HEAD GASKET GOING??? please help

[mrsseat]

Please help. my seat 1.2 seat 03 plate has a slight misfire and the engine management light comes on when the car is in traffic on a really hot day especially, or like today, it came on in traffic even though it isn't hot and the temperature gage on the dash isn't reading above the middle mark. took to garage as minor blow on exhaust and he said it was misfiring again and vagcom read misfire on No 3 cylinder. coil pack is new, spark plug OK. he has cleared code, but still misfires. He also put his hand over the back of the exhaust when trying to diagnose the blowing exhaust and commented there wasn't much pressure there. I don't want to buy a machine to read the codes as not sure if I want to keep the car,.
Background: Engine shakes on idle, heater is hot within quarter of a mile of driving from cold. Coolant temperature sensor has been replaced with the coil packs, Vagcom readings keep saying misfire on one of the cylinders but the plugs are OK and all new coil packs. Has anyone else had this problem, the engine shakes on idle, is it the head gasket on its way out.

 

[cheshire cat]

does it have 1 coil pack or 3/4? if one swap the leads and see if the misfire moves, then I would have a compression test or better still leak-down test done before anyone starts pulling things apart and getting expensive / maybe a second opinion

 

[mrsseat]

Thanks, took to garage who fitted coil pack on cylinder3 today, he swapped coil pack and fitted a new plug, problem still there and shows intermittent misfire on cylinder No3. He pulled off the injector to find that there was a difference to the other two, less petrol was going in he said especially as the plug was still whte (running lean). Garage are suggesting hours labour to swap the injectors around with a view to replacing it if it appears to be the problem.

Incidentally, 2013 the injector had to be replaced on cyclinder 1 according to the receipts I have,.

 

[Arkaig]

As suggested, a compression and leak-down test should eliminate any problems with the valves and cylinders. The timing chains on these engines can jump and cause valve damage.

The leak down test will also show if the head gasket is intact.