archstanton

My drivetrain goes through a resonance at ~2600-2900rpm. Happens in all gears, but the engine revs smoothly in neutral with or without the clutch engaged. Is this normal for these cars? My mechanic keeps telling me its running great but I'm not convinced!

Brian

Steve Weiner-Rennsport Systems

Do you feel a physical vibration in that rev range or is it an aural resonance?

archstanton

You feel the vibration

Steve Weiner-Rennsport Systems

80% of the time, its caused by wheel and/or tire issues. Once in awhile, brakes.

Other, more obscure causes are engine related or clutch problems. Damaged pressure plates or clutch discs can create the vibration you feel, however I'd do a power balance check to confirm that ALL cylinders are doing the same amount of work.

Vane

archstanton

Steve, Vane:
Thanksfor the responses. I'll start pulling the injector harness connections and look at the CV joints

Brian

sugarwood

I'd get all 4 tires rebalanced. Cheap way to rule out a common culprit.

n8kruger

My 1986 had this same resonance with the stock chip. It disappeared with an Autothority chip (back in the day...) and remains gone with the Steve Wong chip now. I am confident its the engine not the trans/wheels.

archstanton

Tires & clutch are new. In any case the vibration is related to engine speed, not vehicle speed, but is only apparent under load.

n8kruger: Thanks, that's very interesting. I think I'll call Steve about this.


Brian