General Fiat 500 Twin air - Judder in 2nd and 3rd gear?

[Tidygirl2001]

I’m hoping someone can help! We bought our daughter a Fiat 500 Twin Air it’s done 75,000 miles but is in great condition. However it is lumpy when accelerating in 2nd and 3rd gear and we can’t work out why! Have changed plugs and air filter, done an oil change and filter but issue is still present. Its not bad but its also not right - has anyone had similar and can point us in the right direction to sort the issue?

 

[jrkitching]

Hello and welcome to the forum.

Rough running issues on any higher mileage TA (>40k miles) could point to a wearing uniair module; to avoid a lot of repetition, follow the links in this post.

Since this is an expensive repair (the parts alone will set you back almost £1000), changing it isn't something to be done unless you're sure it's the cause of the problem.

I'd start by cleaning the small oil filter in the uniair module; some folks miss this when doing an oil change. If it's in obviously bad shape, replace it.

Also be sure that you used the correct oil when you changed it; TA's are notoriously fussy in this regard, and the right grade depends on the model year, as the specification changed during the production run.

Lumpy running on acceleration could also be an indication of a turbocharger fault.

Judder under certain load conditions could be the early signs of clutch/DMF failure - if you car is one of the ones with a DMF, that won' be cheap either.

 

[Tidygirl2001]

Thank you. Thankfully the car is still under warranty so will suggest the garage looks at these things x

 

[steveras57]

Thank you. Thankfully the car is still under warranty so will suggest the garage looks at these things x

Not to be a naysayer but get em to refund you and by a basic 1.2 instead!_ generally more simple and reliable overall!, twin airs are great cars when they are right! but often they are wrong and are usually expensive to put right when chasing faults! same as the duologic gearbox cars its debatable if fiat did the correct amount of R&D testing and when you add in poor or uninformed servicing as the cars get older then the issues become a financial cross to bare!. hope you get it sorted without to much hassle!.

 

[jrkitching]

Good advice from Steve.

You may have discovered the reason why the previous owner traded in the car.

Not to be a naysayer

Me neither, but

Thankfully the car is still under warranty

I wouldn't pin too much hope on this.

Be aware they might try to fob you off, tell you it's not serious, carry out some small tweak, basically, anything to get you through the warranty period.

The TA has three significantly more expensive potential issues than the 1.2; the uniair module, the turbocharger, and the dual mass flywheel (though some very early TA's didn't have the latter).

If you do get offered the opportunity to hand this car back, then personally I'd recommend you bite their hand off!

 

[Tidygirl2001]

It’s frustrating because the judder is only slight and other than that the car is fantastic! Thanks for the recommendations x

 

[jrkitching]

It’s frustrating because the judder is only slight and other than that the car is fantastic

That's exactly the time when a thinking person with knowledge of these cars would sell it.

 

[steveras57]

That's exactly the time when a thinking person with knowledge of these cars would sell it.

Agreed! Go in there and let them know you are not satisfied and want to reject the car as unsuitable! let them know you have had advice from knowledgeable people (us ).

If they insist on "fixing the problem" agree!- but let them know that you require a written guarantee that whatever they do has solved the problem PERMINANTLY and ask them if they are going to further guaranty there work (again in writing) if not!- then tell them that you definitively want to reject the vehicle ( bearing in mind that it may not actually be a deception on there sellers part that there is a problem) more the previous owner moving it on for the afore mentioned reasons!.
If you meet any resistance then politely mention that you will be taking legal advice! .
If all else fails and you do have to accept there "fix" then whilst its not the most moral suggestion id say move it on again yourself and be well rid of it! might cost you somewhat in financial terms but in my opinion at least not as much as chasing down the potential faults and problems you are LIKELY to experience if you was to keep the car!.
Perhaps we should do a guide on the potential pitfalls of purchasing a twin air or duo-logic car so possible buyers could sort of be fore-armed with knowledge of what can ( and often does go wrong) with these cars BEFORE making there purchase decision? but i suspect that human nature dictates that the majority of owners come here " after the event" looking for help rather than searching for info before hand so might be of limited value I guess!.

 

[Tropicalmike]

Hi, wondering how you are getting along with this fault?

As a 500 twin air owner I would suggest you try and pin down the the "lumpy " to a particular band of RPM if that is possible . Try and see if it the same in 4th or 5th . That would point to the DMF I believe. Most normal acceleration is in the 2000-3000 band .
I realise you are going back to the garage who sold it. But If you have access to a diagnostic tool ( preferably MultiECUscan -MES ) check if there are any intermittent fault codes to do with the engine combustion , this might point towards the beginning of a Uniair issue. Being a 2 cylinder engine if either spark plug is in poor condition it could show whilst accelerating . There are Forum members who have the MES tool and may assist you if nearby ( me included ) There is the members MES register

Also you could try putting your foot down hard driving when the engine is cold. The uniair is more likely to misbehave with cold oil in my experience . But if the "lumpy" was from bad combustion for a few seconds I think you would get a dashboard engine warning light. For the Turbo , if the engine is consuming excessive oil it could be the turbo on the way out. There is always some trace of oil from the turbo gets into the intercooler , dropping the air hose off the bottom of the intercooler would show if there was an excessive amount.

What the others have said and suggest about the twin air "risks" is quite true especially at 75000 M. If you want a simple reliable Fiat 500 for your daughter a 1.2 is the way to go. Unfortunately , in my opinion once you have driven a twin air driving a 1.2 is a bit lame but there is a premium to pay to maintain them even without a major technical issue.

 

[Tidygirl2001]

Hi, thanks for the post.

It has gone back to the garage now for repair or if they dont fix then a refund. Garage were very good and didn’t argue. Ive shared with them all possibilities mentioned above and asked them to check everything.

We have replaced plugs and given it an oil change and changed both oil filters and also the air filter. When removing the plugs they were quite sooty and was running rich.

Will let you know the outcome but thanks for the additional information. I am hopeful that they will fix the problem because as I said before the car is so clean and such a fun drive it will be a shame not to get it back.

 

[Tidygirl2001]

Just a final update - week 4 and garage have not fixed the issue! Are trying to tell me the judder is caused by the rev limiter cutting in which could be a valid answer except it’s juddering at other times too They say they have taken to 3 mechanics and all say nothing wrong but when we test drove with garage opener and I pointed out issue as ge was driving he had no words!!! In their defence they have now given us a full refund so we will be looking for a new Fiat 500, just this time we will only be looking at the models with a 1.2 engine!!! Thanks for all your help and next time I will do my research before buying!!! Lessons learnt!

 

[steveras57]

Just a final update - week 4 and garage have not fixed the issue! Are trying to tell me the judder is caused by the rev limiter cutting in which could be a valid answer except it’s juddering at other times too They say they have taken to 3 mechanics and all say nothing wrong but when we test drove with garage opener and I pointed out issue as ge was driving he had no words!!! In their defence they have now given us a full refund so we will be looking for a new Fiat 500, just this time we will only be looking at the models with a 1.2 engine!!! Thanks for all your help and next time I will do my research before buying!!! Lessons learnt!

At least you got a decent outcome that didn't cost you a load of money !-others have not been so fortunate! 1.2 reliability over twin-air excitement any day!

 

[jrkitching]

they have now given us a full refund

Good result.