Sluggish transmission

I have lately acquired a 2000 P38 diesel, it's done a fair few miles but is generally very clean and was pleasingly inexpensive. It has behaved very well, both around town and on the motorway, but in the last few days has shown some inconsistent behaviour in the automatice gearbox. It is sometimes very reluctant to move up into top gear and one one occasion barely got out of second and over 30mph in a 10 mile journey. My immediate thoughts are an oil change or at least a level check and top up, does anyone have any experiences that might suggest this is a more fundamental, and expensive, problem?

Couple of oil changes and some Lucas should sort it sounds like sticky valve block. Have you checked the level?

Mine does similar in sub zero temps in Czech in that it won't lock up for about 5 miles until the oil gets warm but it still goes through the gears OK.
@wammers, do the temp sensors in the head not affect the gear changes too? I'm just wondering if it started doing it suddenly it could be a duff sensor.
I agree an oil change or two won't hurt but if it was the oil or sticky valves I would have thought it would be a fault that would slowly get worse rather than suddenly?

wammers said:

Couple of oil changes and some Lucas should sort it sounds like sticky valve block. Have you checked the level?

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I haven't checked the level yet, a little job for the weekend. I've got some Dexron III, I assume it will mix OK if the box is filled with IID? What Lucas do you mean, some sort of additive?

Dexron3 it is! Drop the sump plug, drain out and refill untill it starts to dribble out, then refit the level plug.
Idle the bus upto a nice hot temp and put the gearbox through the the gears manually. Then remove the level plug and top up untill it dribbles slowly again with the engine running in park on level ground.
Once done run it for a few days, then drop the oil, the sump and change the filter and refill it again with the above procedure.
A lot of oil stays in the torque converter and the second drop will help dilute the resting oil from the first oil drop. As wammbles says the Lucas additive helps to lube the small moving parts like the solenoids.

Wazzajnr said:

Mine does similar in sub zero temps in Czech in that it won't lock up for about 5 miles until the oil gets warm but it still goes through the gears OK.
@wammers, do the temp sensors in the head not affect the gear changes too? I'm just wondering if it started doing it suddenly it could be a duff sensor.
I agree an oil change or two won't hurt but if it was the oil or sticky valves I would have thought it would be a fault that would slowly get worse rather than suddenly?

Click to expand...

I've heard this temp issue before. A friend of mine has this problem on his jeep grand cherokee, when cold it doesn't like changing but when warm runs fine.
Only an issue in the cold weather.

Mine changes fine, it just doesn't lock up the torque converter and it only happens below 0 degrees C

This is the lucas stuff
http://www.ebay.co.uk/itm/LUCAS-OIL...012100&hash=item4b31f75505:g:G~MAAOSwi8xaQnZI