Fiat Punto ecu fault?

[sospan]

My son has a Punto 1.2 bought second hand from a Vauxhall dealer it has 1 year HIghQ warranty.
Within a week the engine management light came on.
Vauxhall dealer sent it to a Fiat dealer who changed leads/plugs - still the same so taken back to Vauxhall dealer
They returned it again to Fiat dealer who fitted a recon emu
No improvement
Fiat dealer now THINKS its sticking valve(s).
Car has done just over 30K
Excuses given include
" Petrol additives causing the problem - standars petrol used from pumps!!!"

The Fiat dealership has the car back to sort the valves(????)
My problem with this is:
If valves ARE sticking then what effect will this have longer term on
a) Pistons etc
b) Camshaft/timing gear
I have told the Vauxhall dealers i do not accept the car and want a refund under Sale of Goods Act.
Temporarily my son has been given a courtesy car while the "valves are being sorted"
I am very reluctant to accept the car as i am not happy that there will be no long term problems due to unknown mechanical problems building up due to the initial problems with ecu light showing and Fiat dealerships inability to diagnose the problem.
Any comments on what could be the problem and what long term problems may ensue?

[banzai_dan]

I'm no expert but I don't think that your problem is sticking valves. The symtoms of sticking valves are rough idle, a funny noise coming from the top of the engine (don't know how to describe on a computer), slight loss of power, misfiring, even failing to start depending on the severity of the sticking. I don't know if you've been experiencing any of these symtoms, but as you've only mentioned the ECU light then I asumed that the car is running fine except for the light.

The trouble with ECU lights is that it could be showing a fault with any one of the multitude sensors on the car, or there could be a coroded/loose conector somewhere and its a nightmare to check them all. So IMO you've just got a fault with the electronics, probably got a faulty sensor somewhere.

IF it is a sticking valve then it can be quite expencive as the head needs to be removed and taken apart and taken to pieces, which leads to big labour bills. So often the garage will fit a reconditioned head, which is still expencive.

sospan said:

" Petrol additives causing the problem - standars petrol used from pumps!!!"

There have been a lot of people saying that fuel additive/cleaners that they've added to their tank have causes sticking valves. You said that you've only recently purchased the car, so perhaps the previous owner used additives.

However ask the dealer if they are 100% sure that it is a sticking valve before they start taking the engine apart, as it could be a big waste of time and money, if the ECU light comes straight back on imediatly after fitting a reconditioned head.

[sospan]

Thanks Dan.
Those wre my thoughts about the valves too.
The garage said that the additives were the normal ones in forecourt petrol not bottled pour in ones!
I agree that its probably a sensor/wiring problem.
If it IS the valves then i am reluctant to accept the car as its only been bought about 6 weeks. Its spent half that in Fiat dealers. It has a 1 year High Q warranty but i am concerned that a Fiat dealer can't find the problem and they seem to be fishing for the fault rather than proper diagnosis.
My son has a courtesy car and it wont be returned until either the fault is sorted or we get a refund under sale of goods act
sospan