hey guys,

I'm a bit new to cars and engines but i know my way around them enough to understand :) the cars a 51 plate 1.4 16v polo eng: AUA

the problem is since i got my 6n2 its had a slight misfire, it wasnt a massive deal at first and wasnt really noticable when i bought the car, slowly its been getting worse and now its making the car run a bit poop :( iv got a few friends that are mechanics and one plugged it into diagnostics and found it was in cylinder 1 but that was pretty much all it could tell us, they have all suggested different things to replace heres the list

-coil pack

-HT leads

-spark plugs (only channged in febuary)

-EGR valve

and then today i get told off a garage that have had the car in before i had it that they think it might be something to do with a valve inside the engine

does anyone have any experiance with this?

or know how to check each part to source the problem?

just dont want to go and spend £££'s on parts that wont solve the problem :( or even let a garage spend my money on tea breaks not to get it sorted :(

any help at all would make a massive difference :)

thanks all in advance

Try removing the spark plugs, but keep them in the order that they were in on the engine.

Examine the 'business' end of each plug, looking for contamination, burnt electrodes or large amounts of carbon build up.

If the plugs look OK, put them beck into DIFFERENT cylinders to which they came out of.

If the fault now moves to another cylinder, that plug is faulty.

Another test which won't cost the earth, is to do a compression test. This will either confirm or eliminate what the garage have said.

If you know anyone with the same model car, you could try asking if they would mind you swapping plug leads, coil pack etc, just for diagnostic purposes, this too wouldn't cost anything.

Regards.

Try removing the spark plugs, but keep them in the order that they were in on the engine.

Examine the 'business' end of each plug, looking for contamination, burnt electrodes or large amounts of carbon build up.

If the plugs look OK, put them beck into DIFFERENT cylinders to which they came out of.

If the fault now moves to another cylinder, that plug is faulty.

Another test which won't cost the earth, is to do a compression test. This will either confirm or eliminate what the garage have said.

If you know anyone with the same model car, you could try asking if they would mind you swapping plug leads, coil pack etc, just for diagnostic purposes, this too wouldn't cost anything.

Regards.

thanks mate

i do mean to check the plugs just haven't had the time recently

will a garage do a compression test? i dont have a tester and if its relativly cheap i can cope with it being done properly

unfortunatly noone i know has a 1.4 they are all 1.0 which kind of sucks

if i do happen to get nowhere and end up replacing all the parts what order would you suggest?

If you resort to 'guessing', then go for the cheapest first, maybe plugs, leads and then coil pack.

BUT you could replace all of these and not effect a cure.

There is a (slender) chance that one of the cam lobes is worn, so you could remove the cam box cover and compare the height of the cam lobes of one cylinder with those on another - again, this wouldn't cost you anything other than time.

It might even pay you to buy a compression tester, it is a piece of equipment that you may wish to use many times in the future.

Again for nothing, you could try cleaning out the EGR valve.

If this problem is mainly at idle speed, you should also be checking for vacuum leaks on the inlet manifold.

Regards.

Okay thanks will see what happens and blag a few favours from friends haha changing everything will be the last resort think I might dump it at a garage to look at it before then :p

And it effects the engine on and off not just at idle sometimes it will be fine and then other times it just has no power whatsoever and struggles to pull

Thanks for all your help I know it's a bit of a ball ache but I do appreciate it alot :)