Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - MIdasDriver

My wife has an April 2011 Panda 1.2 Active that has done about 30,000 miles. At the end of November it was clearly suffering from an intermittent misfire, although nothing was showing on the warning lights. We took it to our local Fiat garage & they diagnosed a faulty coil pack. To Fiat's credit, they stumped all but £20 for the repair within an hour of the garage asking them. The spark plugs were also changed.

However, we were then told that the car was lumpy when idling as there was a spllt in a breather hose. This was changed last week ( I still think that £30 + VAT for a small bore breather + £40 fitting is taking the ...) and the car still isn't running quite right.

It still has a lumpy lide although it revs cleanly when in neutral. When it is driven, there is a definite hestation pretty much throughout the rev range, although i can't say that I have explored the upper end! It really doesn't seem like a misfire as there is no real jerkiness like a misfire gives. There is still nothing on the engine warning lights.

The garage has had another look and, i am told, apart from checking what they did previously have now carried out a cylinder leakage test, another test starting with con (can't read the writing) and have also swapped the coils & leads. They have checked all parameters and all seems to be OK.

They now want at least £300 to check the timing, injectors & wiring. Therefore, it seems to me that they haven't got a clue what the problem is and will resort to checking various things until they find something that is faulty, which could take days & cost thousands.

Any ideas of potential areas of concern so I can narrow the search down?

Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - Quicksilver

What kind of fuel do you use?

Does it get some long journeys?

Q.

Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - MIdasDriver

What kind of fuel do you use?

Does it get some long journeys?

Q.

Almost always standard Shell unleaded. Occasionally supermarket when there is an offer on.

It does do mostly shortish journeys, less than 20 miles, but it did a 300 mile round trip last month.

There now seems to be a petrol smell in the car as well, which is new.

Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - MIdasDriver

What kind of fuel do you use?

Does it get some long journeys?

Q.

Almost always standard Shell unleaded. Occasionally supermarket when there is an offer on.

It does do mostly shortish journeys, less than 20 miles, but it did a 300 mile round trip last month.

There now seems to be a petrol smell in the car as well, which is new.

My mistake - no petrol smell.

Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - skidpan

Forget the brand of petrol, all fuel sold meets the requirements of relevant BS and all cars only require fuel to relevant BS. Different brands have different additives but that is the only difference and there is absolutely no proof these additive (if they actually exist) make any difference.

I would suggest trying a different garage first.

Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - bazza

Back in the old days, this would most likely be a fuelling issue, and I'd be whipping out the plugs looking for weak or rich mixture, air leaks etc. but as Skidpan says you need to find a decent diagnostic garage, who can hook up some kit and analyse real time data etc. This 1.2 FIRE engine is one of the simplest straightforward engines still out there, so it shouldn't be that hard to put right.

Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - MIdasDriver

I've been told that they've hooked it up to the diagnostic machine & there are no error codes showing since they replaced the coil pack. The plugs were also replaced at the same time.

I think that a change of garage is probably a good starting point.

Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - Railroad.
This supermarket vs branded fuel debate has been done to death. All road fuel sold in the UK must meet BS EN 228 for unleaded and BS EN 590 for diesel. This is quoted on all filling station pumps. This is the standard by which fuel must comply, but it does not mean the end product is the same. The additives used for engine cleaning and performance differ from brand to brand.

Your problem may well be sticking valves which has been known on this engine. A manifold vacuum test would confirm this.
Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - Big John

Has it been fitted with an OEM replacement coil pack, there a few dodgy cheap replacements on the market. Also worth replacing the ignition leads as the position of the coil pack leaves them slightly vunerable (just behind radiator)

Might be worth trying the leads first though - I seal mine once a year

There a couple of things to think about after a coil pack replacement though

1) It is not unknown for a failing coil pack to HT spike what is feeding it - usually ECU. You would be running on two cylinders now if this had been the case

2) When a coil pack is failing unburnt fuel is sent down the exhaust - this can damage the catalyst which may (OR MAY NOT) cause problems at the next MOT - I had a coil pack fail on my Octavia a few years ago where I drove (suprisingly well ) about 15miles on two cylinders, On replacement all seemed well and it always passed its MOT but recentley when the catalyst rusted through due to old age the car ran much better and the MOT emmisions figures are now much better

Edited by Big John on 24/12/2014 at 23:06

Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - MIdasDriver

The coli pack was fitted by a Fiat dealer, so it had better be an OEM part!

I wouldn't have thought that the engine was running on two cylinders as I would have hopednthat the garage would have picked that up the second & third time that they had it.

I was told that the leads & the coli packs were swapped around & there was no change, but a new set of leads probably wouldn't hurt

Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - MIdasDriver

Sticking valves doesn't sound like a cheap fix!

Fiat Panda 1.2 Active - Lumpy idle & hesitation while driving - Railroad.

Sticking valves doesn't sound like a cheap fix!

A good old fashioned Italian tune up when the engine is at normal operating temperature often helps. Also you could try a dose of Cataclean in the fuel tank, or use Wynns Valve Treatment, available from Halfords and other good motor accessory stores, and also avoid using cheap supermarket fuel.

 

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