Little lamb said:

Hi I have a 67 plate, my problem was exactly as you described, it started when I was on 4000 miles. After several visits to the dealership, I had to threaten them with rejection of the car for them to get Fiat technical involved who diagnosed the uni air module. Im now driving with fingers crossed its cured the problem. Maybe its not an issue affecting older vehicles. Mines the 60th anniversary model and it was number 30 off the production line.

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How is it since the replacement??

Just collected the car today after 4 weeks away at Fiat!! Had to wait for the Uni Air Module to come from Italy. Seems to be OK but let's see what a weeks worth of driving it does... So was I unlucky or is this a fault that might become a common issue??? Thankfully £895 bill was covered by warranty.

Cjpinner said:

So was I unlucky or is this a fault that might become a common issue???

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I think the jury is still out on this one. There have been some other uniair failures reported, but so far it's been a trickle rather than a spate. Some have failed at low mileages, but there are also high mileage cars here that have been trouble free.

Similar units have proven to be troublesome in the past on some Alfa's but, as they say, past performance is not necessarily an indication of what might happen in the future.

So if you're thinking of owning a TA out of warranty, I guess you need to ask the Eastwood question:

Do I feel lucky?

Cjpinner said:

Had to wait for the Uni Air Module to come from Italy.

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Shop4Parts keep 'em on the shelf (discounted, and donated forum members get additional discounts), so presumably there's a steady demand for them. It's possible there's more than one type, so perhaps yours is a later version not commonly stocked in the UK?

Hi,

New twin air owner here. According to INA/Schaeffler (the developer of the UniAir system) - the oil viscosity must be known by the system to work out the control responses of the system, so there is an additional highly accurate temperature sensor - viscosity is then calculated from that temperature. The viscosity temperature relation is different from oil to oil (even with the same viscosity rating), so the correct function (and maybe the well-being) of the twin air engine relies on using the specified oil. In the best case the valve timings/lifts will be slightly of, in the worst case .....

Unfortunately that doesn't answer the original question, as it now depends on the multi air unit - temperature sensor - electronics combination, which oil a Franken-engine would need.

Can we assume that all this is known and therefore a Euro5 engine would receive matching replacements to keep the original oil spec requirement?

Best

T

P.S. google "Technology INA UniAir® System" to find the technology white papers from INA - not allowed to post URLs on the forum

My bad. MultiAir was developed by Fiat Powertrain Technologies, of course, and later licensed to INA/Schaeffler. Documentation is readily available from the latter and applies to the twin air Fiats.

Torsten S said:

According to INA/Schaeffler (the developer of the UniAir system) - the oil viscosity must be known by the system to work out the control responses of the system, so there is an additional highly accurate temperature sensor - viscosity is then calculated from that temperature. The viscosity temperature relation is different from oil to oil (even with the same viscosity rating), so the correct function (and maybe the well-being) of the twin air engine relies on using the specified oil.

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Thanks Torsten; I've posted a link to INA's technical documentation in this thread.

So to continue the speculation (and this is only speculation), they might have changed the software for the Euro 6 engines (when they changed the oil specs) to take account of the difference in viscosity, without making any mechanical changes to the uniair module. So even if the uniair units are the same, the oil requirements may be different.

And identical uniair modules fitted to two otherwise identical cars running different software may behave differently, even with the same oil. That would explain a lot of what's been posted previously.

This is a deep rabbit hole.

Hi,

That's what I'd say, yes.

So, my take on it is, that if the Fiat part number of the multiair module is the same between the Euro5 and Euro6 engines, then the difference is in the mapping (and maybe other parts of the engine (e.g. cam profiles). In that case it is a reasonable bet that the oil spec is unchanged from the original one for that engine.

If there are different part numbers, then the right multiair module for the engine is required to match thermohydraulics and mapping. Putting a euro6 module in a euro5 engine or vice versa may cause problems.

If the multiair module was changed without changing the part numbers then that would be a mess.

I guess it would need input from the colleagues in Torino to say more at this point.

I hope the OP's problems are resolved.

For the record, Just like him, I had exactly the same issues on my 2012 T/A Panda last year, immediately after changing the oil (correct spec but not selenia) and immediately after carrying out a required Uniair reset..

I have a rough idle to start, the drive 200m and the car starts to kangaroo and splutter!! Then lights up like a Christmas tree then goes into limp mode still spluttering. So I pull over turn off and leave for 1min start up and resets and drives OKish...

I eventually traced the issue to the No1 Lambda sensor though nothing on Multiecuscan indicated it was at fault. Disconnecting it made the problem disappear, as did its replacement. Comparatively cheaper than a new Uniair fortunately .

Same issue here: 60.000 Km, 5 yr old, replacement costs £1300. Always used the correct oil ...

And we all know now, that both MuliAir and TwinAir units have a small filter/strainer that needs to be changed now and then as well, although it's NOT in the official service schedule...

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Is this on purpose, so that they can charge for the replacement unit?