noz
October 26, 2005 05:35 am
Hi bestbear,
Can you tell if the frequency of the yah-yah is related to road speed or engine speed? ie for the same road speed, does the frequency go up if you change down a gear?
The disappearance on overrun suggests CV joint or engine related.
If CV joint then find a big clear car park. Stop. Engage first gear and turn the wheel as far as it will go in one direction. Drive around in circles with the loud pedal pressed. Repeat in the opposite direction. The noise difference should tell you which one has gone. The loudest will be the outside wheel when turning. ie clockwise - nearside, anticlockwise - offside.
The engine noise could be related to engine mountings or exhaust. When pressing harder on the loud pedal the engine rocks further on the engine mountings. If a part of the engine is touching the chassis then the engine vibration will be transmitted through to the bodywork. Of course on overrun, the engine rocks back to its original forward position and further away from the chassis so the noise goes away. The same goes for the exhaust. It may be clear of the body when you look at it on the ramps but when the engine is loaded and rocks backwards then it might be enough for the exhaust to touch the chassis. Check for adequate clearance all around the exhaust and in particular the condition of the rubber mountings on the first box, they're prone to perishing.
Hope this helps.
Cheers
noz