Hi there, I've got a 2004 1.2 8v with 110k that's developed a sudden misfire on cylinder 3. I noticed the power drop whilst i was on the motorway so i came off at the next junction and found the car misfiring. I got a tow home and took each pug out. All look healthy except the one in cylinder 3 which was wet with petrol.

I thought it might be the coils, leads or the spark plug itself but to no avail, its still misfiring. I've got a registered version of multiscan and found no error codes, or issues with the coils, ignition system or injectors.

I do believe there is a leak from the inlet manifold that i have been aware of for some time (oily residue around 2 of the spark plugs) but had been running fine before when I was aware of this.

Does anyone think it could be hg, valve or piston ring related?? Where do I go from here?

Hi mate,

When you say its not the plugs/ht leads or coils, is that because you have changed them? or because you have no codes on MES?

Any loss of coolant?

Next step would probably be compression test to ascertain if you have sufficient compression.

Alan

a1ant said:

Hi mate,

When you say its not the plugs/ht leads or coils, is that because you have changed them? or because you have no codes on MES?

Any loss of coolant?

Next step would probably be compression test to ascertain if you have sufficient compression.

Alan

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Yes i've changed everything and there are no fault codes stored in the system. I've even had the car running, with the software running to see if it detected a misfire and it said no, which leads me to believe there is a mechanical issue. I shall carryout a compression asap.

I would pull the ignition lead from the suspect cylinder and put a spark plug in it to see if these is a spark.

I would be suprised if you've lost compression through the cylinder without oil / water on the plug..,

have you swapped the plug leads over from coil pack to coil pack ( it's a "wasted spark system")

EDIT..,
I suspect it is still burning the fuel though..as you've not had the lambda flag up unburnt fuel,

checking the valve clearances may be the simplest 1st mechanical test..!!

Charlie

Hi again folks,
Just carried out a compression test:
Cylinder 1 - DRY - 15.5bar WET - virtually no change
Cylinder 2 - DRY - 15.5bar WET - virtually no change
Cylinder 3 - DRY -Needle hardly moved Wet - Virtually no change
Cylinder 4 - DRY - 15.5bar WET - virtually no change

Is this suggesting cylinder head problem? :bang:

With 110k on the clock - is this worth considering:

http://www.ebay.co.uk/itm/FIAT-PAND...arts_Vehicles_CarParts_SM&hash=item33891c6bcb

GeorgeDamper said:

With 110k on the clock - is this worth considering:

http://www.ebay.co.uk/itm/FIAT-PAND...arts_Vehicles_CarParts_SM&hash=item33891c6bcb

Click to expand...

How much do you think the labour would be for fitting a new engine?

There's a couple of prices on this thread:

https://www.fiatforum.com/punto-ii/336166-cost-fitting-new-engine.html

Hi mate,

So no compression on cylinder 3. Id suspect possibly exhaust valve. Compression looks good for 110k on the remaining cylinders. With piston rings or a cracked head youd expect some compression at least.

Alan

a1ant said:

Hi mate,

So no compression on cylinder 3. Id suspect possibly exhaust valve. Compression looks good for 110k on the remaining cylinders. With piston rings or a cracked head youd expect some compression at least.

Alan

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that's why I suggested checking the valve clearances

labour would be "enough" I tend to do my own work..,

Benny got an engine in his 1242 punto changed for @£120..
all down to what you get a new engine for..but personally I would consider just a head job..1/2 days work..and as long as you've looked after it the bottom end on yours should do another 50K without issue,

usual quandry with a motor swap is,
do you do the clutch, starter motor, etc..

it all adds up, and you're fitting another "used" engine.

Charlie

varesecrazy said:

that's why I suggested checking the valve clearances

labour would be "enough" I tend to do my own work..,

Benny got an engine in his 1242 punto changed for @£120..
all down to what you get a new engine for..but personally I would consider just a head job..1/2 days work..and as long as you've looked after it the bottom end on yours should do another 50K without issue,

usual quandry with a motor swap is,
do you do the clutch, starter motor, etc..

it all adds up, and you're fitting another "used" engine.

Charlie

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The car is very well looked after, that's why i'm shocked by whats happened. The only thing I neglected over the years was valve clearances, but i did have them checked 6 months ago and some were on limit of being tight but the mechanic said leave alone, guess I've paid the price now.

Would it be worthwhile getting the head reconditioned or buying a second hand cylinder head?

AAB1992 said:

The car is very well looked after, that's why i'm shocked by whats happened. The only thing I neglected over the years was valve clearances, but i did have them checked 6 months ago and some were on limit of being tight but the mechanic said leave alone, guess I've paid the price now.

Would it be worthwhile getting the head reconditioned or buying a second hand cylinder head?

Click to expand...

Hi,
I'm more than happy to talk you through a head removal,

you should then see what the piston crowns / bores are like yourself, however it's pretty simple to have the cam-cover off and measure the clearances yourself..around 1 hour ,
Charlie

varesecrazy said:

Hi,
I'm more than happy to talk you through a head removal,

you should then see what the piston crowns / bores are like yourself, however it's pretty simple to have the cam-cover off and measure the clearances yourself..around 1 hour ,
Charlie

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Well I think under the circumstances the head certainly needs to be removed and sent to a machine shop. I've got most of the tools required, just concerned about putting things back together and making sure everything is torqued sufficently

AAB1992 said:

Well I think under the circumstances the head certainly needs to be removed and sent to a machine shop. I've got most of the tools required, just concerned about putting things back together and making sure everything is torqued sufficently

Click to expand...

Head gasket is pretty straightforward,
you will probbly do well to lap in new valves where necessary,
or price up a guaranteed rebuilt head,
I'm happy to walk you through it.. did mine ( H.G.)3 weeks ago

allow 1 full day , and 1 persons labour ( assistant for head lift-off maybe),



never needed to skim any of my FIAT heads,
as long as you don't repeatedly boil 'em dry they are pretty forgiving,
just check for flat with a straight edge,

Charlie

Hello there again,
Me and my friend manged to get the head off, took us around 3.5hrs, not a difficult job, just lots of cleaning on the block and inlet ports to do.
Once it was off i discovered the horrors! Cylinder 3 exhaust valve has a substantial chip missing!

Any idea how this has happened??

well done..,
said it wasn't too bad..!!

when you say CHIP.. has it square edges like a mechanical break

..or more rounded = burnt away..??,

Charlie

varesecrazy said:

well done..,
said it wasn't too bad..!!

when you say CHIP.. has it square edges like a mechanical break

..or more rounded = burnt away..??,

Charlie

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Hopefully it shouldn't be too costly to sort out!

The only issue is that the engine has moved out of place whilst it has been sat on the jack, hopefully i can move it back into position when i refit the head.

To make sure the job is done properly, how clean does the block need to be to ensure it seals properly?

Do the new head bolts need oiling when i put them in?

Would it be worthwhile purchasing a torque wrench that does angles as well? as i don't have one at the moment

Many thanks, Adam.

AAB1992 said:

Hopefully it shouldn't be too costly to sort out!

The only issue is that the engine has moved out of place whilst it has been sat on the jack, hopefully i can move it back into position when i refit the head. weve all done that one

To make sure the job is done properly, how clean does the block need to be to ensure it seals properly? clean clean,use xome petrol if nothing else to hand

Do the new head bolts need oiling when i put them in? no no no

Would it be worthwhile purchasing a torque wrench that does angles as well? as i don't have one at the moment the angles are angles ie a 1/4 turn is 90 %

Many thanks, Adam.

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make sure you put the headgasket on the right way or there will be no oil going up
also you need to carefully check the bore where the valve broke to make sure no marks or the pistons rings will break within a day,usually these bits get kicked down the exhaust so hopefully its rattling about on top of the cat guaze
one just knew it was a valve from the start of the thread,i might have just changed the complete head mind just in case the valve stem moves in the coming weeks

Well the head has been send the machine shop to be looked at and I've just ordered the head gasket set. The Fiat parts department that I spoke to said i'm fine to reuse the old head bolts, what are your thoughts on this??

When cleaning the block, do i need to use anything else besides thinners, like fine sand paper or razor blade?

I'm just worried about putting dirt down the bores and oil ways and then trying to clean the debris out.

Does anyone have some good cleaning tips and things to look out for?