Kick-down problems

[tim124]

W124 220TE auto, 1993: problem when accelerating, either from stationary or to overtake (kickdown), with 'D' selected, in standard range. Engine revs increase but the car slows down, as if brakes are being applied; then it suddenly 'clears' and accelerates. Shifting down to '3' seems to override the problem - accelerates without this 'braking' effect. Main dealer unable to diagnose and solve the problem. Help! Thanks.

 

[Xtractorfan]

Has the gearbox oil been changed recently, it is amazing the difference this can make to a sloppy box

 

[tim124]

The story continues...main dealer replaced the throttle actuator motor, spark plugs and some of the leads, which made things worse (engine was reluctant to start from cold, gear-box 'stuttering' more pronounced). Took it back and their diagnosis was 'needs a new gearbox' (over £2k, plus labour!!). However, found a specialist gearbox company, Hardy Engineering in Leatherhead (if anyone's interested), and their diagnosis, after test driving, was that the problem is nothing to do with the gearbox, but an ignition/revs limiter problem ('flat spots' occurring when the engine is subjected to sudden acceleration). The limiter issue arose because the revs were restricted to 4000 rpm when the engine was given full gas in neutral. Have now booked it into an independent garage for them to try to find the fault. Will let you know the results ASAP!

 

[kth286]

Are you saying that you feel your car should rev MORE than 4000 ??????????

If so, you are wrong.

In neutral there IS a rev limiter at around that speed.

BUT in drive there is no rev limit until the engine red line.