Hi all...

I have a 1999 ford fiesta zetec si 1.25 ... When i bought the car 3 weeks ago the previous owner said that there was a slight misfire and ahe had been told the spark plugs needed o be changed and that there were spare spark plugs in the car.


Yesterday a friend tried to change the existing plugs to the plugs given... He noticed that these plugs were not brand new ... The car was terrible it had no power and was just juddering like crazy ...

It was my friends lunch break so we thought perhaps the plugs were bad so i drove to get new ones for him to fit later ... Whilst driving the car was terrible and at one point there was a huge sort of gust like your heater comming on for ten seconds ... The temp gauge does not work so may have overheated....

Later on we then changed to the new plugs...tested the leads and coilpack ... But the car is now undrivable and constantly judders but a bit more power.than the other plugs and every 30 seconds a loud noise comming from the front right of the car (looking at the car) i think sort of airbox direction but more towards the engine like a sort of rattly box noise ... Any ideas greatly appreciated ... Also im no really up on cars so have to be plain speak .... Many thanks for reading this

 

could it be misstimed or , maybe a stuck/bent valve, allowing a pop and missire to head back up through inlet making noise in the air box, try a compression test

 

Thanks for you reply...

How do i do a comppression test? Would that explain the manic juddering? Do you think i damaged the car by driving with perhaps the spark plugs dodgy.

Many thanks for your time

 

you'll need a a compression test tool, its a guage that screws into the spark plug hole, when engine is turned over it gives areading on the guage, not sure where youd find what its meant to be, but if you do it and one cylinder is lower than others then you know you have a problem , not sure it would cause any damage to engine with misfire , maybe the cat will be damaged though

 

On the 1.25's I'd be getting a CO check done at a mot station, could well be the lambda, which is fairly normal on these, I'd do that first.
10 minutes to swap over for a new one, if duff will make a world of difference, easy to get to as well, but can be sod to get undone, as in being super tight.
tabetha