Technical 2013 fiat 500 twin air with misfires under load

[walshawwilly]

hi newbie here so would like to say a quick hello,I have recently bought a 2013 fiat 500 twin air s which is misfiring under load and had a lumpy idle from cold,it has covered 45k and I fear it's services have been neglected as only 1 stamp in the service book and the oil level was very high when checked, which since has been drained and filled with the correct oil and level,I've fitted new iridium NGK spark plugs which seem to have made matters worse,my mechanic read the fault codes which came up with a misfire on number 2 cylinder, I fear the multi air actuator may be failing but obviously that's a costly job so just looking for anyone who has had the same problems or maybe personally changed the actuator, thanks in advance and any advice would be greatly recieved

 

[jrkitching]

hi newbie here so would like to say a quick hello

Hello and welcome to the forum :wave:.

Fitting Iridium plugs would have been my first suggestion; the second would be to check the coil packs (there have been some issues reported here; several early cars had them changed under warranty). If swapping the packs between cylinders also swaps the misfire, you've found the culprit.

Failing that, then yes, I'm afraid the uniair actuator has to be the next suspect.

If you do need one, you can buy it here for a more reasonable (though still expensive) price; if you make a donation to the forum, we'll give you a code to get a further 10% off that price.

 

[walshawwilly]

hi again, and thankyou for your warm welcome, update,it would appear that I was hasty with my first post,I fitted my spark plugs yesterday but when i started it,it was running really rough from cold but I didn't take it for a drive, anyway today I started it from cold and again it ran really rough at idle so I ran it at a fast idle until it had warmed a little and then took it for a spin ,the misfire/hesitation had gone completely and pulled cleanly in every gear under full load,it would appear I may have 2 separate problems,the car seemed to idle worse from cold with the new spark plugs but the weather is much colder than it was,I tried to remove the actuator filter this afternoon but I don't have a socket with a thin enough wall,will try and get one to clean this filter before I change the oil again,I'm now unsure as to wether to use the castrol 5w 40 I've purchased as I'm now seeing suggestions of using 0w 30 oil on these cars as an updated recommendation, at least now it's not misfiring under load which it was every time under full throttle,hopefully I won't need an actuator after all

 

[p6baseunit]

I'm now unsure as to wether to use the castrol 5w 40 I've purchased as I'm now seeing suggestions of using 0w 30 oil on these cars as an updated recommendation, at least now it's not misfiring under load which it was every time under full throttle,hopefully I won't need an actuator after all

So technically Euro 5 TwinAirs - 5w40 C3, Euro 6 Engines 0w30 C2
As far as I am aware nothing changed in the engine, so I assume it’s nothing more than about emissions - as the recommendation of oil for the Euro 5 engines haven’t altered.
Late 2013 is the change over year, there was a lot of confusion at the time.
I have a Dec 2013 TwinAir and was told by the service department at the suppling dealer to only ever use 5w40 C3 oil. The car has been given this oil every oil change (for me 7 - 8k miles) and has run very well right up to 46000miles. I realise that I was advised incorrectly, according to the book... but seemingly various dealers have there own take on what the recommend oil should be.
Anyhow, I have a stock of good quality 5w40 in my workshop and don’t feel the need to change now.
The important thing for this engine is clean oil (turbo, timing chain wear and actuator failure etc) so change it regularly and way before the scheduled 18k miles!

 

[wardpaa]

Assume you dont have an engine management light on whilst the engine is running ?
If you have FIAT ECUSCAN and an OBD interface it would be worth checking for any pending fault codes. Rough running when cold can be caused by a number of things but I would be checking coil packs, MAF sensor, O2 sensor (as the engine is not in closed loop when cold) and temperature sender as well as any cracked hoses that could cause a vacuum leak.

 

[jrkitching]

As far as I am aware nothing changed in the engine, so I assume it’s nothing more than about emissions - as the recommendation of oil for the Euro 5 engines haven’t altered.

Things aren't this simple in the case of the TA. We're not in Kansas anymore.

There is an extremely accurate oil temperature sensor in the system, and it is programmed to translate that temperature into an assumed oil viscosity based on the parameters of the oil for the specific engine type - the Euro 5 and Euro 6 programming is different.

Basically if you use a different grade of oil than the one that your particular engine has been designed for, it won't work properly and may cause damage. If you use the oil specified for a Euro6 engine in a Euro5 one, the temperature/viscosity translation tables in the car's software will be wrong. There are some who say the oil must for this engine be OEM Selenia, as there is no guarantee that other brands, even of the same specification, will have the same temperature/viscosity characteristics across the whole of the operating temperature range.

There's a link to a detailed description of the system, written by the folks who actually designed it, in this post.

@walshawwilly, from what you've posted so far, I think you'll find it an interesting read.

 

[walshawwilly]

hmmm very interesting reading,to quickly answer questions, before I fitted the spark plugs the car would hesitate /misfire under heavy load and if you persisted to push it the engine light would come on and go off again after restarting, I've had the codes read and cleared and fitted new iridium ngk spark plugs and upon starting still ran roughly until warm,but once warm had no hesitation or misfire, so maybe I've cured one issue, incidentally I changed the oil for some part tubs of 5w 40 I had but only to try and flush the engine through before draining and refilling, my car was registered in March 2013 so is it classed as euro 6 and needing 0w 30,I wonder if the change to a thinner oil is to combat problems with the uniair actuator,seems funny that the part is the same on earlier models,I'm gaining a better understanding of the system now

 

[p6baseunit]

Things aren't this simple in the case of the TA. We're not in Kansas anymore.

There is an extremely accurate oil temperature sensor in the system, and it is programmed to translate that temperature into an assumed oil viscosity based on the parameters of the oil for the specific engine type - the Euro 5 and Euro 6 programming is different.

Basically if you use a different grade of oil than the one that your particular engine has been designed for, it won't work properly and may cause damage. If you use the oil specified for a Euro6 engine in a Euro5 one, the temperature/viscosity translation tables in the car's software will be wrong. There are some who say the oil must for this engine be OEM Selenia, as there is no guarantee that other brands, even of the same specification, will have the same temperature/viscosity characteristics across the whole of the operating temperature

Yes I get all that, but the above relies on the oil service reset to have been triggered on the ECU so the system knows the age/mileage of the oil - not just the service indicator.
My TwinAir has been serviced by the local dealer or a specialist, do you think this was ever triggered?....
Also neither the dealer or specialist used either 0w30 or 5w40! I found the specialist easier to deal with as I could supply the oil and Fiat OEM parts to fit.
Supplying dealer recommended only 5w40, local dealer only used 0w40.... so I get what you say from a technical point of view.. but in reality no one sticks to this and it seems to make very little difference. Only the specialist warned me about the damaged caused by the extended oil services (18k), said he had seen a number of Alfas and Pandas with the TwinAir engine with stretched timing chains and failed turbos, due only to dirty oil.

 

[walshawwilly]

I have a far better understanding of this system for the valve operation now but I'm still unsure as to wether I have a euro 5 or euro 6 engine,I seem to be getting conflicting information from oil suppliers, mine is a March 2013 registered twin air s 85 I think,so how do I know wether its euro 5 or 6 to determine what oil I need,and is it possible to use a more readily available oil than salenia

 

[walshawwilly]

I have a far better understanding of this system for the valve operation now but I'm still unsure as to wether I have a euro 5 or euro 6 engine,I seem to be getting conflicting information from oil suppliers, mine is a March 2013 registered twin air s 85 I think,so how do I know wether its euro 5 or 6 to determine what oil I need,and is it possible to use a more readily available oil than selenia as long as it meets the correct specs

 

[p6baseunit]

The MultiECUscan software will tell you once connected. It’s a good idea to get this and the available leads (from Amazon) if you have a laptop handy and plan to be doing some servicing etc.
With the incorrect oil the actuator will play up causing the engine to run badly.
Can’t say though that your going to notice much of a difference between the 0w30 C2 and 5w40 C3. At 5 1/2 years old 45k miles with 1 oil change this engine probably just needs fresh oil!
On the basis that even the manufacturer is being optimistic with 18k oil changes, one service in 45k is extreme. I would just get on with it and stop worrying.

 

[p6baseunit]

You can also check here

https://www.hpi.co.uk/content/diesel-news-the-future-of-diesel/hpi-euro-emission-standards-checker/

 

[TrevC]

From what I read a while ago on another thread, it's certainly worth cleaning/replacing the uniair filter if you can get it out.
Another simple thing to try is running the car on superfuel, eg Shell V-Power. It may clean the injectors etc and improve running, but will take a few tankfuls to have any effect.

 

[Ralf S.]

I've no experience at all with Twinair.. but I'm guessing that the switch to 0W30 oil is for the most part intended to lower internal engine resistance. Less resistance means less pumping losses and therefore less fuel required in the same intake charge to drive the pistons round... ergo, less emissions.

If the Actuator doodah is the same part number in Euro VI as it was before, that would kind of prove that the thinner oil is not a "fix" for any problems it might have suffered; Fiat could much more easily have just revised the oil-change interval, e.g. to 10,000 miles rather than 18,000. Cleaner oil means more chance that the actuator would stay clean.

If it was my old beast, I'd chack the coils and HT leads, by swapping cylinders 1&2 and checking whether the problem moved to the other cylinder or stayed on the same one. Similarly, you may have a blocked/weedy injector although I've run several engines to three and four times that mileage and never had an injector problem (touches his boner) so this might be red herring. Any road up, stick some injector cleaner in the tank.. use something a bit more hard-core than RedEx (e.g. Cataclean). You want as much Acetone and Toluene in there as you can get (RedEx is just 5% of each).

If Actuators cause misfires then that's the main suspect if the electrics check out okay. Is there way to dismantle it and clean the b'jesus out of it, or is it wear that makes it misfire? I'd dismantle it and clean it if that's possible (how is it bolted together?). I can't believe it can wear to an extent where it doesn't work... there must be some spring or dibber-dobber in there that's just gummed up.

New one looks a bit dear.... so if you end up with a new one, learn to clean the filter and do it every oil change without fail. Also change the oil at 9,000 miles.. that'll be around once a year probably so probably less aggro' than buying a new MA unit every few years instead.

Ralf S.

 

[JasonPap]

From what i know from speaking to INA the unit is “not disassembleable” and there are OEM’s that use the unit with 0w20 oil.. so just the wrong oil should not be the culprit.. unless it is VERY wrong.. like using 10w60 trackday oil...

It could be the oil pump not providing enough pressure and flow rate to refill the chambers in the valve body. If you dont want to chenge the oil again maybe try putting a new filter in it.. it could be that the oil pressure in your engine is generally low due to excessive wear and that takes its tole on the oil pressure feeding the unit..

Definately try and clean that filter it says it has on the inlet but rule out the electrics first please!

The calibration for the uniair system has a correction for long term wear and oil viscosity in it, the inferred volumetric efficiency from the lambda sensor and MAP sensor tell the ecu how fast the valves are closing and hence what the internal leakage is.

So rule out the electrics first and reset the service light so it goes back to thinking it has new oil in it..

 

[Mercky]

I have a far better understanding of this system for the valve operation now but I'm still unsure as to wether I have a euro 5 or euro 6 engine,I seem to be getting conflicting information from oil suppliers, mine is a March 2013 registered twin air s 85 I think,so how do I know wether its euro 5 or 6 to determine what oil I need,and is it possible to use a more readily available oil than selenia as long as it meets the correct specs

March 2013 would be Euro5, Euro 6 officially arrived in Jan 2014, so presumably even 2013 late builds might be E6 too but I doubt March would be. Mine is Jan 2014 and E6, I found a ribbon label on the cable connected to the ECU which confirms that, have a look and see if yours has one too, either way I've been running 0W30 without issue from new

 

[walshawwilly]

hi just to clarify it is a euro 5 engine,who ever supplied that hpi emissions checker your a star and will remember that for future referenc,I do intend to change the oil again with some control magnatec 5w 40 even though I've just changed the oil,it was a mix of some part bottles of 5w 40 I put in just to flush the system through, I fully intended to change it again, I'm struggling with this bloody uniair filter,I cant find a socket with a thin enough wall to fit it,I want to clean this out before I put fresh oil and oil filter in first,anyone else changed this filter and maybe a link for a socket that fits,thanks everyone for your help,its still running rough from cold,but its perfect once warmed a little, it sounded rather fruity with the airbox off earlier, lots of turbo noises ha ha

 

[p6baseunit]

hi just to clarify it is a euro 5 engine,who ever supplied that hpi emissions checker your a star and will remember that for future referenc,I do intend to change the oil again with some control magnatec 5w 40 even though I've just changed the oil,it was a mix of some part bottles of 5w 40

That was me, no worries. It’s a two cylinder engine and even when new does run a little lumpy when cold, I would say slightly too rich for the first few hundred metres.. that seems normal for the TwinAir

 

[p6baseunit]

From what i know from speaking to INA the unit is “not disassembleable” and there are OEM’s that use the unit with 0w20 oil.. so just the wrong oil should not be the culprit.. unless it is VERY wrong.. like using 10w60 trackday oil...

It could be the oil pump not providing enough pressure and flow rate to refill the chambers in the valve body. If you dont want to chenge the oil again maybe try putting a new filter in it.. it could be that the oil pressure in your engine is generally low due to excessive wear and that takes its tole on the oil pressure feeding the unit..

The TwinAir engine and the specific actuator under discussion here is only used by the Fiat group. It is also well know that using oil outside of a 0w30 C2 or 5w40 C3 can make the unit run like a bag of ****! I suppose it depends what is poured in, but the engine is designed to only run with C2/C3 engine oil.
Neither is the ECU able to determine what oil viscosity has been added to the engine or how this has degraded, outside of a preset set of parameters from the last oil service reset.

 

[walshawwilly]

That was me, no worries. It’s a two cylinder engine and even when new does run a little lumpy when cold, I would say slightly too rich for the first few hundred metres.. that seems normal for the TwinAir

I started the car last night to warm it through to tackle that uniair filter and you can smell how rich it runs when cold,still need to.find a socket to fit the uniair filter then I can change the oil and filter and give it a good run