Hi All,
I'm looking for some help in diagnosing/resolving an issue with my car (or at the very least establishing whether it is just a characteristic which cannot be changed).
The Car : 2010 R400 Dry Sumped Duratec SV, kit built (by me) with all standard Caterham parts. It has been mapped by the 2 Steve's at T'N'R.
The Symptoms : The engine seems to have noticeable vibration which pattern (above what I would consider the normal vibration from an engine in a Caterham) which varies with revs. At idle it's really quite a noticeable and uncomfortable teeth rattling experience. As you go up the rev range it becomes a much higher frequency "tizz" which can be felt through the steering wheel and chassis. Over a period of time I actually find that my hands start tingling with a slightly numb/pins & needles sensation. I've just come back from a 2,500 mile European tour yesterday and I can still feel some numbness in my right hand today because over long distances it becomes really quite irritating. It's definitely not from the rolling chassis, because if I dip the clutch at, say, 80mph where the vibration is quite strong, then it goes away completely and it can just feel the usual road vibration. Also I can feel the vibration with the car stationary in the garage. I've had a Caterham before (albeit a K series) so I like to thing I'm pretty familiar with the usual Caterham noises, feelings and vibrations.
Some Background : I don't remember having this vibration when the car was new, however it went back to Caterham after a 1000 miles to have the sump pan replaced because it was leaking. I can't be 100% sure, but I seem to recall it becoming noticeable after the car came back. I'm not sure what replacing the dry sump pan involves, but could the timing have been disturbed during that process? (I think that the timing sprocket isn't keyed?). Would that causes such symptoms? The car pulls and revs fine through the range.
I have carried out a spanner check to make sure that the engine and gearbox mounts are tight. Is there anything else that I can check?
Could it be a flywheel or clutch imbalance? Would there be any reason why this could have developed? I'd be grateful for any help, suggestions or input from people experienced with this engine or people with a similar car with the same or differing experiences.
The car runs well in every other respect, but this vibration is making long distance drives quite uncomfortable and is starting to spoil the driving experience for me. I'd really like to understand the problem and see if there is anything which can be done.
Cheers for any and all input,
Mark
Edited by - spiderlane on 1 Sep 2011 12:31:56