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

[phoenix_iii]

I had my 944 brought to a foreign car place for timing belt and water pump work right when I got it, and a bunch of other small things. I had not had the car long enough (was a driveway rescue) to play with it beforehand (I knew it needed tbelt done).

Anyway, the car seems fine, except that at 4000-41000 rpm, I get a bad engine vibration, you can really feel it through the shifter, and with the hood up, you can see it in the engine it seems, and the engine doesn't even sound good. Does not make a difference if the car is parked in the drive way, clutch in, clutch out, etc.

The mechanic said the transmission is going, and to not worry about it, and take care of it when the clutch goes. Car pulls/feels fine, and I can blow past that RPM in 2nd without much trouble, no misses/trouble, but I feel that vibration.

Would this be synonymous with the balance shaft (or one of the pullys, I am not too familiar with the whole system) being mis-installed (backwards, I think I read or off 180 degress?). I also have had the motor mounts changed out already to the turbo mounts, no change.

Input is welcome. I had them install new door handles (After they lost one of mine saying I never brought it it, only to return it weeks later thinking it was the one they knew they had... wth.). It's due for a timing belt re-tension, and the fix they did on the door handles broke (they reused the darn roll pins instead of using a bolt like I told them to). Ugh.

Help? =)

[bud9344]

Balance shaft belt out off time. I drove my car (86 944 N/A0 all the home from Orlando with a broken balance belt. I think I was lucky the balance belt didn't fall in the path off the main timing belt. The trans is in the rear off the car. I f you have trans problem would you more likely feel it on the rear off the car.

-----------------------------
Bud

87 930 Black
86 951 Black
86 944 N/A Red (part car now)
87 944 S White
83 944 N/A Black
83 944 N/A White Auto

[moorepower]

Lower balance shaft mis-timed, most likely. It's easy to install the lower shaft sprocket 180 degrees out if you're not very familiar with these cars. There's a procedure on www.clarks-garage.com for checking the orientation of the balance sprockets without disassembling everything.

[petrolhead611]

sounds like what I had, although mine maybe jumped a tooth after first use having not being used for a year.Be careful, 'cos oil filter worked loose, and power steering pump bolts also became loose.

[phoenix_iii]

Found the procedure here. -> http://www.clarks-garage.com/shop-manual/eng-08.htm

What would be the best way to get a fellow Pelican to help me?


I am at location 19454 or 07960

I would pay for their time, and drive the car to them.

[phoenix_iii]

A person from RS Barn (on Rennlist) volunteered.

UPSIDE DOWN LOWER BALANCE PULLEY...


Engine is fantastic now. Fixed some other found issues as well. =)