300tdi Auto Disco RPM 'wobble'

[Steadydisco]

Gday all, 

New to the forum, thanks for having me. I have recently acquired a 98 300tdi Auto Discovery with 280k on the clock. All seems well bar the fact that between 1850 and 2000 rpm, accelerating just before a gear change  there is a wobble or a surge in the rpm and acceleration of the vehicle. I'm thinking its either the fuel or the auto trans itself? Wondering if anyone could shed any light on the matter. Id really like to sort this out; its the only drama in a great condition car. Thanks

[Snagger]

I had gentle oscillations at similar rpm on a 33Tdi RRC but manual transmission.  It was a worn injection pump.  However, it'd be worth draining and replenishing the transmission fluid twice and replacing the fuel filter before having the pump checked and refurbished.

[ThreeSheds]

4 minutes ago, Snagger said:

However, it'd be worth draining and replenishing the transmission fluid twice and replacing the fuel filter

I'd second that, but with the addition of the transmission oil filter too - I am thinking it maybe something related to the autobox...

[Snagger]

Good shout - the transmission filter in its sump is rarely serviced, and could be preventing the pump from developing proper pressure.

Another cause could be the governor on the back of the box needing stripping and cleaning out before refitting with new seals, but go for the cheap servicing jobs first!