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Going to confront mechanic - what causes wicked engine vibration *only* at 4k rpm?

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Old 07-06-2008, 01:29 AM
  #16  
yellowline
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Originally Posted by ModdedEverything951S
By "speeds" are you taklkind MPH or RPM? If you're talking RPM, then that is not always true. I misaligned the BS on my car the first time I did a belt job and it was perfectly fine at idle. It only vibrated the car apart after you got above 2kish RPM
RPM.

I think my engine was slightly out of time when I first got the car...smoothness increased across the operating range with a re-timing. It wasn't like I eliminated one resonance at one engine speed. Worth looking into, though.

FWIW, my 83 did not have the U stamped into the sprockets, so they were replaced. It may not be unrealistic to assume that someone changed the sprockets on really early cars.
Old 07-06-2008, 02:46 AM
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Originally Posted by yellowline
FWIW, my 83 did not have the U stamped into the sprockets, so they were replaced. It may not be unrealistic to assume that someone changed the sprockets on really early cars.
Very true, altho I wonder why Porsche made the change in the first place. Made more sense and easier for those who don't pay attention when working on these cars...

Originally Posted by Porschephile 924
I dunno man, both of mine (i think) have the U. I know the 924 does... donno about the turbo.
My car didn't have the U's. I doubt yours does unless someone in the past changed them...but your car is a low mileage car so you'd probably have records of that at least.
Old 07-06-2008, 01:02 PM
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Ben951S
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I live in an apartment complex, so no real time or space, though I am almost ready to debut my backup car to DD status... ugh...

I am in the North Wales/Philadelphia/King of Prussia area... would love to find a fellow rennlister to look at it...
Old 07-08-2008, 10:41 AM
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Ben951S
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Zip 19454 or 07960


What would be the best way to get a fellow lister to help me out? I would pay them for their time, and drive to them.
Old 07-08-2008, 12:24 PM
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PM Sent
Old 07-08-2008, 12:55 PM
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Ben951S
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Very kind! Replied! =)
Old 07-08-2008, 01:59 PM
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This might help.
Old 07-08-2008, 02:09 PM
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^ Just don't pay attention to the U's ^
Old 07-08-2008, 02:20 PM
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^ Just don't pay attention to the U's ^
Good point Darwin. Just note the Os, the orientation of the notches, and the orientation of the keys and you can't go wrong. If you get these right, the BS gear covers basically take care of themselves since you will only be able to insert them one way (into the empty key slot).
Old 07-08-2008, 02:25 PM
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Ben951S
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I have a playdate on Thursday with a fellow lister. I don't want to bring my car back to said shop anymore... I'm probably fixing my door handles myself tonight... oy. =) But very very grateful for all the help.
Old 07-08-2008, 03:57 PM
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Originally Posted by phoenix_iii
I have a playdate on Thursday with a fellow lister. I don't want to bring my car back to said shop anymore... I'm probably fixing my door handles myself tonight... oy. =) But very very grateful for all the help.
No problem. These cars really aren't that beastly to work on.
Old 07-08-2008, 04:58 PM
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I am sure Thursday will be a very good day for me. =)

Right now the 944 is my DD and I sold my backup car (my supposed, DD). I have something else in the wings but I am driving it back on Saturday, then it needs inspection/registration...

Saturday = Oil, trans fluid, brake flush, rad support replacement, to name a few, on the replacement (and official) DD. Those are things I can do without too much trouble.
Old 07-11-2008, 10:32 AM
  #28  
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Lower Balance Shaft Pulley Was Not Installed Correctly By Dinardo Foreign Motors... Stay away!

Big props to RS Barn for the assist!

Found some other niggly things that have been addressed (a few more to do myself but they are easy (cap, rotor, air filter, wires, spark plugs, finish vacuum lines, and clean grounds), to start. =)
Old 07-11-2008, 01:47 PM
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Glad that you got the issue corrected! Did they mess anything else up or was that it?
Old 07-11-2008, 01:56 PM
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Missing/Broken bolts on the a/c compressor and ps pump due to the lower bs gear being on the wrong way. Kind of a not so fun side effect.


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