Citroen C5 X7 2.2 HDI auto gearbox

[Repmojer]

Hi!

I have a 2014 C5X7 where I suspect that the torque converter has gone bad as I have power loss on acceleration from stand-still or low speeds, with a mechanical rumble every time it changes gear 1 through 3. No codes to be read. I did look at replacing just the torque converter, but there are none used available at reasonable prices and a new one is just way too much. Looking at used auto boxes (Mine should be the Aisin TF-80 AM6.), there are some with decently low mileage (120 000km ish) that aren't too bad price wise. I'm wondering though, how interchangeable are the gearboxes between the engines? I have found one that matches my model year and engine. There is, however, one that is nearby that is from a 2017 X7 but that has the 2.0L euro 6 diesel. How different are the gearboxes?

[mickthemaverick]

I would try giving it an ATF and filter change first, it can make a big difference to performance of both the torque converter and the gearbox.

[Repmojer]

I would try giving it an ATF and filter change first, it can make a big difference to performance of both the torque converter and the gearbox.

I forgot to mention that I've done the oil change 3 times with the correct oil (and according to the guides on this forum). It was working fine until a couple of months ago when I started noting power loss from standstill (dangerous when you aren't expecting it).
The current gearbox has about 180 000 km. Shouldn't be end of life, but I guess sometimes one is unlucky and perhaps the oil changes revealed a problem.

The car is drivable and all, just very annoying to not have the same power anymore.

[Paul-R]

Did you use a diagnostic machine to tell the gearbox ECU that new oil has been fitted?

[Repmojer]

Did you use a diagnostic machine to tell the gearbox ECU that new oil has been fitted?

Yup, every time. It has been shifting fine except for some cold days when the first shifts can be a bit drawn out and harsh. I could do another reset just to see if there are any changes in behaviour.

Edit: The problems started a couple of months after the last oil change. I had also done a road trip in Germany without any problems at all this summer (just after the last oil change).

[Repmojer]

Update:

Probably going to just buy a low milage (ish, 120k km) gearbox from a car exactly the same spec as mine and then do a bench drain and fill of the gearbox.

[Repmojer]

An update for anyone having same symtoms. I bought the gearbox but so many other things got in the way so never got round to fitting it. Had an epiphany in the middle of the night and decided to remove the EGR and clean the valve, cooler and pipe. Wasn't even that much soot or grime. Noticed that the valve would stay stuck half open a couple of times when I pushed the plunger. One good clean later and the car is like it was before, i.e. rapid. It basically went from sometimes dangerously sluggish from standstill and bit anemic when up to speed to what I remember it being when we bought it.

I never got any codes at all relating to this problem. It's also very interesting that I got shudders and rumble sounds when changing gears, mimicking what I read symtoms of a bad torque converter are. Must have been the engine struggling to deliver enough power / correct power to the transmission and messing with it.
What I never got was surging or slipping from the transmission, which always bothered me and was why I got the "epiphany". Anyway the lesson here is to not get hung up on one cause, even if many things are pointing toward it.
The gearbox was like €450 or something, so can likely get my money back from selling it seeing as breakers here in Sweden charge double that for one with more km on it.

[Paul-R]

Thank you for coming back to tell us what the problem really was.