the flywheel lock but it's just so far under the car which is tough in certain situations.
Cheers,
Mike
11-01-2015, 12:31 AM
#112
Rainman
Rennlist Member
Rennlist Member
I do a lot of 944 timing belts. The na/turbo you can slip the timing and balance belts into place without removing even the accessory pulley, just the belt covers.
16v need the accessory pulley to come off.
Flywheel lock is indispensable though for timing sake.
16v need the accessory pulley to come off.
Flywheel lock is indispensable though for timing sake.
11-01-2015, 03:37 AM
#113
i don't believe the 4 years is too long mantra.
no way. that's getting close to silly. i've also heard 3 years quoted on these forums for years. that's full on nuts.
no car's inherent design can be THAT UTTERLY WORTHLESS. not even a 944.
if you can wrench, and it makes you feel good.... you have carte blanch.
the first owner of my '87 944S and me put 116k miles on a set of gen 1 belts over about 8 years
(i purchased the car in 1989 with 17 k miles w/ the original belts).
62k on another (on my 968) on long-life Gates belts. the belts came out of the car pristine.
then again, EVERYTHING was done when they went on.... new bearings/nothing dragging.
guess what, when they came off the car, the bearings were all tired. they were done (MEXICO BABY).
56k on still another (968) set of Gate's belts. Gates belts are designed for long life. they work as advertised.
4 years and low~moderate miles? bullsh t.
6, 7, 8 years? maybe. rotating parts? yes, the plastic gets brittle. 5 years is probably time.
outside of that, if the sh t is seriously, that bad, that belts break in 4 years, then the engine is a bullsh t failed design.
i don't believe the 944 engine is a failed design.
but i do believe it's a highly flawed design.
run Gates belts, along with NEW EVERYTHING for crying out loud - and retension them @ ~1500~2000 miles or whatever...
and you should be fine.
EXPENSIVE? yes. welcome to Porsche. (they planned it that way so the dealers wouldn't scream about lost 911 sales).
it's a flawed design. but not a lemon.
once and for all - it's not the Goddamned belts. ITS GOING CHEAP ON THE OTHER CRAP.
that includes rebuilt pumps. don't do that.
GO AHEAD, BE CHEAP. YOU'LL PAY LATER.
no way. that's getting close to silly. i've also heard 3 years quoted on these forums for years. that's full on nuts.
no car's inherent design can be THAT UTTERLY WORTHLESS. not even a 944.
if you can wrench, and it makes you feel good.... you have carte blanch.
the first owner of my '87 944S and me put 116k miles on a set of gen 1 belts over about 8 years
(i purchased the car in 1989 with 17 k miles w/ the original belts).
62k on another (on my 968) on long-life Gates belts. the belts came out of the car pristine.
then again, EVERYTHING was done when they went on.... new bearings/nothing dragging.
guess what, when they came off the car, the bearings were all tired. they were done (MEXICO BABY).
56k on still another (968) set of Gate's belts. Gates belts are designed for long life. they work as advertised.
4 years and low~moderate miles? bullsh t.
6, 7, 8 years? maybe. rotating parts? yes, the plastic gets brittle. 5 years is probably time.
outside of that, if the sh t is seriously, that bad, that belts break in 4 years, then the engine is a bullsh t failed design.
i don't believe the 944 engine is a failed design.
but i do believe it's a highly flawed design.
run Gates belts, along with NEW EVERYTHING for crying out loud - and retension them @ ~1500~2000 miles or whatever...
and you should be fine.
EXPENSIVE? yes. welcome to Porsche. (they planned it that way so the dealers wouldn't scream about lost 911 sales).
it's a flawed design. but not a lemon.
once and for all - it's not the Goddamned belts. ITS GOING CHEAP ON THE OTHER CRAP.
that includes rebuilt pumps. don't do that.
GO AHEAD, BE CHEAP. YOU'LL PAY LATER.
also changing pumps every three years is kind of insane on all other cars water pumps go for about 100k miles and people don't put in new water pumps every three years. I have heard from some that you can change the pump every other belt change but then others will tell you that a new belt will cause your old pump to leak and you should replace the pump also.
I think rebuilt pumps can be good or bad. I put in 2 bad rebuilt pumps in a row (both leaked right after the install) and then i got a rebuilt GEBA pump which is a company that does rebuilds in germany and it has been going for 3 years now without problems but i have no idea how long it will last. i think a rebuilt pump can be as good or better than new pumps if it is rebuilt properly and good quality bearings and seals are used. the geba pump that i have has some bad review on bmw boards and people claim they are crap and fail pretty quick but i've been lucky so far.
11-01-2015, 03:43 AM
#114
oh and when i bought my 944 around 8 years ago some people on forums tried to scare me from buying a 944 by telling me that the belts are really expensive to change and difficult and you require a 700 dollars porsche tool to tension it properly. not true at all.
for tension i use the twist and water pump method. the water pump method requires you to tension the belt so that at tdc you can twist the water pump pulley using one hand with some force. if you can't turn the water pump pulley at all with force it is too tight and if the pulley moves easily then it is too loose.
for tension i use the twist and water pump method. the water pump method requires you to tension the belt so that at tdc you can twist the water pump pulley using one hand with some force. if you can't turn the water pump pulley at all with force it is too tight and if the pulley moves easily then it is too loose.
11-01-2015, 07:41 AM
#115
Three Wheelin'
11-03-2015, 07:23 AM
#116
Rennlist Member
I am approaching 3 years again with new belts, rollers and a rebuilt pump all installed almost 3 years ago. I can't decide whether to change everything soon or to just slap a new belt on there or to just leave it for another year or so.
also changing pumps every three years is kind of insane on all other cars water pumps go for about 100k miles and people don't put in new water pumps every three years. I have heard from some that you can change the pump every other belt change but then others will tell you that a new belt will cause your old pump to leak and you should replace the pump also.
I think rebuilt pumps can be good or bad. I put in 2 bad rebuilt pumps in a row (both leaked right after the install) and then i got a rebuilt GEBA pump which is a company that does rebuilds in germany and it has been going for 3 years now without problems but i have no idea how long it will last. i think a rebuilt pump can be as good or better than new pumps if it is rebuilt properly and good quality bearings and seals are used. the geba pump that i have has some bad review on bmw boards and people claim they are crap and fail pretty quick but i've been lucky so far.
also changing pumps every three years is kind of insane on all other cars water pumps go for about 100k miles and people don't put in new water pumps every three years. I have heard from some that you can change the pump every other belt change but then others will tell you that a new belt will cause your old pump to leak and you should replace the pump also.
I think rebuilt pumps can be good or bad. I put in 2 bad rebuilt pumps in a row (both leaked right after the install) and then i got a rebuilt GEBA pump which is a company that does rebuilds in germany and it has been going for 3 years now without problems but i have no idea how long it will last. i think a rebuilt pump can be as good or better than new pumps if it is rebuilt properly and good quality bearings and seals are used. the geba pump that i have has some bad review on bmw boards and people claim they are crap and fail pretty quick but i've been lucky so far.
Sometimes bad part reviews are more geared towards the car they work for. Could be a flaw in the design on the bmw that never got addressed. If you've had 3yrs of it working without flaw then I would continue as usual and replace it every other belt change.
11-03-2015, 08:27 AM
#117
Nordschleife Master
The reason a lot of water pumps fail after a belt change is improper tension of the belt itself. Most people shouldn't have a problem changing the belt every other belt change.
11-03-2015, 09:55 AM
#119
Nordschleife Master
11-03-2015, 11:31 AM
#120
I've done the belts + pump, but now I'm wondering if all I'm doing is the belts, can I do it without using the flywheel lock, and/or not removing the balance shaft belt gear on the crankshaft? I've heard you CAN install the belts with this gear still on, but how difficult is it really?
I don't mind putting on the flywheel lock but it's just so far under the car which is tough in certain situations.
I don't mind putting on the flywheel lock but it's just so far under the car which is tough in certain situations.