Always use stock OEM Porsche belts!
04-23-2008, 01:25 PM
#1
Race Car
Thread Starter
Always use stock OEM Porsche belts!
I recently took my car to the shop to get my steering rack replaced after it started leaking last week.
Normally, I do my own oil changes and alternator/fan belt changes. But since the car was already there and needed new belts, I went ahead and asked to do them.
I picked up my car and about 10 miles later the CEL engine light came on. I was close to home so I drove it there. I scanned the ODBII port and it showed:
P0300: Random Cylinder misfires
P0301: Cylinder 1 misfire
P0302: Cyl 2...all the way to cylinder 6 (P0306)
I reset the light and took it for a drive, this time with scanner in hand. Sure enough, 10 minutes later, the CEL came back with the same codes. Repeated the procedure 2 more times to be sure that it wasn't just a fluke and the CEL would come back right on.
I checked the engine and noticed that instead of Porsche belts, the shop used Conti belts, they seemed to be the right size belts too with 993 part numbers!.
I searched here and found that many have had issues with CELs and non-Porche belts. (Is this a great place or what?)
Took the car back and we replaced the belts with OEM and the CEL disappeared.
They are also puzzled and told me that they have a customer that they did a complete 60K service that included the belts and he was having the same CEL pop-up. They changed everything from cables, distributor caps, spark plugs, etc to no avail. They did use the same Conti belts on his car. The last thing it crossed their minds was this could be caused by the belts. They are calling him today to get them replaced.
Lesson learned and moral of the story...ALWAYS USE OEM PORSCHE BELTS!
Normally, I do my own oil changes and alternator/fan belt changes. But since the car was already there and needed new belts, I went ahead and asked to do them.
I picked up my car and about 10 miles later the CEL engine light came on. I was close to home so I drove it there. I scanned the ODBII port and it showed:
P0300: Random Cylinder misfires
P0301: Cylinder 1 misfire
P0302: Cyl 2...all the way to cylinder 6 (P0306)
I reset the light and took it for a drive, this time with scanner in hand. Sure enough, 10 minutes later, the CEL came back with the same codes. Repeated the procedure 2 more times to be sure that it wasn't just a fluke and the CEL would come back right on.
I checked the engine and noticed that instead of Porsche belts, the shop used Conti belts, they seemed to be the right size belts too with 993 part numbers!.
I searched here and found that many have had issues with CELs and non-Porche belts. (Is this a great place or what?)
Took the car back and we replaced the belts with OEM and the CEL disappeared.
They are also puzzled and told me that they have a customer that they did a complete 60K service that included the belts and he was having the same CEL pop-up. They changed everything from cables, distributor caps, spark plugs, etc to no avail. They did use the same Conti belts on his car. The last thing it crossed their minds was this could be caused by the belts. They are calling him today to get them replaced.
Lesson learned and moral of the story...ALWAYS USE OEM PORSCHE BELTS!
04-23-2008, 01:36 PM
#3
Race Car
Thread Starter
1) Porsche belt Part number 999 192 343 50 has dimensions 9.5x760mm, the Conti that was on the car with same refernec number was 10x760mm ( .5mm wider)
2) Porsche belt Part number 999 192 338 50 has dimesions 9.5x766mm, the Conti that was on the car was 10x765mm ( .5mm wider & 1 mm shorter)
I think the fact that they are .5 mm wider, even though the difference is miniscule, is enough for the Conti belt to not go as deep into the alternator pulley as the Porsche belt, making the alternator spin somewhat slower and confusing the ECU causing the false misfires.
04-23-2008, 02:10 PM
#5
Addict
Rennlist Member
Rennlist Member
Yup, I had the same issue, throwing Misfire CELs, Jason Andreas said "Use factory belts", I was dubious, but he knows a lot, so I went with his advice and it fixed it.
Thanks Jason, and Rennlist in general
Thanks Jason, and Rennlist in general
04-23-2008, 02:18 PM
#7
Mine are the 10mm wide Conti's that the mechanic put on at the 45K check. I get a CEL for mis-fire on Cyl 4 every couple hundred miles. PITA, but I haven't gotten around to changing them, yet. Will wait on my planned Fall service weekend to change to new OEM belts. Might also install an RS pulley "while I'm in there"!!
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04-23-2008, 07:17 PM
#10
Rennlist Member
Right on! A 0.5 mm difference is quite a bit in the land of V-belts. Can you
imagine being the poor slob who had the distributor caps, cables, etc.
changed when it may have been just the belts?! Good grief, I'd be cursing
a blue streak...
imagine being the poor slob who had the distributor caps, cables, etc.
changed when it may have been just the belts?! Good grief, I'd be cursing
a blue streak...
04-23-2008, 07:36 PM
#11
Addict
Rennlist Member
Rennlist Member
04-23-2008, 08:04 PM
#12
Race Car
Thread Starter
Really... and these are not cheap, made in China, imitations either. These are Continentals made in Germany specifically for the car.
What surprises me even more is that the price difference on the OEM belt vs these is not that much in the grand scheme of things. So why even bother?
It makes me wonder how many people are out there using these and dealing with CEL's thinking that there is something wrong with their ignition system.
What surprises me even more is that the price difference on the OEM belt vs these is not that much in the grand scheme of things. So why even bother?
It makes me wonder how many people are out there using these and dealing with CEL's thinking that there is something wrong with their ignition system.
04-23-2008, 08:05 PM
#13
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I recently took my car to the shop to get my steering rack replaced after it started leaking last week.
Normally, I do my own oil changes and alternator/fan belt changes. But since the car was already there and needed new belts, I went ahead and asked to do them.
I picked up my car and about 10 miles later the CEL engine light came on. I was close to home so I drove it there. I scanned the ODBII port and it showed:
P0300: Random Cylinder misfires
P0301: Cylinder 1 misfire
P0302: Cyl 2...all the way to cylinder 6 (P0306)
I reset the light and took it for a drive, this time with scanner in hand. Sure enough, 10 minutes later, the CEL came back with the same codes. Repeated the procedure 2 more times to be sure that it wasn't just a fluke and the CEL would come back right on.
I checked the engine and noticed that instead of Porsche belts, the shop used Conti belts, they seemed to be the right size belts too with 993 part numbers!.
I searched here and found that many have had issues with CELs and non-Porche belts. (Is this a great place or what?)
Took the car back and we replaced the belts with OEM and the CEL disappeared.
They are also puzzled and told me that they have a customer that they did a complete 60K service that included the belts and he was having the same CEL pop-up. They changed everything from cables, distributor caps, spark plugs, etc to no avail. They did use the same Conti belts on his car. The last thing it crossed their minds was this could be caused by the belts. They are calling him today to get them replaced.
Lesson learned and moral of the story...ALWAYS USE OEM PORSCHE BELTS!
Normally, I do my own oil changes and alternator/fan belt changes. But since the car was already there and needed new belts, I went ahead and asked to do them.
I picked up my car and about 10 miles later the CEL engine light came on. I was close to home so I drove it there. I scanned the ODBII port and it showed:
P0300: Random Cylinder misfires
P0301: Cylinder 1 misfire
P0302: Cyl 2...all the way to cylinder 6 (P0306)
I reset the light and took it for a drive, this time with scanner in hand. Sure enough, 10 minutes later, the CEL came back with the same codes. Repeated the procedure 2 more times to be sure that it wasn't just a fluke and the CEL would come back right on.
I checked the engine and noticed that instead of Porsche belts, the shop used Conti belts, they seemed to be the right size belts too with 993 part numbers!.
I searched here and found that many have had issues with CELs and non-Porche belts. (Is this a great place or what?)
Took the car back and we replaced the belts with OEM and the CEL disappeared.
They are also puzzled and told me that they have a customer that they did a complete 60K service that included the belts and he was having the same CEL pop-up. They changed everything from cables, distributor caps, spark plugs, etc to no avail. They did use the same Conti belts on his car. The last thing it crossed their minds was this could be caused by the belts. They are calling him today to get them replaced.
Lesson learned and moral of the story...ALWAYS USE OEM PORSCHE BELTS!
04-23-2008, 08:43 PM
#15
Rennlist Member
So the pulley shims can't deal with the .5mm difference? Seems like if slipping was the issue the Conti belts would actually work if fitted properly.
Not that it matters I guess... the Porsche belts are pretty reasonably priced, at least via Sunset Imports. Still, very interesting!
Not that it matters I guess... the Porsche belts are pretty reasonably priced, at least via Sunset Imports. Still, very interesting!