Fiat/Peugeot/Citroen transmission defect

kelly58 · August 19, 2009

lennyhb - 2009-08-19 5:07 PM
colin - 2009-08-18 8:00 PM As I've stated before, It's my opinion the 2.3 6 speed would have a resonable top gear even if the overall gearing was reduced as I often forget to change up to 6th as 5th is in most cases a good cruising gear.
I did about 70 miles on motorway forgetting to change into 6th, fuel consumption went form 27/28 mpg down to 22mpg & I kept wondering why it was so noisy. 6th gear is not particularly high it's about right for the vehicle.

I did the same thing the other week as this is the 1st vehicle with 6 gears , so i have printed and laminated a small notice " ARE YOU IN 6th GEAR " and blue tacked it to the dash , I know its sad but it saves on fuel .

colin · August 19, 2009

I drove a Citreon 2.2 6 speed PVC for a week and only put it in 6th a couple of times, averaged 28mpg. A drop from 28 to 22mpg for not using 6th does not sound right at all, I would suggest a miscalc or other factors involved.

BillH · August 19, 2009

I have the 130 engine and change up into 5th at 40 and 6th at 45/50 at the flat. She'll pull from 40 if careful. I have managed to average over 28m.p.g all the time and have hit 31 m.p.g. on one slow run over 300 miles.

Rgds

Bill

AndyStothert · August 22, 2009

I've now heard from dozens of owners of both Fiat and Peugeot 6 speed vans who have had the full range of modfications done to their vans, and the results are quite consistent - a significant improvement, but a feeling that it isn't quite good enough. However it seems that most are now prepared to get on with things and see what happens in the future.

I sent a letter to Fiat pointing out to them that despite the improvement the vehicle still wasn't as it should be and asked whether they would consider extending the warranty because of the nature of the work they have carried out and the inconclusive results, but they refused flatly to consider this. What they did say was laughable really as they state that they will consider any further action on a 'goodwill' basis.

This after all the aggro trying to get them to do anything during the warranty.

Peugeot, who in the past haven't been exactly famous for their good customer support, are still considering the question of both further work on their vehicles to sort the problem out properly or extending some warranties.

lennyhb · August 22, 2009

colin - 2009-08-19 7:32 PM

I drove a Citreon 2.2 6 speed PVC for a week and only put it in 6th a couple of times, averaged 28mpg. A drop from 28 to 22mpg for not using 6th does not sound right at all, I would suggest a miscalc or other factors involved.

Changing down from 6th to 5th increases RPM by 20% on the 2.3 130bhp engine so a drop from 27/28 mpg to 22 mpg is to be expected.

Brian Kirby · August 22, 2009

lennyhb - 2009-08-22 10:44 AM
colin - 2009-08-19 7:32 PM I drove a Citreon 2.2 6 speed PVC for a week and only put it in 6th a couple of times, averaged 28mpg. A drop from 28 to 22mpg for not using 6th does not sound right at all, I would suggest a miscalc or other factors involved.
Changing down from 6th to 5th increases RPM by 20% on the 2.3 130bhp engine so a drop from 27/28 mpg to 22 mpg is to be expected.

Sorry, but I'm not so sure. It is not revs that govern the amount of fuel used, but a combination of overall efficiency, and the amount of work the engine is asked to do. Engine efficiencies naturally vary across their usable rev range, but modern computer controlled diesels have surprisingly wide power bands, and tend to be quite efficient in converting fuel into useful work over quite a wide range of RPM. Obviously there are still limits so, once outside that efficiency band, it is just as possible to use more fuel by "pushing" an engine in too high a gear, as it is to do so by running it a high revs in too low a gear.

Where my doubt arises is that the rise in consumption is so great due alone to running just one gear lower. You would surely have become acutely aware if the engine was revving its top off so, an increase from, say, 2,200 RPM to 2,640 RPM, with the same amount of work being done, should result in only a slight increase in real fuel consumption, mainly due to higher friction losses.

I think this is the little on board fuel consumption computer speaking and, from experience, they are quite hopelessly inaccurate. Ours tells all sorts of fanciful tales, but it only takes "snap shots". I record the fuel put in each time I fill up, and the mileage. Spread over several thousand miles, and several hundred litres, this gives the only truly accurate indication of real life consumption, and it never co-incides with what the computer says!

colin · August 22, 2009

lennyhb - 2009-08-22 10:44 AM

Changing down from 6th to 5th increases RPM by 20% on the 2.3 130bhp engine so a drop from 27/28 mpg to 22 mpg is to be expected.

According to Fiat, changing down from 6th to 5th increases revs by 15%, or to put it another way changing up from 5th to 6th decreases revs by 13%, would this decrease fuel consumption by 13%? very unlikely.

Looking at the figures for the 120 engine it may be that this decrease in fuel consumption would be achieved if running in 5th at 4000rpm compared to running in 6th, but is this possible in the real world? I think not. I would guess that a 5% decrease in fuel consumption would be the very best possible at certain fixed speeds, but this depends on the programming on the ECU, and of cause the overall consumption will be less affected.

lennyhb · August 22, 2009

Over a varied range of conditions I would totaly agree with you Brian.

At the time I did my run in 5th I was cruising steadily with cruise control on a motorway.

I was doing an indicated 70 mph , 62/63 actual speed (nice accurate Fiat speedo).

The first trip I did in the van I checked the fuel consumption the old fashion way over 2700 miles and recoded 28.2mpg the on-board computer read 27.8 mpg better than 2% accurate not bad at all.

Yesterday I checked the revs at an indicated 70mph 6th 2500, 5th 3000rpm.

Colin refers to the 2.2 120 engine I am talking about the 2.3 130 engine on the camper chassis, they do not fit the 120 to the special camper chassis (camper chassis only has options of 100, 130 & 160 bhp) so it may well have different gear ratios.

jhorsf · August 22, 2009

If your speedo is so far out then how can you rely on your mileage with the same instrument?This must also makes a mockery of your mpg figures

lennyhb · August 22, 2009

The speedo is out but you measure distance on the odometer which I have checked and it is spot on, just because one instrument is inaccurate it does not mean all the other instruments are.

kontiki · August 22, 2009

Speedometers are supposed to be accurate to +10% -0 so reading 63mph at 70mph is just about within spec. Not sure how accurate odometers are, this must vay with tyre wear anyway.

As to MPG I have a Renault automatic, when we were in Scotland with all the bends/hills & slow roads we were on, most of the time we were in 4th or 5th. Everytime I thought I could keep it in 6th gear it would drop down to 5th. Our mpg was around my normal average of 27mpg & sometimes 28mpg. It suprised me as we also had quite a few trips on single track roads where 4th gear ws only just possible. It showed me that the best economy isn't always the highest gear.

rupert123 · August 22, 2009

This thread is starting to drift into a lets discuss anything topic. It was about the Fiat transmission defect but no one has anything new to say, about time it was allowed a decent buriel.

mike 202 · August 23, 2009

Agree with Rupert, the thread is drifting, the basic problem is at Fiat's door but compounded by the converters. Andy has, quite correctly, asked Fiat to extend the vehicle warranty, BUT if the converters and the dealers say that there is NO problem then how about one or both of them giving a Warranty on the transmission side of the Fiat. Because as they have said " There is no problem !! " therefore they would NEVER have to pay out. They should put there money where their convincing (ha ha) mouths are.

Problem of letting the thread die is that owners/potential owners (new members to this site) will not have information re the defect. Saving just one person from making a decision they regret is worth while.

bobalobs · August 23, 2009

As an "on hold" Fiat purchaser I very much hope this and similar threads do not drift or die at a time when there could be developments in relation to the 2.3 litre 6 speed.We have been led to believe that production ceased for a period and that this chassis is now in short supply. Some say production may have started again and I also heard that fiat did not close production for the summer break presumably due to demand though my source was not specific as to which models are involved. So if this is the position what gear box is being fitted? The old box with the mods covered at length on this thread or a new design? A response from Fiat would help!

colin · August 23, 2009

rupert123 - 2009-08-22 11:55 PM

This thread is starting to drift into a lets discuss anything topic. It was about the Fiat transmission defect but no one has anything new to say, about time it was allowed a decent buriel.

Not at all, a point was made that changing tyres might help, and this has progressed from there, so mostly relavent to a problem that Fiat still seem unwilling to fix for some, viva la thread.

yeti · August 23, 2009