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YOUR RESEARCHHelp -- new belt seems too short
Reported or suspected cause
belt is cold and thick
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No successful repair reported for this finding.
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Reported cause
The other problem is the new belt is cold and thick.
Leading evidence: 'belt is cold and thick' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'belt is cold and thick' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check belt a couple times this weekend' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Reported cause
The cause is the tensioner bolt+nut are rotating and need to be tightened.
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Performed · outcome unconfirmed · Original poster
I have triple checked the routing and I don't get it.
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Performed · outcome unconfirmed · Original poster
i checked routing so many times that I started doubting every diagram and photo on the internet, even the photos I had taken prior to removal.
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Performed · outcome unconfirmed · Original poster
Since I was there I tried the Porsche belt again and nothing has changed, still too small.
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Performed · outcome unconfirmed
When i did this the tensioner pulley was touching the opposing idler pulley and it barely went on there, and i replaced the tensioner and a genuine Porsche belt
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I replaced the alternator and lower idler pulley (on the engine block) and went to put a new belt on the car (Porsche OEM 2115) and it will not fit. I have the tensioner pivoted all the way to the new idler and I still need 1/2"-1" of slack.
I the idler is the exact diameter of the original and I put the old alternator in, same problem. I measured the belt and it is roughly 2115mm so what gives? I have triple checked the routing and I don't get it.
Unfortunately the old belt is gone (though I did test it against the new one and it felt like it was the same size) -- any advice?
Thanks!
Nathan
I had the same issue when I did idler and tensioner pulleys and new belt. Checked part #s and routing but finally it went on there, think I put it over the tensioner pulley last. Also used a cheater bar on my ratchet to make it easier
I replaced mine last year and all I remember is that it was a *itch to get on by myself.....similar issue to what you are describing, but it went on. Eventually.
One problem to check on is the nut behind the tensioner pulley. It requires a thin 15mm wrench. Hope you do not need to use it - very difficult to locate/hold/position.
The problem will seem to be that you can not get full rotation of the tensioner pulley. You can't move it over quite far enough to get the new belt on. The cause is the tensioner bolt+nut are rotating and need to be tightened.
The other problem is the new belt is cold and thick. Try a warmed(not heated) Conti instead of a Gates ? I still have an unused Gates belt because I could not fit it. A slightly thinner, more flexible warm Conti slipped on with a bit of a struggle.
But before you do any of this check all the pulley bearings for wear - or you will have a redo.
While you are in there, stick your finger around the neck for the P/s fluid reservoir. The "O" rings crack/shrink and leak. Spin the w/p for wobbles/noise/drips.
Good advice.
I replaced mine a year ago ... it was a bear to get on. It really seemed too short. I pulled it off to compare to the old and they were the same. A couple months later I went through the same experience replacing the belt on a friend's car. They will go on. But you do have to bottom out the travel on the idler pulley.
When i did this the tensioner pulley was touching the opposing idler pulley and it barely went on there, and i replaced the tensioner and a genuine Porsche belt
Thank you for the hints and tips.
I left the belt on the dash of my other car in the sun until it was hot to the touch, definitely more flexible but no dice.
I am considering getting a 2135mm Contitech but hate not using the OEM part.
The old belt was tight but doable by myself, this is a whole different level of frustration. Our BMWs have never been this hard.
I tracked down a belt 20mm longer used in A few Mercedes and installation was expected, simple and easy. Honestly it is a no brained for anyone with tight OEM figment. The voltage meter reads 14v while running and everything else is normal. The Tensioner pulley has another inch of movement available and the system is not under pressure from a belt that was shoehorned on.
For anyone interested, the pet number is 002-993-09-96-M21
-N
This might be stupid question...but are you sure you are getting all the travel out of the pulley? I.e., do you have the wrench in the position that lets you move the pulley completely? When I was trying to put mine on awhile back I had issues for a bit then realized I had more travel if I positioned the wrench differently.
Not to be a jerk, but how sure are you that your belt routing was correct? I have put serpentine belts on cars before and been SURE I was doing it right, scratching my head as to why the belt was just a tad too short, only to realize the routing was wrong, and then suddenly it becomes real easy
The tensioner should have plenty of play to be able to easily work the belt on. Put it on all the ribbed pulleys first, and leave an idler pulley for last since it will slide over those easier.
Think thrice, measure twice!
Keep us posted on how this works ?
This is a common problem so if a very slightly longer belt fixes it - we all should know.Thanks to CourseCorrect for sharing his experience.
Note the 20mm longer belt suggested (2135mm) is only
1 % longer!
than the stock 2115mm belt.Is this length correct??
i checked routing so many times that I started doubting every diagram and photo on the internet, even the photos I had taken prior to removal.
An additional 20mm is all that was needed to make the job easy. Because of the routing around the tensioner pulley it changed the position of the tensionerr approximately 10mm, you would not think that it would make a difference by it was stark.
I plan on check the belt a couple times this weekend and then a few hundred miles later, I will report back if anything is ot of sorts.
I would prefer to use the OEM belt but not under so much pressure. If you have a similar problem, try the 2135mm belt.
Route the belt around everything except the pulley immediately next tension pulley. Release the tension as much as possible and slip the belt over that last pulley. Those tension pulley and the one next to it should touching or close to touching at full release.
i tried leaving the alternator, alternator idler, AC pulley and lower idler (next to the tensioner) each as the last step but it was short everywhere (which makes sense). That was with the ensioner pulley touching the idler, there was no more slack in the system.
I drove for about an hour yesterday so I will icheck the belt today and see how it looks.
i pulled the air box to see if everything was fine and it was. Since I was there I tried the Porsche belt again and nothing has changed, still too small. The Contitech works beautifully and is a snap to remove and install.
Did you check if the new idle pulley has the same size as the old one ? There are multiple versions of the pulley (auto vs stick, diff MY, etc) Is the old belt the oem size?
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