Hi all!

Lately I've run into a problem with my 2007 Fabia (~130.000km) HTP.

During highway driving I experienced a sudden power loss and blinking check-engine light. When I stopped, the engine had a tough time idling, close to stalling. However, after reignition the problem appeared gone. I got the car to the garage, where they gave me new spark plugs, saying they were old (which was true, but I already had a feeling that could not be it...).

Then yesterday, again during highway driving (first time after said service), the problem again came up during overtaking. I managed to get home, but really at a snail's pace. I felt the engine was having trouble keeping power, even overcoming wind resistance. I several times had to reignite to get the engine back to "normal", although the situation increasingly got worse. Then finally, close to home, the check-engine light would stay on indefinitely, not blinking any more. Also, the engine would not achieve a "normal" idle after reignition, but be erratic.

Anybody an idea what this could be? The problem only pops up under "stressful"  conditions, e.g., overtaking on the highway while running the AC.

I do not have the impression this is anything mechanical with the engine, but rather a sensor/ECM/electrical malfunction. There are no weird noises, and after the service where they changed the spark plugs, during city driving and short highway distances, nothing appears/feels problematic.

Tomorrow I plan on bringing it again to the service, but would be nice to get some opinions from the folks here.

Thanks a lot!

Scan for the fault code(s).

Probably one ignition coil failing.

 

Thank you Wino, I'll mention this possibility to the garage. I'm not able to scan codes myself unfortunately. It surely seems something electrical. 

19 minutes ago, wgerven said:

I'll mention this possibility to the garage

 

Better to let them read the fault code(s) first, and tell you what they are and what they think will solve it.   

 

Thank you that's a good suggestion. I didn't ask for actual fault codes the last time, so maybe I should be more assertive about it

Almost certainly misfiring, flickering CEL then latching on really confirms it, hence the spark plug change last time, this time you'll need coil packs for sure which should cure it.

Thanks sepulchrave, that would be nice if it's so simple. What do you think, could there be damage to the catalyst by continuing to drive with unburnt fuel? When I mentioned it to the garage they didn't think it a problem, but I did read about it. 

22 minutes ago, wgerven said:

Thanks sepulchrave, that would be nice if it's so simple. What do you think, could there be damage to the catalyst by continuing to drive with unburnt fuel? When I mentioned it to the garage they didn't think it a problem, but I did read about it. 

 

No cat damage, ECU shuts down the injector on the misfiring cylinder when it latches the CEL, that's the hideous loss of power you're experiencing.

I have experienced the same after a car wash, I have opened the bonnet to direct sunlight so it dries any water , working fine since then

@sepulchraveAh ok, that clears something up then. Indeed, cannot even keep up against wind resistance. 

Edited 23 May, 20215 yr by wgerven

1 minute ago, wgerven said:

Ah ok, that clears something up then. Indeed, cannot even keep up against wind resistance. 

 

Just get the garage to replace the coil pack on the misfiring cylinder and keep an eye on your spark plugs next time, allowing them to wear out is what's killed that coil pack.

46 minutes ago, Taimour said:

I have experienced the same after a car wash, I have opened the bonnet to direct sunlight so it dries any water , working fine since then

 

Hi Taimour, well, I don't think it's anything water related, it happened twice after about 30min of highway driving with around 30C outside. 

10 minutes ago, wgerven said:

 

Hi Taimour, well, I don't think it's anything water related, it happened twice after about 30min of highway driving with around 30C outside. 

can happen with high humidity, anyways hope you will find the reason behind it soon

Is it the 6-valve HTP where the spark plugs and coils stick out forwards? Or 12-valve where they are central/vertical in the head?

2 minutes ago, Wino said:

Is it the 6-valve HTP where the spark plugs and coils stick out forwards? Or 12-valve where they are central/vertical in the head?

12V

Hi all,

Just an update: Today got the car back from service. Indeed cylinder 2 was misfiring. We discussed the symptoms, and indeed they agreed that it is most likely a problem with the ignition coils. So we changed them, and I hope this should resolve now everything. In any case, I'm not sure if this was just placebo, but it really felt in general the engine was more responsive and smooth with a bit more capacity than I was used to before the problems started.

Thanks all for the quality feedback!

Willem

Sounds like you got it sorted I was about to chime in and say it was a coil pack