i have an 1.2 palio that blew an top gasket because it lost water thru 1 of the ac heater pipes. we bi past the heater to prevent it from leaking water and redone the top. it then run well for about 2 weeks but then burnd an outlet valve. could this have happend because of the bi pass, i see there is a water pipe that runs thru the weber inlet housing. this pipe has also been blocked off. or what else could have caused the burnd valve? please help?

what colour are all 4 spark plugs ?,
you MAY have a different issue..,
if it's JUST the 1 cylinder then it's unlikely to be the throttle body.. as that obviously feeds all 4 cylinders,

did you have the cam + valves out for the head rebuild ?,
maybe something has moved / disturbed.. to mess up clearances and upset the valves seal..??
Charlie

valve stem seals replaced with new ones and valves has been reseated

i would also like to know why there is a water pipe thru the throttle body? should i try to reconect this to the water, or can i leave it as is?

i cant say what colour the plugs are. they are stil in the top at the engineers who are replacing the valve. i have asked them to re check all the valves. number 2 silinder with the burnd valve had no compresion at all and number 4 only had about half its compresion so there might also be a problem there that aint visible yet. the piston rings seems fine, but i am coing to replace them as well. i would just like to get to the root of the problem to make sure i dont end with a nother burnd valve.

what were the valve clearances like after a couple of hours running ?,
as I said things DO settle..,

the water running through throttle body is to reduce "carb-icing",
are you at altitude..?? ,

Charlie

[QUOTE

the water running through throttle body is to reduce "carb-icing",
are you at altitude..?? ,

Charlie[/QUOTE]

It's an old trick to get some more horsepower.
When you live in a warm climate, you can leave the pipe of.

i have no idea what the valve clearances were. as it is done by an engineering place. i am only going to replace the complete top when they are done with it. i am in nice warm climate, so thanx, that pipe can stay of then. could there be any thing wrong with the throttle body? can it be tested?

ok the car is running again. but why does it sometimes revs up for no reasen?