Another flywheel/distributor question
08-27-2001, 02:51 PM
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Another flywheel/distributor question
I've found a very clean '90 C4 with 100K miles. The owner (2nd) says all major service has been performed (recent 90K service) and had an inspection done recently. The inspection came back fine, no major problems-small oil leak. The car still has the original flywheel and distributor belt as far as the owner knows. Is this possible that these two items have survived this long?
Is the dist. belt replaced automatically at some service interval?
Also, the clutch has about 20K miles on it.
Is the dist. belt replaced automatically at some service interval?
Also, the clutch has about 20K miles on it.
08-27-2001, 03:03 PM
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My 91 C4 broke the distributor belt at just over 60k. 100 k is not unknown, particularly if the distributor ventilation kit has been fitted.(part number 000 043 202 52) This should extend the life of these belts.
08-27-2001, 07:05 PM
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John,
If the owner has the records for the clutch , it should say if they changes the flywheel from the FDMF to the LUK.
If he didn't do the dist belt yet I would get Steve at Rennsport to do it as soon as possible and use it as a negotiation point.
If the guy doesn't have the records - be suspicious. By the way - who did you have do the PPI ?
If the owner has the records for the clutch , it should say if they changes the flywheel from the FDMF to the LUK.
If he didn't do the dist belt yet I would get Steve at Rennsport to do it as soon as possible and use it as a negotiation point.
If the guy doesn't have the records - be suspicious. By the way - who did you have do the PPI ?
08-28-2001, 02:58 AM
#4
John:
Yes, it's very possible they could both last that long. We know the distributor belt can be a problem, but I've never seen enough data or reports to get a "feel" for an average time/mileage when they break. A vent kit will prolong the life, but it's still a belt. Porsche really should have specified some type of replacement interval for this. Maybe they did and no one is aware of it.
As far as the DMF goes, I had a lengthy discussion about these with Roland Kunz, who posts here from Stutgart occasionally. He told me a fairly long story about the QA problems that Freudenberg was having with the flywheel, and if I understand correctly, Freudenberg actually got to a point where the testing procedure prior to release was unbelievably meticulous. As a result, I think it's safe to assume that some of the Freudenberg's will be better than others. Roland also pointed out that the Freudenberg doesn't like high performance driving too much (NOT a good thing on a high performance car!). If the previous owner was "light" on the flywheel...no hard acceleration and kind of what I guess I'd call "typical commuter driving" it would likely prolong the life of the Freudenberg.
Most of the information I've received about Freudenberg failures has been from a local PCA site when I was still checking out cars. Needless to say, I think the average PCA member is likely an enthusiast and likely to push the car a little more than most...but not necessarily race it. If I had to guess, I would say a typical Freudenberg failure occurs before 50K miles, but I've heard of some running on them well beyond 100K miles. There are a lot of variables in play here (mileage and age, driving style, and the fact Freudenberg had to implement more and more stringent tests/QA procedures) making it difficult to really say how long one will last.
It would be nice if we had some statistics to at least give us some guidance.
Where is John Miles anyway
Good Luck,
Bill Wagner
Yes, it's very possible they could both last that long. We know the distributor belt can be a problem, but I've never seen enough data or reports to get a "feel" for an average time/mileage when they break. A vent kit will prolong the life, but it's still a belt. Porsche really should have specified some type of replacement interval for this. Maybe they did and no one is aware of it.
As far as the DMF goes, I had a lengthy discussion about these with Roland Kunz, who posts here from Stutgart occasionally. He told me a fairly long story about the QA problems that Freudenberg was having with the flywheel, and if I understand correctly, Freudenberg actually got to a point where the testing procedure prior to release was unbelievably meticulous. As a result, I think it's safe to assume that some of the Freudenberg's will be better than others. Roland also pointed out that the Freudenberg doesn't like high performance driving too much (NOT a good thing on a high performance car!). If the previous owner was "light" on the flywheel...no hard acceleration and kind of what I guess I'd call "typical commuter driving" it would likely prolong the life of the Freudenberg.
Most of the information I've received about Freudenberg failures has been from a local PCA site when I was still checking out cars. Needless to say, I think the average PCA member is likely an enthusiast and likely to push the car a little more than most...but not necessarily race it. If I had to guess, I would say a typical Freudenberg failure occurs before 50K miles, but I've heard of some running on them well beyond 100K miles. There are a lot of variables in play here (mileage and age, driving style, and the fact Freudenberg had to implement more and more stringent tests/QA procedures) making it difficult to really say how long one will last.
It would be nice if we had some statistics to at least give us some guidance.
Where is John Miles anyway
Good Luck,
Bill Wagner
08-28-2001, 07:44 PM
#5
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Hello
Yes Bill we had some long threads about that and I try to simplifice it.
When Porsche designed the car they also where driving and testing the systems.
Now the test didnīt show any unusuall wear on the Freudenberg flywheel, the Bosch twindistributorbelt and the cylinderheadgasketsystem ( or the non gasket system ).
Porsche also had some datas from other companys and also the race engines had no gaskets since years and they had much more stress then a street engine.
However the prototype parts where not final and made by hand so the engenieers also said if the production starts the parts willbe refined and have even better datas.
Now that Porsche prototypetesting has different levels. One is drive max until something brakes. This is also known as rapid testing made on special tracks who stresses cars more then road use. Well known areas are Ehra Lessin, Nardo, Nürburgring, Zolder ( has fine sandmist ), Nevada, Alaska, Norway, Afrika and wherever they try to get into the worst. They donīt make this to have fun.
On the other side are testbenchruns. There are many benchs simulating typical drivings.
There is a hydropulserprogram that will drive a car trough New Yorks worsest streets in different climates and 24 hours/day.
All this data was needed to decide what parts to use and the coworking suplieers also tried to react onto those datas.
Now the Freudenberg units where very promissing and also BMW chossed them for there new engine generation. Freudenberg couldnīt deliver for the first cars as the machines to built the units hadnīt been built.
The Freundenbergunits showed no failures while they where built into the cars but after some months the falure rate rised and sure Porsche went out to nail the problem.
One was that the productionprocess wasnīt perfect enough and it wasnīt possible to find the bad units.
The Freudenbergunit is more then just a rubberelement baked between two flywheels and using silicon inside to dampen the frequency and help cooling.
One problem with the Freudenberg unit was if the drivers made drag racing they overheatet the unit and the rubber debacked ( debaclet ? )from the steelsurface ( burnt away ).
Those where the first returns and Porsche could repeat that on testruns. Porsche also had similar datas from testruns they made while they had the prototypes runing ( test to burst ). Porsche was to alarmed as missuse from the clutch is a problem from the user and before the Freudenberg other parts had blown up and so the issue was similar but shiftet from a soft pressure plate and blue parts to a defective DMF.
So Porsche surly made a task force to find a solution as the new coming engines ( Turbos ) where about the Freudenberg limits anyway. ( And under development in that time )
The dealers got a note that the problem is known and caused by the hard missuse. Now later Porsche had "strange" falures repotet from dealers, owners and also from the inhouse runing cars.
Those failures didnīt showed the typical overheating evidences and this startet the known history.
Short said the Freudenberg units had very good results at the prottypes but couldnīt fullfill the numbers on production. It was also hard to find out what caused the problem and to sort out the "risky" units while production so Freudenberg went a step down in there specs and millions where still on the road used by BMW making nearly nill trouble ( but maybe soon they will come ).
The distrubutorbelt is a similar story. Porsche had no falures as the parts never had enough time to age in the ozone. And also the first failures where delayed to the secound ownership when the people decided to save money and stretch the maintance. This leded to higher spark demand on the wide gaps and therfore the finger and cap burned up producing ozone. Also those people "couldnīt" afford to renew the caps and finger as they cost to much and the car also runs with the worn parts.
So both problems where hard to find in rapid testing and both elements where complete new in car world and therfore not enough long therm datas. Interesstingly both components are based on rubber and we all know that rubber will age. Porsche shurly was aware off that but didnīt thought the aging prozess will come so soon speeded up by random, heat and ozone.
Now I know 964 with more then 400000 km and still the first clutch including Freudenberg DMF and a retrofitet vent kit over the old rubber. As a mechanic my advise is allways to keep a godd maintance and drive as long as the parts will make no problem.
When the clutch is worn the cars get allways the update with the LUK DMF and the new TOB ( needing new guiding tube/fork ) as the old parts are not aviable anyhow. Could be that most Freudenberg DMF would have made a much larger lifespann but noone will bear the risk and I donīt like to work for free. Some costumers who are short on money or like to pocker still keep the old parts and still drive them. It is there choice.
On the distributor i usually exchange it with a upgraded one. That is the cheapest way fro a proffesional. But I also made the vent upgrade alone if the costumer wantet it.
From my own observation on a small basis I never had seen a failed belt. I had seen some at Bosch who informed there mechanics about typical first signs and how it can end in the worst. I also renewed sveral DMF but only two off them showed a failure. Both cars had a ultra low suspension and 18" wheels so maybe this is a better way to find a trouble car then looking on the odometer.
One couldnīt afford a new DMF and the upgrade and so whe "giftet" him a known old used DMF and this car is still driving, some 3 years later, around here. Still a happy costumer who loves his car andf one day will have the money to do the things right.
See Iīm not a Porsche mechanic focused on the cars. Iīm a mechanic on cars try to help the owners make there dream come true even if it isnīt perfect. Your local Porsche dealer maybe canīt do that.
One thing in germany is that most cars got upgraded as soon as possible and you will not find to much cars runing on the old parts.
Only very low milage garage queens have datet inerta and strangly some people pay more for a garage queen as for a complete updated wel driven in car who has only a 1 instead a nought on the 6th digit from the right.
Grüsse
Yes Bill we had some long threads about that and I try to simplifice it.
When Porsche designed the car they also where driving and testing the systems.
Now the test didnīt show any unusuall wear on the Freudenberg flywheel, the Bosch twindistributorbelt and the cylinderheadgasketsystem ( or the non gasket system ).
Porsche also had some datas from other companys and also the race engines had no gaskets since years and they had much more stress then a street engine.
However the prototype parts where not final and made by hand so the engenieers also said if the production starts the parts willbe refined and have even better datas.
Now that Porsche prototypetesting has different levels. One is drive max until something brakes. This is also known as rapid testing made on special tracks who stresses cars more then road use. Well known areas are Ehra Lessin, Nardo, Nürburgring, Zolder ( has fine sandmist ), Nevada, Alaska, Norway, Afrika and wherever they try to get into the worst. They donīt make this to have fun.
On the other side are testbenchruns. There are many benchs simulating typical drivings.
There is a hydropulserprogram that will drive a car trough New Yorks worsest streets in different climates and 24 hours/day.
All this data was needed to decide what parts to use and the coworking suplieers also tried to react onto those datas.
Now the Freudenberg units where very promissing and also BMW chossed them for there new engine generation. Freudenberg couldnīt deliver for the first cars as the machines to built the units hadnīt been built.
The Freundenbergunits showed no failures while they where built into the cars but after some months the falure rate rised and sure Porsche went out to nail the problem.
One was that the productionprocess wasnīt perfect enough and it wasnīt possible to find the bad units.
The Freudenbergunit is more then just a rubberelement baked between two flywheels and using silicon inside to dampen the frequency and help cooling.
One problem with the Freudenberg unit was if the drivers made drag racing they overheatet the unit and the rubber debacked ( debaclet ? )from the steelsurface ( burnt away ).
Those where the first returns and Porsche could repeat that on testruns. Porsche also had similar datas from testruns they made while they had the prototypes runing ( test to burst ). Porsche was to alarmed as missuse from the clutch is a problem from the user and before the Freudenberg other parts had blown up and so the issue was similar but shiftet from a soft pressure plate and blue parts to a defective DMF.
So Porsche surly made a task force to find a solution as the new coming engines ( Turbos ) where about the Freudenberg limits anyway. ( And under development in that time )
The dealers got a note that the problem is known and caused by the hard missuse. Now later Porsche had "strange" falures repotet from dealers, owners and also from the inhouse runing cars.
Those failures didnīt showed the typical overheating evidences and this startet the known history.
Short said the Freudenberg units had very good results at the prottypes but couldnīt fullfill the numbers on production. It was also hard to find out what caused the problem and to sort out the "risky" units while production so Freudenberg went a step down in there specs and millions where still on the road used by BMW making nearly nill trouble ( but maybe soon they will come ).
The distrubutorbelt is a similar story. Porsche had no falures as the parts never had enough time to age in the ozone. And also the first failures where delayed to the secound ownership when the people decided to save money and stretch the maintance. This leded to higher spark demand on the wide gaps and therfore the finger and cap burned up producing ozone. Also those people "couldnīt" afford to renew the caps and finger as they cost to much and the car also runs with the worn parts.
So both problems where hard to find in rapid testing and both elements where complete new in car world and therfore not enough long therm datas. Interesstingly both components are based on rubber and we all know that rubber will age. Porsche shurly was aware off that but didnīt thought the aging prozess will come so soon speeded up by random, heat and ozone.
Now I know 964 with more then 400000 km and still the first clutch including Freudenberg DMF and a retrofitet vent kit over the old rubber. As a mechanic my advise is allways to keep a godd maintance and drive as long as the parts will make no problem.
When the clutch is worn the cars get allways the update with the LUK DMF and the new TOB ( needing new guiding tube/fork ) as the old parts are not aviable anyhow. Could be that most Freudenberg DMF would have made a much larger lifespann but noone will bear the risk and I donīt like to work for free. Some costumers who are short on money or like to pocker still keep the old parts and still drive them. It is there choice.
On the distributor i usually exchange it with a upgraded one. That is the cheapest way fro a proffesional. But I also made the vent upgrade alone if the costumer wantet it.
From my own observation on a small basis I never had seen a failed belt. I had seen some at Bosch who informed there mechanics about typical first signs and how it can end in the worst. I also renewed sveral DMF but only two off them showed a failure. Both cars had a ultra low suspension and 18" wheels so maybe this is a better way to find a trouble car then looking on the odometer.
One couldnīt afford a new DMF and the upgrade and so whe "giftet" him a known old used DMF and this car is still driving, some 3 years later, around here. Still a happy costumer who loves his car andf one day will have the money to do the things right.
See Iīm not a Porsche mechanic focused on the cars. Iīm a mechanic on cars try to help the owners make there dream come true even if it isnīt perfect. Your local Porsche dealer maybe canīt do that.
One thing in germany is that most cars got upgraded as soon as possible and you will not find to much cars runing on the old parts.
Only very low milage garage queens have datet inerta and strangly some people pay more for a garage queen as for a complete updated wel driven in car who has only a 1 instead a nought on the 6th digit from the right.
Grüsse
