Technical The ongoing "Shudder"

[Jelly Bean]

Dear all,

Our little MPi Seicento has a very slight shudder or appears to miss a beat when it is idling. It is smooth as silk when starting up from cold, but after about a minute the shudder appears.
Its not terminal but annoying !
We have had it for 2 years and has always had this little characteristic.
In that time it has been looked after by fiat, has new plugs, leads, air filter, lambda sensor, crank sensor, thermostat & cambelt. Its cylinder head gasket has gone and been replaced and head skimmed ( by fiat ££ ouch ).
I have "heard" that "they all do this",,, so please, put me out of my misery.
Am I on a quest to fix the unfixable or can anyone suggest what could be wrong !
Many thanks
JB

 

[randomizered]

don't speak to ronnieronson

mine always juddered/was bit lumpy a bit at idle, its the way they are. Low rpm at idle to reduce emissions.

If the judder is excessive, somethign is wrong.

Compare it to a few other MPI seis to see how they are.

Kristian

 

[Brooky]

you want to hear mine then, sounds like its missing all the time just the exhaust setup

 

[Jelly Bean]

Thanks !

I won't end up pooring cash at something that Is normal !!!

 

[mrcinquecento]

nah, seems to be fairly normal, my sei feels as though its running on 3 cyliders for a second very occsionally at idle, and gives a bit of a shudder, just give it a tiny bit of revs and its absolutley fine for as long as you hold it there. its just the idle set up as kritip says

 

[ronnieronson]

don't speak to ronnieronson

mine always juddered/was bit lumpy a bit at idle, its the way they are. Low rpm at idle to reduce emissions.

If the judder is excessive, somethign is wrong.

Compare it to a few other MPI seis to see how they are.

Kristian

Lol

....that said she idles lovely and smooth now that I have the janspeed mani on - still judders a little, but no more so than any other mpi Sei.

 

[Ralf S.]

Is it really a "shudder" or does it sound like a "misfire"?

Open the bonnet and have a look at the engine. If it's moving around a lot, then you could have a failing engine mount. The engine won't fall out, so it's not as alarming as it sounds.. just the rubber bush starts to fail and lets the engine flop about a bit.

But you would notice the shudder at low engine speeds, if the car is stationary or moving.. at higher speeds (30mph) it will go away.

Ralf S.

 

[_Ben]

my seicento citymatic always shudders when idle sounds a bit unnerving but hopefully its normal