Decel rpm fluctuation
 

Ok, first question on the forum for me so please be gentle. :)

I did a search and found a few g'box shift issues, but nothing along the lines of what I've got.

When going down hill I lift off throttle completely and allow the trans to control the engine braking (where fuel use goes to zero). Instead of getting a consistent brake effect, I get a fluctuation where the engine rpms go up and down about 200rpm and I can feel the car surging slightly as the rpms fluctuate in time with the engine braking coming starting and finishing.

I note the car is 2003 D3, has 120,000km's (75,000miles) and shes not had an ATF change due to dealer refusing to (I'm about to read the thread about ATF changes.)

Firstly, does this make sense and any ideas?

And, how do I know if the g'box map has been updated?

I had the same problem with my 2003 D3 4.2 and I managed to fix it by checking and topping up the Transmission Fluid. My car had done 120,000 miles and as far as I could tell had never had the gearbox touched, so I followed the workshop guidelines and checked the fluid level and ended up adding almost a litre and a half of fluid. After this it was much smoother to change, but more importantly it fixed the problem I had with the revs fluctuating on over-run just as you describe.

Great, thanks for the info.

I'll look into it, is there somewhere that I can find the workshop guidelines that you refer to?

After reading some other posts about our trans, I thought it may have been the pedal switch or indeed a complete ATF change.

Cheers

Just had ZF check the box fully. All programs, valves, fluid etc all 100% perfect.

Back to the drawing board. :(

Any other ideas anyone?