4HP20 2.2 C5

[cachaciero]

This may not be just a 2.2 problem, as I understand it the ECU on the 4HP20 is the same ECU on the 2.0 ltr AL4 albeit with slightly different software. So it would seem to me that a high spec 2.0 ltr with ESP could well suffer the same problem.

cachaciero

[Pug]

First of all, sorry to revive an ancient thread but it helped me tremendously.

A little background: I have a 2005 Citroen C5 2.2 HDi 133 Automatic (4HP20) that has served me very well for almost seven years now, clocked up 240.000 km couple a weeks ago so I figured that I'll get another 100K clocked up before any major gearbox troubles. I had to buy a new set of winter tyres last winter so in hope to save a little bit of money, this spring when I had to buy also new summer tyres, I bought 205/55R16 tyres instead of the 215/55R16 that I should have (the price difference was about 200 euros for the set so it was quite significant - almost 50% more for 215/55 than 205/55).

(At least here in Finland) we can change the diameter of tyres max 5% without having to go to get inspection for approval so ~2% difference was ok and resulted about 2-3 km/h difference to the speed shown in the speedo. As you probably know, the spare in this C5 is the original Michelin Primacy 215/55R16 so I ended up in situation where the spare was actually bigger than the tyres under the car.

I blew my right rear tyre last week and changed the spare to it's place and then started experiencing exactly the same behaviour as described in this thread - the gearbox worked just fine otherwise but didn't automatically go from second to third gear. All other transitions worked just fine, upshifting 2 -> 3 manually worked and downshifting (automatic or manual) worked like a charm too.

Today I got the broken tyre replaced and got the spare off from the car and now the gearbox works just as before, no problems what so ever. So the 2% difference in tyre diameter on rear axle is in fact enough to mess up the ECUs and cause this behaviour with automatic gearbox. I had some bad luck with the tyres earlier this summer too and drove couple of days with the spare on front axle but the size mismatch didn't cause any problems there.

I think that it goes without saying that I'm very, very relieved because I was already mentally preparing to have to pay about 3000-4000 euros for getting the gearbox replaced with a rebuilt one.

Replacing or rebuilding the old gearbox was the only suggestion from a local specialist that most non-dealership garages use - I got the impression that they weren't even slightly interested of finding out what could be the problem, they just said that the turbine has probably failed and rebuilding would be the way to go. I also sourced a place from where I could get a rebuilt one with 6mo warranty for 2400 euros (plus work of course) and some boxes from dismantled cars in their original condition from a bit under 2k so there were some other options too - however I'm planning to keep this car as long as I can (the use-value for me is way more than the exchange-value in any case) so if I need to get some work done to the gearbox, I'd want it to be long-lasting solution.

[Ben82]

HI Pug, Welcome to the forum.

Glad to hear your problem had a simple fix.

Have you done an Oil Change on the gearbox? If not, with 240000km on the clock you're in the middle of when they usually fail, so would be worth doing a change to try to help extend it's life.
I have the process for doing it over here: http://www.frenchcarforum.co.uk/forum/v ... 01#p379390" onclick="window.open(this.href);return false;

[Pug]

No records of gearbox oil changes that I could find but after this ordeal and researching thereof I'm definitely going to have it done (I don't have facilities nor time myself).

I already talked to my regular garage this morning about it when I went to find out what the service program's gearbox oil inspection (every 60.000 or 80.000 kms IIRC) includes - nothing more than the oil level checking, it seems.

[Ben82]

You might want to import the oil from the UK, not sure what they cost in Finland, but I know here in Sweden it's about 205SEK per 1l bottle (~24 euros so about 120 euros in total). Whereas you can get it from opie oils in the UK, they often do 20% discounts at the end of the month, so each bottle is £8.39, and delivery is £18, so £59.95 delivered (~71 euros).

[Pug]

Nice, that's good to know! Thanks, Ben.

I was quoted 180 euros total for the gearbox oil change - didn't ask how the price is divided between oil and work. The official dealership charges 400+ euros for the same, according to local forums here.

EDIT: I looked around and actually I can get the same oil for about 16e per litre (80 euros for 5 litres) from several stores here so I would think that the independent garage I use wouldn't rip me off with that. Also waiting until the end of the month just to save about 9 euros by ordering from opie and still wait for their delivery would pretty much defeat the purpose.