Technical Jerkiness on light throttle, esp when cold.

[PacoJones]

I'm experiencing jerkiness on very light throttle when the car (2007 1.2 Dynamic) is cold (also once warm but much reduced). It happens on the transition between being off-throttle and slightly on-throttle, as you gently feed fuel in to maintain speed after backing off to slow down for a low speed corner, for example

I understand this is a known "characteristic" as mentioned in this thread: https://www.fiatforum.com/threads/cold-jerky-engine.437737/

The car was serviced by a FIAT specialist in Jan.

I changed the plugs in May and that fixed the issue, but it has returned in the last week or two. The car has only done a couple of thousand miles maximum since changing the plugs and has only done 28000 miles since new.

The plugs I used were NGK DCPR7E-N-10. Is it worth changing them to NGK DCPR7EIX iridium plugs as per the thread I linked to above?

Anything else that's worth trying?

Thanks in advance.

 

[jrkitching]

The plugs I used were NGK DCPR7E-N-10. Is it worth changing them to NGK DCPR7EIX iridium plugs as per the thread I linked to above

No harm in trying, and you'll most likely never have to look at the plugs again if you do. That said, 2000 miles isn't long, even for basic plugs like the DCPR7E-N-10. Depending on where you bought them, just maybe they weren't genuine?

The fact that changing the plugs before improved matters suggests it's an ignition issue, and given the age of your car, I'd wonder about the condition of the coil packs and plug leads. That's still not enough reason to buy new ones on a hunch, though.

Everything will be slightly worn on a 17 yr old engine; it's possible that the improved sparking performance of the DCPR7EIX will help mitigate this. And since they run with a smaller gap (0.8 instead of 1.0), the coil packs and leads won't be so stressed, either.

 

[PacoJones]

Depending on where you bought them, just maybe they weren't genuine?

They were from Euro Car Parts so should be the real thing.

I'd also wondered about plug leads but will start with iridium plugs and see how that goes. Thanks!

 

[jrkitching]

will start with iridium plugs and see how that goes

That's what I'd do too.

I'd also wondered about plug leads

Try running the engine with the bonnet up in the dark, and look for stray sparks.

Look, but don't touch; there are lots of ways a running engine can bite you.

 

[koalar]

NGK DCPR7E-N-10

Are good for 12000 miles and can be pushed to 20K

It not a known "characteristic" it means there is something wrong

I have had 3x 05 1.2, 06 1.1 and 10 1.2 none have done this when they are running correctly

Accelerator pedal is quite a common cause, but that would not be effected by changing the plugs

Probable worth checking the breather hoses aren't blocked as these get disturbed when you take the airbox off to change the plugs


The fact it clears up after it warmed up, probably means the plugs and coils are fine, they are normally worse when the engine is hot


I'd start by pulling the MAP sensor out and posting a photo of the tip, there's no need to disconnect the electrical connector, just remove the one torx bolt

I suspect it will be swimming in oil, and as the car warms up it evaporate off and condenses again as it cools, at this stage it's just a guess

 

[PacoJones]

NGK DCPR7E-N-10

Are good for 12000 miles and can be pushed to 20K

Yes, I was somewhat surprised the issue reappeared after only fitting the plugs such a short time ago.

I'd start by pulling the MAP sensor out and posting a photo of the tip

I will do so when it stops raining.

 

[PacoJones]

I'd start by pulling the MAP sensor out and posting a photo of the tip

Rain has stopped so here are a few pics - it's definitely a bit oily.

 

[PacoJones]

Sprayed the sensor with isopropyl alcohol and let it dry, then tried the car again and it's basically as good as new.

Would the sensor be oiled up for a reason, or just from the passage of time?

Any other steps I should take to keep the sensor cleaner in future?

 

[Pugglt Auld Jock]

Sprayed the sensor with isopropyl alcohol and let it dry, then tried the car again and it's basically as good as new.

Would the sensor be oiled up for a reason, or just from the passage of time?

Any other steps I should take to keep the sensor cleaner in future?

I've only just come across this thread and I was going to suggest cleaning the MAP too. I was surprised at the slight but noticeable improvement in smoothness of running when I cleaned mine - 2010 1.2 eco dynamic Panda. I now remove and check it at the yearly service.

Most likely nothing wrong with the engine, it's just oil mist from the breather - some have tried catch cans but i'm not sure how successful they've been

 

[PacoJones]

some have tried catch cans

That seems like overkill, I can happily remove the MAP sensor and clean it occasionally instead, it's only needed doing once in 17 years so far

It was one of your posts elsewhere about cleaning the MAP sensor that made me try cleaning it, so thank you!

Thanks to @koalar as well for suggesting looking at the MAP sensor in the first place.

 

[The Panda Nut]

I would also remove the throttle body and clean out any oil in the inlet manifold. We have one that needed this regularly. A clean throttle body seems to me to make a difference.

 

[koalar]

Sprayed the sensor with isopropyl alcohol and let it dry, then tried the car again and it's basically as good as new.

Would the sensor be oiled up for a reason, or just from the passage of time?

Any other steps I should take to keep the sensor cleaner in future?

Yes

There's are many causes

Blowby gasses are controlled by vacuum

And should enter above or below the throttle body butterfly

Unless the system is sealed, and no pipes are block the grass flows too slow and slowly fills up the inlet manifold

Engines with the electronic throttle body, MAP on the drivers side (RHD) Here the sensor is at the end of a long channel that can fill up with several CC of oil are worse effected

The two main causes are

The small pipe that goes into the airbox commonly gets blocked, very common

Or

The seal between the air box's is also a common failure point, missing spring, damaged gasket broken or damaged fixings

But there are others

 

[koalar]

I wish thought to take some scan readings while mine was failing it would have been useful, diagnostic wise for others lucky enough to own a scanner

 

[Pugglt Auld Jock]

That seems like overkill, I can happily remove the MAP sensor and clean it occasionally instead, it's only needed doing once in 17 years so far

It was one of your posts elsewhere about cleaning the MAP sensor that made me try cleaning it, so thank you!

Thanks to @koalar as well for suggesting looking at the MAP sensor in the first place.

I looked at doing it but decided that just cleaning the sensor once a year was far easier. The fact that the engine is also port injected, so won't suffer the sort of inlet carbon clogging that it would if direct injected, also influenced me to go down this road. I think Catch cans probably have a greater effect for direct injection engines.

 

[koalar]

I looked at doing it but decided that just cleaning the sensor once a year was far easier. The fact that the engine is also port injected, so won't suffer the sort of inlet carbon clogging that it would if direct injected, also influenced me to go down this road. I think Catch cans probably have a greater effect for direct injection engines.

Depends on

The type of driving
Worn rings or valves
Leaking head gasket
Condition of the pipes and gaskets

For most people, it shouldn't be needed unless you are highly tuning the engine


The pipe that attached here also needs cleaning

Lack of carrying | FIAT Panda (Mk3)

hello everybody. i have panda 2010 1.2 manual gear that i bought. i was replace the all fluids (gear oil , engie oil , air filter oil filter , clutch , spark plugs, Breathe oil) the car not service a lot of time . after the service the car was drive well and feel good. but now after 2-3 months ...

www.fiatforum.com

I push a long handled screwdriver down, a garage told someone there is a flame arrester present, none of my three car have had one fitted, unless they have been removed by the previous owners (unlikely in my opinion)


As long as every thing is in good order it should self clear

 

[Pugglt Auld Jock]

Depends on

The type of driving
Worn rings or valves
Leaking head gasket
Condition of the pipes and gaskets

For most people, it shouldn't be needed unless you are highly tuning the engine


The pipe that attached here also needs cleaning

Lack of carrying | FIAT Panda (Mk3)

hello everybody. i have panda 2010 1.2 manual gear that i bought. i was replace the all fluids (gear oil , engie oil , air filter oil filter , clutch , spark plugs, Breathe oil) the car not service a lot of time . after the service the car was drive well and feel good. but now after 2-3 months ...

www.fiatforum.com

I push a long handled screwdriver down, a garage told someone there is a flame arrester present, none of my three car have had one fitted, unless they have been removed by the previous owners (unlikely in my opinion)


As long as every thing is in good order it should self clear

Felicity (Mk1 Panda Parade) had a wire mesh flame trap in her breather pipe which used to block up regularly because she did short journeys most of the time. I got fed up clearing it out so just left it out and never had a problem thereafter. Non of the more modern ones - Pandas or my boy's Punto - had them.

 

[PacoJones]

Pulled the air box off this morning and cleaned the large seal between the air box and the throttle body. Also cleaned the breather pipe that connects to the airbox, and the smaller pipe that connects to it.

I notice there's a lot of oil on the inlet manifold on the drivers side - see pic below.

I also feel that the large seal between the airbox and throttle body isn't particularly tight so perhaps not making a great seal. There's oil around the top of the throttle body as well, as per second pic.

I then drove the car and it was jerky again - pulled the MAP sensor, which I cleaned yesterday, and it shows oiling, so have cleaned it again.

Any thoughts? Replace the large airbox/throttle body seal at minimum, I think?

 

[Pugglt Auld Jock]

I notice there's a lot of oil on the inlet manifold on the drivers side - see pic below.

I also feel that the large seal between the airbox and throttle body isn't particularly tight so perhaps not making a great seal. There's oil around the top of the throttle body as well, as per second pic.

I then drove the car and it was jerky again - pulled the MAP sensor, which I cleaned yesterday, and it shows oiling, so have cleaned it again.

Any thoughts? Replace the large airbox/throttle body seal at minimum, I think?

The breather pipe between the cam cover and air filter box, including the small diameter pipe that connects onto the inlet manifold that you show to be leaking, tends to harden with age and doesn't seal onto the stub pipes. Becky was leaking at the wee stub pipe just like you show here. When i removed the air filter the first time the pipe felt as hard as if it was made from metal. I bought a new pipe from S4p as part of a larger order so i could get the discount, and it's never leaked since. If your pipe is still in good order maybe try a wee hose clamp? I've noticed on other Pandas that that wee pipe often has oil around it where it joins the wee manifold stub pipe. Messy but doesn't affect running. However do make sure the main pipe into the air filter housing isn't blocked with "gunge".

If you've cleared all the breather passages and hoses out and it's still getting a lot of oil contamination then maybe the engine is breathing too heavily? but that's a whole other question.

Edit. Has anyone suggested checking the "dogbone" stabilizer? You can get some pretty spectacular "jerkiness" if that's worn.

 

[koalar]

The oil around the joints shows it's leaking
It's missing the band's from the ends as well, fairly typical of a car of this age

Should be like this, mine had nice spring loaded clips, so it could just be pushed on and off

How long have you had the car

As a temporary test

Clean the MAP

Clean under the throttle body, just four bolts

And leave the larger breather off

Take it for a spin, see if the jerkiness come back

You can't leave like this as your polluting the environment but it should tell us if we are on the right track, or if it's a red herring

I see your is a cable throttle, the MAP on these don't tend to oil up as badly

Here what a fairly typical one looks like, they leak a bit but not wet

 

[MrMagoo]

They respond well to an Italian tune up, take it for a high speed blast.