Technical Odd Twinair error.. Investigations

[varesecrazy]

Hi,

Background to a poorly twinair
(I've been on here a while, but don't post in the modern panda section often)

The Car: 2013 panda ta - euro 6

Purchased before Covid on 11k miles

Got supplying dealer to investigate a "Misfire" scenario when half-warm

No resolution.. Not shocked..
This is repeatable, and unchanged

If dash display shows 1 bar of temperature on startup,
Car starts perfectly.. But judders for
@ 300 metres, temp climbs to 2 bars.. All good

Done this for another 30k, plugs and Oils have made ZERO difference


BIGGER ISSUE:

At a specific point on a regular run...
It will misfire, lose power and throw an MIL (Dash warning)

Around 1 hour 30 into a trip

IT ONLY does this in warm weather.. All winter is fine


Now the twist...

Did the trip 2 weeks ago,
As anticipated.. 1h30m in it misfires.. Throws an MIL

Lacking in power, etc

BUT.. Whilst still doing 2500 rpm
There Is a chime and the OIL LIGHT is on..!

Appreciating that would "normally" mean that no oil is circulating..
I dip the clutch.. Vehicle is still rolling along at 50mph

Ticks over ok

So.. I turn it off

Wait a few seconds and restart

Oil light now OFF, and misfire less pronounced


Thoughts..?
Low Oil pressure = poor Uniair action

Sounds logical..

But How..??!!


Engine is at 50% of its max revs, oil SHOULD BE CIRCULATING

Maybe the Uniair has a sensor


Been out in the car today @60 miles.. All ok

These were found via MES

(Basic reader found ZERO errors)

Are these manufacturer specific...?

98 denoting OverTemp..??

 

[varesecrazy]

Some background from 10 months ago..

Odd twinair question | FIAT Panda (2012+)

Hi all, Brought about by recent events.. a question Your Digital Temp display.. Does it show COLD ..or tend to stick at '1 block' ? Backstory.. car seem to display '1 block' most of the time.. and if started in that state it will run poorly Pretty much 100% reliably This week on a...

www.fiatforum.com

 

[Panda IIs]

Some background from 10 months ago..

Odd twinair question | FIAT Panda (2012+)

Hi all, Brought about by recent events.. a question Your Digital Temp display.. Does it show COLD ..or tend to stick at '1 block' ? Backstory.. car seem to display '1 block' most of the time.. and if started in that state it will run poorly Pretty much 100% reliably This week on a...

www.fiatforum.com

I haven't had this specific experience with the TA, however, the symptoms remind me of a Golf I have that was a fussy starter (appeared to be ambient temperature related). I eventually tracked it down to a (water) temperature sensor, not for the gauge on the dash, but a separate one which adjusted the fuelling via the engine management.

While I acknowledge the recorded codes, these can be misleading - I'm pretty sure I have read your own posts pointing this out? Then of course there is the oil temp sensor that correlates oil viscosity to the UniAir control...

 

[varesecrazy]

I have recently acquired a 2nd Euro6 twinair..

So may start swapping parts now the weather is improving

Coils and other easily accesses parts 1st

Then if no changes, I will attempt coolant and Lambda sensors

One thing of note..
The exhaust has sooty marks below the manicat, and audibly blows when cold.. This Could explain the half-warm issue..?

 

[bugsymike]

You guys know more about these engines than me , but were they the ones where the oil pressure activated the valves etc. as in when they were stripped and rebuilt some had no compression due to not bleeding the air from the unit in top of engine. So if weak oil pressure to that area or incorrect oil type they gave loads of grief not activating the valves.
As you say "Thoughts..? Low Oil pressure = poor Uniair action" might be the direction I would test for.

 

[The Panda Nut]

A few thoughts
What plugs is it running? These new fangled fancy things are definitely different. Daughters Seat has (again) the proper ones per VW, with no less than 4 side electrodes to spark to. I tried running with some lesser plugs and it did not like it. It was just miserable.
If this were me, and allowing is has the right oil and I do mean the correct grade of petronas stuff I would change the temp sensor as I agree with Panda II's sentiments.

If you would like to suggest some some specific conditions to do comparrison live graphs I would be happy to plug in Noop and see what he shows for a base line. I would also check that Uni air filter, and change its sealing ring. Daffo when recently misbehaving (and previously) showed similar misfire error messages regarding misfires. That car then oveheated. Cleaning the throttle body and MAF and giving it new plugs, that I felt should not be needed restored that car to purring. I was very suspicious of the thermostat as I cant see why else it would have overheated. I wonder if there are fundamentla weaknesses to the Panda stats that affect 1.2 & 0,9 engines??

I also suspect that oil is not as consistent as its makers would like us to believe and wonder if your current fill is not quite what it should be. The big reason I stick with the specified Pertonas stuff. For the cost I think I would also change the temp sensor and stat if its the same unit.

It could of course be a thermostat thats just starting to fail sticking open at times and just being sticky until the temperature flips it from close to open. Off temperature readings suggests that side of things more than TA issues. TA malfunctionit seems to me is more likely to be low power or poor power delivery, or difficulty starting than misfiring. If a valve is failing to work I feel odd running of a different nature would be the order of the day rather than a misfire.

Maybe consider a compression test ?

 

[varesecrazy]

You won't get a reliable compression figure (Uniair..)

Oils have been changed with no difference,

As I say this 1.5 hour issue doesn't happen at 5 or 15 degrees, but it DOES when warm out

The 1 bar on temp gauge does

Need to work through the easily swapped parts.. If error moves cars that's the amswer

 

[Panda IIs]

You guys know more about these engines than me , but were they the ones where the oil pressure activated the valves etc. as in when they were stripped and rebuilt some had no compression due to not bleeding the air from the unit in top of engine. So if weak oil pressure to that area or incorrect oil type they gave loads of grief not activating the valves.
As you say "Thoughts..? Low Oil pressure = poor Uniair action" might be the direction I would test for.

Certainly missing on one cylinder was my experience of UniAir failure - this was at 45K miles (and no service history) Fiat dis however acknowledge this as being "early" and gave a "goodwill" discount on the parts. Here though the intermittent nature makes me think there is a sensor failing. @varesecrazy does it smell like it is overfuelling when the issue occurs??

 

[varesecrazy]

Certainly missing on one cylinder was my experience of UniAir failure - this was at 45K miles (and no service history) Fiat dis however acknowledge this as being "early" and gave a "goodwill" discount on the parts. Here though the intermittent nature makes me think there is a sensor failing. @varesecrazy does it smell like it is overfuelling when the issue occurs??

No obvious overfuelling..

But it does it at 60mph, so unlikely to smell it..

 

[varesecrazy]

Thanks for your detailed replies

The error code has only been reported on here twice

Once is a badly timed FIRE,
and once in a TA

So NOT pointing at Uniair failure

WILL update as I do more testing

 

[bugsymike]

Any chance of "data logging" when you anticipate next time of fault?

 

[varesecrazy]

Any chance of "data logging" when you anticipate next time of fault?

Quite possibly..

@Tropicalmike has posted some of his pandas diagnostics..
The faults codes look the same..
BUT the effect is different

The
P0300-98 generic misfire over temp
P0301-98 misfireover temperature
P0302-98 misfire over temp

 

[bugsymike]

Quite possibly..

@Tropicalmike has posted some of his pandas diagnostics..
The faults codes look the same..
BUT the effect is different

The
P0300-98 generic misfire over temp
P0301-98 misfireover temperature
P0302-98 misfire over temp

What seemed strange to me was with some where it appears that the Uni air system and oil pressure was related to the fault, some error codes mention ignition, so unless the ECU cuts ignition if no compression (or whatever happens when the oil pressure is wrong) or am I over thinking it?

 

[varesecrazy]

I was chasing the thought of
Misfire = Electrical

But the Oil Light coming on at 2500 rpm, made very little sense..

Could only conclude it was a loss of Uniair pressure..

As a switch off and restart restored normal service

 

[bugsymike]

I was chasing the thought of
Misfire = Electrical

But the Oil Light coming on at 2500 rpm, made very little sense..

Could only conclude it was a loss of Uniair pressure..

As a switch off and restart restored normal service

I am totally unfamiliar with these, but is there a oil pressure sensor on the Uniair side separate to normal engine oil pressure that you could get a reading from?

 

[varesecrazy]

I am totally unfamiliar with these, but is there a oil pressure sensor on the Uniair side separate to normal engine oil pressure that you could get a reading from?

I don't know,
but assume this Could be what triggered the light

(no error was stored for OIL..)

 

[varesecrazy]

Not going to make much progress for a week or so now..

 

[Tropicalmike]

I don't know,
but assume this Could be what triggered the light

(no error was stored for OIL..)

Hi guys,
I am not with my MES at the moment so cant check but I think there is only one pressure switch for oil in the engine. So if the light comes on probably = low oil pressure. The uniair doesnt work properly on low oil pressure and of course not so good for bearings etc . I am sure it is just a pressure switch and not a sensor so you or the ECU doesnt know an analogue value of the pressure that effects the control . I did see in Fiat e-learn in diagnostics about connecting a special pressure sensor in lieu of the switch. The uniair oil temperature sensor is the critical sensor for the ECU control of uniair valves. If your engine is overheating a bit and the oil gets too hot the viscosity drops and the oil pump wont work so well , and a dip in pressure occurs and the oil light comes on and uniair cant operate properly. I would suggest monitoring uniair oil temperature in MES at the time problems happen. Use the trend graphs including engine rpm.
BTW my twin air is in a 500 not a Panda but believe they are more or less the same. I think my uniair oil temp was 85 deg C for a fully warm engine. The oil cooler is just under the oil filter.

 

[Tropicalmike]

I'll make a note of my uniair oil temp and also engine temp and ambient when i have MES next connected.

 

[varesecrazy]

I'll make a note of my uniair oil temp and also engine temp and ambient when i have MES next connected.

In my MES errors the oil temp Said 85'c, so 'normal' to my eyes..

About to go out and cycle the 2 x Solenoids..

I've never tried before, got that tip from you

Not expecting to see any differences though.. As it runs great cold