Notices
993 Forum 1995-1998
Sponsored by:
Sponsored by:

Misfire and CEL cleared w/ Porsche Belts

Thread Tools
 
Search this Thread
 
Old 02-13-2008 | 03:32 AM
  #16  
geolab's Avatar
geolab
Rennlist Member
 
Joined: May 2006
Posts: 3,045
Likes: 182
From: Paris
Default

23$ + $10 shipping on ebay, 60 euros at dealer, regards
Old 02-13-2008 | 09:18 AM
  #17  
jimbo3's Avatar
jimbo3
Rennlist Member
 
Joined: Oct 2005
Posts: 13,414
Likes: 741
Default

Originally Posted by Avenger6
Geolab -

What did the belt tension tester doohicky cost?
That's a "Kricket". $11 at Napa auto parts. They'll probably need to get it from their local warehouse for you as it's usually not stocked in the stores. There are two versions- the one you need is the least expensive one. (I don't recall the number offhand.) I just got one a couple of weeks ago.
Old 02-13-2008 | 09:43 AM
  #18  
geolab's Avatar
geolab
Rennlist Member
 
Joined: May 2006
Posts: 3,045
Likes: 182
From: Paris
Default

Originally Posted by jimbo3
That's a "Kricket". $11 at Napa auto parts. They'll probably need to get it from their local warehouse for you as it's usually not stocked in the stores. There are two versions- the one you need is the least expensive one. (I don't recall the number offhand.) I just got one a couple of weeks ago.
if it has the same scale, the price is excellent news, this is one should have items to all RnList
Old 07-29-2009 | 01:27 PM
  #19  
aracer's Avatar
aracer
Instructor
 
Joined: Aug 2002
Posts: 144
Likes: 0
Default

the crank sensor is on the flywheel.....how would the front pulley have anything to do with that?
Old 07-29-2009 | 01:50 PM
  #20  
TheOtherEric's Avatar
TheOtherEric
Rennlist Member
 
Joined: Nov 2002
Posts: 12,065
Likes: 36
From: Chicago
Default

Originally Posted by aracer
the crank sensor is on the flywheel.....how would the front pulley have anything to do with that?
An old thread, but I'll respond anyway....
I agree, that doesn't make sense to me either. Perhaps if the alternator belt is slipping, then the voltage fluctuations either screws up the spark or the ecu somehow. But I can't see how a slipping belt would affect the entire rotation of the ENGINE and thus the flywheel.
Old 07-29-2009 | 02:46 PM
  #21  
Avenger6's Avatar
Avenger6
Rennlist Member
 
Joined: Jun 2001
Posts: 1,064
Likes: 14
From: Phoenix, AZ
Default

As I understand it, the vibrations transmitted back through the crankshaft to the sensor are enough to make it think there is an engine misfire, which would set up similar vibrations. I don't think it has anything to do with any possible voltage fluctuations.
Old 07-29-2009 | 04:29 PM
  #22  
JasonAndreas's Avatar
JasonAndreas
Technical Guru
Rennlist Member

 
Joined: May 2002
Posts: 8,138
Likes: 112
From: USVI
Default

Originally Posted by TheOtherEric
But I can't see how a slipping belt would affect the entire rotation of the ENGINE and thus the flywheel.
Misfire Detection By Evaluating Crankshaft Speed--A Means to Comply With Obdii

Methods of On-Board Misfire Detection
Old 07-30-2009 | 12:27 AM
  #23  
Tour18's Avatar
Tour18
Banned
 
Joined: Sep 2003
Posts: 1,610
Likes: 1
From: Flower Mound, Texas
Default

Rennlist is the center of the Porsche universe. IMHO.
Old 07-31-2009 | 02:48 PM
  #24  
Laura's Avatar
Laura
Pro
 
Joined: Sep 2001
Posts: 698
Likes: 0
From: Lake Forest, CA
Default

Lay a Porsche factory belt next to a Continental belt that is supposedly interchangeable and you can see the differences. They may be small but it does seem to make a difference. Our shop is adamant about using only factory belts.
Old 08-01-2009 | 07:26 AM
  #25  
Sonic dB's Avatar
Sonic dB
Racer
 
Joined: Apr 2003
Posts: 487
Likes: 4
From: Los Angeles
Default

CEL can be caused by many things. My 97 had a "blowout" of the plastic shroud which covers above the fan area which immediately caused CEL. My mechanic said that the CEL was due to the valve guides, but I suspected it was not due to the fact that it came on when the shroud blew up....and this was proven correct once I cleared the CEL and replaced the shroud it went away for months.

It came back several months later....when I had an issue of a broken belt and bent pulley caused by a worn out fan bearing which went.....and required immediate replacement of belts over 100 miles from home. The out of town mechanic used non Porsche belts and fked up the repair (its a long story not worth getting in to at this point but it caused the second bearing to fail and massive fan and alternator failure within 2 weeks). After driving for a few days....the CEL came on and my mechanic (who is very good btw) and Hergershemires in OC said it was an issue that required at least a cleaning of the SAI ports and possibly a rebuild...

however, once I had the belts changed to Porsche with new alternator and bearing, correctly by my mechanic...and the codes reset...the CEL light went out and has been out for several months of heavy driving since then.

the moral of the story as I see it based on these experiences: dont let anyone tell you that CEL = immediate rebuild because it doesnt. This system is very sensitive and needs to be properly maintained.
Old 08-03-2009 | 11:13 AM
  #26  
aracer's Avatar
aracer
Instructor
 
Joined: Aug 2002
Posts: 144
Likes: 0
Question belt transmitting vibration?

WOW, this is one helofa thread>>>I have no choice but to now change belts to factory, however I still cannot grasp the true creation of the CEL misfire code; which, presumably is the result of the belt issue. JUST cannot justify causal issue. m
Old 08-03-2009 | 03:54 PM
  #27  
cabrio993's Avatar
cabrio993
Race Car
 
Joined: Feb 2005
Posts: 4,682
Likes: 10
From: Johns Creek, GA
Default

The problem with the Conti belts is not that they are lose, so this is not a belt tension or a complete slippage issue.

The problem with the Conti belts is that they are .5mm wider than the OEM's even though they are the same length. By being wider and of the same length, when they are at the correct tension, the cross section of the belt is not flat / even but they are rather "pinched" by the pulley.

Due to rotational force, as the engine reaches higher rpms, it flattens the cross section of the belt and by doing so, the 2 halves of the pulley lose grip with the sidewalls of the belt only temporarily until it grips it back rapidly once the tension is lose. This causes a "hic-up" effect on the crank and the crank sensor detects it as a misfire.

If the belt was just slipping due to being lose, it wouldn't throw a CEL, it is this rapid pinching and releasing of the belt due to the wrong width and cross section that it creates that causes the problem.

You can read more in my original post from a year ago.
https://rennlist.com/forums/993-foru...ighlight=belts
Old 06-07-2023 | 02:04 PM
  #28  
ElCid86's Avatar
ElCid86
Instructor
 
Joined: Jan 2020
Posts: 165
Likes: 57
From: VA (USA)
Default

Note to anyone doing the serpentine belt. Use a Porsche belt from the dealership. I bough an aftermarket belt Dayco belt from a local auto parts store and within a thousand miles developed misfire codes on all cylinders: P0300, P0301, P0302, P0303, P0304, P0305, and P0306. (yes it is hard to believe and harder to explain that a belt can cause misfires but there were several cases reported here and Planet-9 so I gave it a try and swapped to a Porsche dealer purchased belt. Misfires are gone and I have put close to 1000 miles on the new belt to include spirited fun runs, Auto-X and long highway drives.) I'm sure others have replaced with Dayco or Continental belts without issue, but it's not worth taking the chance on having to do it twice imho.



Quick Reply: Misfire and CEL cleared w/ Porsche Belts



All times are GMT -3. The time now is 11:36 PM.