Hi Team

I had my Siena 1.6 engine redone after overheating. It starts fine but seems to have fault on No.3 cylinder. Not sure if the mechanic got the valve clearance wrong or what but he gave up on the car. It drives but has no enough power. I have spare engine parts, so I fitted a complete intake manifold with injectors with no change and changed the coil with still no changes. There's also no change when removing the spark plug lead on that cylinder. It however does not burn oil, so I reckon the cylinder bore is still fine. What can be the problem?
If you can recommend someone who can get this car right it will be highly appreciated. I prefer the mechanic attending to the car where its parked as I cannot afford any further damage by driving it. Please give me a ring on +27 823860914

those HT cables are really delicate they break for nothing check for continuity with a meter some time if you use a secondhand cable you may use a broken one, also is the spark-plug black?

I swapped the HT cables around but with no change in performance or anything. The spark plug is just normal and not black

So I guess the car is losing some of its torque, did the mechanic run a compression test and an engine/cylinder leak test for each cylinder ? If you done this and I guess you did it, check for the ignition and fuel system again maybe you missed something, maybe the fuel pump or filter, or even something with the PCM, did the mechanic adjusted the valves clearance according to the car manual ? If he did it, I recommend checking the air intake system and all car sensors with the PCM/ECU codes and operation.