zelea2

Yes compression was on the starter motor (I'm keeping the battery charged after all these cranks). The compression kit has a hose that screws in place of the spark plug and also a solid aluminium tube with a rubber cone at one end. I've tried both in all cylinders and it reads zero all the time. In some of the images you can barely count the teeth on the tensioner piston - I see 3 teeth.

I've used my inspection camera and looked into each cylinder but I couldn't see any problem. The piston surfaces look clean, I can see the two recessions and no marks on the surface. I couldn't see any valve though, those sit back from the camera and I guess the filed of view is not wide enough to see them (not visible even when the camera enters the chamber). I've also bought a compression test kit, cranked the engine and I have no compression at all (0 psi) in all the cylinders. Since it's the first time I use this kit I check it is working with my bicycle pump and it was. Again I hear no metallic noises when I crank it. I've placed a carbon fiber rod in each cylinder and hold it with my hand to check that all pistons travel up and down, no problem there. I can see through the oil port that the inlet camshaft is rotating and one valve rocker is visible and moving while cranked so I don't have a broken timing chain. I wanted to look at the upper part of the timing chain but I found it impossible to take the plastic cover off. I have access to the upper 3 T30 screws but the lower 2 are blocked by the engine support. Is it worth/possible to remove just the upper cylinder head cover by having just those 3 screws off and leave the chain cover in place? (I was thinking to check manually and visually that all valves can travel freely) I've also accessed the tensioner port and took some pictures. It was a lot of work to get there: I hat to take the wheel off, then some 20 torx screws to get the wheel arch off and a I had to disconnect a thick air hose which was sitting exactly in front of it. Are these a definite symptom of timing chain slip? Before changing the plugs the engine still started but rough. Did the chain slip further when I've cranked the engine with no plugs in? Is it normal to have no compression in all the cylinders or could could it be another cause as well?

Thanks a lot for your suggestions. I do have a small USB camera that I can use to look into the cylinders and the inspection hole. I'll do that over the week-end. I don't think I have any valve damage yet because I haven't heard any metallic noise while the engine was still running and also while I crank it there is no suspect noise. I did disconnect the battery for a few hours and that still hasn't produced any fault code. If I have a tensioner/chain problem do you think replacing it is something I can do at home (I'm pretty well stocked as tools) or it must be a garage?

I don't know much about engines but my job is electronic design. The old plugs were covered in soot and had corroded tips; one had a warn out tip with the gap exceeding 1.5mm when it should be only 0.75mm. Yes the oil consumption increased lately (but there is no oil leak). I've read somewhere that this engine consumes more oil than others because of its design. In the last few months I had to top the oil more often than usual though. The knock sensor is just a piezo and I don't think it breaks easily. This is equivalent to a capacitor so even with broken wires that should not prevent a start. Car hasn't moved between engine working fine then engine working rough with vibration and finally engine not starting. How can a chain slip? It is not a belt. I've never opened the timing compartment because that's on the left side of the engine and I have to remove a lot of parts to examine the timing chain. I also believe that the ECU is in some kind of safe mode and doesn't trigger the spark plugs. When I've temporarily disconnected the G40 sensor it appeared immediately as a fault. What intrigues me most is why the engine controller doesn't give me any error.

I have an Octavia MK2 1Z3 from 2011. When I've arrived home one night the engine was smelling hot but I had no dashboard fault and it was running fine till then. Next morning when I've tried to start the engine it was vibrating strongly and very noisy almost like not all the cylinders were firing. I've connected the car to VCDS and it was showing the following errors: 000022 - Bank 1: CMP Sensor (G40) / Engine Speed Sensor (G28) P0016 - 000 - Incorrect Correlation - MIL ON 000808 - Knock Sensor 1 (G61) P0328 - 000 - Signal too High 000768 - Random/Multiple Cylinder Misfire Detected P0300 - 000 - I took all the spark plugs out and they were in very poor condition. I've replaced all of them with Champion CET11P new ones. Since I've replaced them the engine doesn't start any more when it is cranked. I took the spark plugs and coils out and bench tested all of them. The coils connectors have 4 pins, I've placed ground on pins 2 and 4, +12V on pin 1 and while touching pin 3 trough a 470 ohm resistor to 12V I had very nice sparks on all. I've also measured the coil connectors with the key in contact. All have +12V and Gnd but when I was cranking the engine there was no impulse on pin 3 coming from the ECU on any of them. I've used an oscilloscope to catch these impulses and it was not triggering. Now there is also the possibility that pin3 needs a load to ground to see this impulses - this I haven't tried. I've also replaced the CMP sensor G40 (with a Bosch 07L905163) and that made no difference. The G40 sensor is a Hall sensor powered by 5V and the middle pin is open collector. Before getting the replacement I though it was push-pull and that made me suspect it was defective but it was not. If you power the sensor with 5V and place a pull-up resistor from its output you can see the signal being pulled low when you place a metal object in front of it. The engine speed sensor G28 also seems to work fine, when I crank the engine the VCDS shows the engine speed ramping up. What else should I check? After clearing the above faults the engine doesn't show any fault code any more but none of the cylinders fire. All fuses are intact both in the engine bay and the driver side. Could something have happened when I've cranked the engine with no coils and no spark plugs in? Should I check if the injection pumps are still delivering fuel mixture inside the cylinders? So to resume I have no engine fault but none of the cylinders are firing.