possible problem with auto box ???

hi all,
hope the wise among you on here can mebbe's help me out with a problem on a 2001 2.5dhse auto, vehicle starts and drives fine , however wont go into top gear, ie at say 60mph its doing 4000rpm approx, anyhow spoke to a autobox fixer in glasgow and he reckons gearbox f**ked , where as me personally i dont think so as it drives sweet as, in auto or changing manually, just wont go into top
anyway gave into his more experience than me and gave him the vehicle to sort. he has had it two wks now and he has called me and said he is now not to sure that box is f**ked, he now thinks it could be a problem with engine/ signal from engine not telling box to change , 1 is this possible ?
2 i have taken another 2.5 dse upto him so he can compare signals / swap ecu etc,but another three days have went by and he has changed abs ecu ,gearbox ecu , and is still convinced its an engine fault , can anyone please throw any light on this , before anyone says have a diagnostic check done there is no fault codes on either engine or gearbox , when i first got vehicle battery was flat . so i bought new battery and fitted and reset all the usual windows sunroof etc, and put diagnostic machine on , and only fault in memory, was coolant temp sensor , i cleared this and restarted vehicle and it did not come back,so i took for test drive and thats when gearbox problem arose, sorry for such a long posting . however thought i best put down as much info as possible

thanks for your answers in advance jim

The engine will have no effect but the box speed sensor might although if it's changing through 1,2,3 OK that's unlikely. You sure it's not going into 4th and the torque convertor is failing to lock? Otherwise I would look at the output of the XYZ switch, do you get the correct gears on the message centre? Throttle position affects it too but if the engine performs OK that is also unlikely.

thanks datatek,
i will relay this info to the gearbox fixers , and see if that helps them

regards jim

I know yours is an oil burner but I had a hot start issue on the wife's '99 4.6 which resulted in me disconnecting the engine coolant temp sensor. With the ECT disconnected the car would over rev and would not go into 4th. Maybe worth looking at since you already the ECT fault..

thanks for that bit of info JT, i have already asked them to order new coolant temp sensor and fit it. to see if that helps also if nothing else it will have had a new one fitted lol

regards jim