Hi all, i know theres already two older posts on this but ive read them both and not sure were to start.

last year i had my head gasket done, after that i noticed that my ecu light would come on around 75mph when on the motor way. i found that it was a 2nd cylinder missfire, so i replaced the leads and coils which fixed the problem.
ive been out in the car today to find the ecu light to come on and flash at me again only the once tho. i got the code read (p0300) which says its a random cylinder missfire.

i dont have a clue whats causeing it as the coils and leads are at most two months old.
Anyone got any ideas or does my punto look destined for the scrap head?

Thanks.

could be the lambda or even a plug amongst many other things

whats your MPG like?

hi jip0,

without making myself sound totaly thick i cant tell you my exact mpg, i can tell you off a full tank i can do between 320 and 350.

Check lambda, dry and wet compresssion test.

Hi all well ive done a dry test results are as follows

c1 - 150psi
c2 - 150psi
c3 - 100psi
c4 - 125psi

since doing the dry test im now spitting out blue smoke when im hard down. am i right in thinking c3 and 4 have about had it?

Certainly looks like a leak between the two.

Wet test (on 1 and 2) would give you a good indication of the state of the bores.

If the spark plugs from the low compression cylinders are cleaner than the other two, you have a head gasket failure. Water in the clylinders steam cleans the plugs.

i had the headgasket done just before xmas so now i keep a check on my water level and its not going down.

im just eating oil like theres no tomorrow. i filled it back up on friday and now its halfway down the dipstick in a week.
rocker gasket has been replaced and so have the o rings where it was leaking from i can see anymore leaks i dont leav any puddles on the floor that i can see and theres no drips.
the plugs in C 3 - 4 were pitted so im guessing im leaking oil into them specialy now ive done a dry compression test.

rang the garage i use and theyve said it would be far cheaper and quicker just to find a 2nd had engine and swap them over is that what im looking at? just ashame after all the work ive done to it.

its quite possible that when the headgasket went the upper cylinders in 3 and 4 got extremely hot which caused the compression rings on the pistons to lose their shape and so are now not holding the compression
easiest solution really is a s/h good lump

hi s and b without making my self sound dence what do you mean by s/h good lump ?

What S and B is so eloquently saying is....You need another engine