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.

 

Mmm. You sound very knowledgeable and better at electronic testing than me and I class myself as handy!

 

Anyway, I doubt it is the plug change. Although I've never used champion plugs in ea888 engines only the bosch or ngk aftermarket.

 

When you say the old ones in terrible condition. What do you mean. Worn or oiled and fouled up?

 

Does your motor have an oil consumption issue?

 

The two things that immediately spring to my mind are 1) timing chain slipped. You know about the tensioner? This could be showing itself as rough running, now no start and the correlation fault  or 2) faulty knock sensor or wiring to it causing engine misfire due to ecu intervention. But if signal tok high recorded not sure how much attention the ecu would be paying to that knock sensor.  

3 hours ago, zelea2 said:

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.

 

 

2 hours ago, TheClient said:

Mmm. You sound very knowledgeable and better at electronic testing than me and I class myself as handy!

 

Anyway, I doubt it is the plug change. Although I've never used champion plugs in ea888 engines only the bosch or ngk aftermarket.

 

When you say the old ones in terrible condition. What do you mean. Worn or oiled and fouled up?

 

Does your motor have an oil consumption issue?

 

The two things that immediately spring to my mind are 1) timing chain slipped. You know about the tensioner? This could be showing itself as rough running, now no start and the correlation fault  or 2) faulty knock sensor or wiring to it causing engine misfire due to ecu intervention. But if signal tok high recorded not sure how much attention the ecu would be paying to that knock sensor.  

 

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.

7 hours ago, zelea2 said:

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.

Ok.

 

Wow those plugs sound terrible. Don't know how it wasn't causing running problems. It will have caused more stress on the coil packs too but you have bench tested.

 

The ea888 gen 2 wasn't designed to use oil. The issue is the oil scaper ring clogging and then as the problem gets worse more and more oil is consumed. It eventually kills the engine but if your only just starting to see a slight increase I doubt you're there yet.

 

What amount of oil in every how many kms are you putting in?

 

The timing chain tensioner and in some cases the chain itself were poor design until at least end of first quarter 2012.

 

The chain can stretch beyond limits of the tensioner. Even without tooth skip this can cause correlation timing faults. 

 

But it is a well documented issue with many engines suffering loose chains that skip teeth especially as initial startup when the ratchet is relied on in the tensioner rather than hydraulic pressure.

 

There is an entire thread dedicated to the above 2 faults at the start of the forum pinned at the top. Don't read it, it will make you feel bad but the problems can be catastrophic and immediate.

 

I'm still scratching my head a bit as to what to recommend.

 

You could try the usual computer help desk fix of disconnecting battery and leaving for an hour then reconnecting. If you want to make the discharge faster touch the two batter leads together while disconnected.

 

Other than that, for the relatively low price of a compression gauge I'd get one that will fit in the deep recesses of the engine cam cover / cam girdle and test compression on all cylinders.

 

Beyond that the top tinmng cover can be removed to check timing.

 

There is also a small rubber bung in the lower cover,  that can be removed to look at the tensioner and how far it is extended when engine is static. 

 

 

Edited 30 June, 20223 yr by TheClient

If you like watching repair videos here is one on the EA888 Gen 2 (your engine) it may be the 2.0 version but in very many respects is identical design.

 

If you watch into a few minutes you will also see the inspection hole I referred to.

 

If you have a small inspection camera you may prefer to look inside the cylinders BEFORE doing a compression test as if the chain did happen to be loose and has not already caused valve damage, putting the engine on the starter could cause the collision.

 

They also show a measurement that can be done on with the top timing cover removed. Not sure if it is identical for the 1.8 / 2.0 in terms of the mm spec but I'm sure some googling would answer.

 

https://www.youtube.com/watch?v=hRAcxGdkcZU&t=84s

 

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?

1 hour ago, zelea2 said:

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?

Let us know what your inspection brings. Yours is bound to be the old tensioner design with the retainer ring. Look how far it is extended.

 

In the cylinder bores see what you can see but any cylinders that say showed piston collision or intake valves open accross more than one cylinder would be an issue.

 

If your comfortable. Compression test after that.

 

Well I'm pretty mechanically minded. Used to have motorbikes as a kid and a 240z track day car.. 

 

On the timing chain. It is doable. I chose to pay an independent to do it for me at purchase. Mostly because I don't have a garage, have to work on a gravel drive and at very least you probably need a engine sling to support removal of engine mount, a vw timing tool kit with camshaft lock and a crank shaft counter hold tool.  

 

Edit. Plus two more things. 1. If it takes an experienced tech say 5 hours,it would take me 2 days  also, without a lift undoing things like the crank bolt are very difficult from ground level. Even when I've done jobs like brakes, caliper carrier bolts from lying on ground - can be very difficult. But the job is doable fir the persistent and detail minded diyer. 

 

Let us know how you get on with inspections. 

Edited 1 July, 20223 yr by TheClient

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?

7 hours ago, zelea2 said:

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?

 

 

Oh dear.

 

zero psi in all cylinders is not good.

 

It would be impossible to start an engine at all with 0 psi in all cylinder.

 

So, yes, it seems to me that it has to be that starting the engine when running rough has caused further slippage and possible overhead cam gear or valve damage.

 

If you're really lucky I guess it has slipped enough to cause zero compression but not hit the pistons given your inspection.

 

A better or different field of view borsescope would be useful to see if the valves are still moving. Or you could take the intake manifold off, a few hours job, probably 3 hours to disassemble first time though. Does give you a chance to decarbon the intakes and get injectors tested and cleaned.

 

Yes, if you want to remove the upper cover you will need a trolley jack and a wide piece of wood to support the engine on the sump. Jack until it has taken pressure. Remove engine mount.  This should allow you to check the timing marks and distance per specs. But it seems impossible to explain sudden and immediate zero compression on all cylinders with any other cause especially with the pistons confirmed as intact and moving.

 

Did you perform the compression test on the starter motor. Several times?

 

Edit: By the way. that is an old style tensioner. Very susceptible to failing but doesn't look like it has failed totally in the normal way. However, it looks a long way extended but I can't count the teeth due to the angle of the shots. Access is better with engine mount off.

 

Edited 5 July, 20223 yr by TheClient

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.

19 minutes ago, zelea2 said:

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'd probably start by removing the upper plastic timing cover.   This would allow you to measure distances from the links. You could also try to feel for chain slack, although not sure how successful that would be as it is right at the top at the sprocket.

 

I can dig you out some instructions if you want. DAP / Humble mechanic has a couple of good videos as they do a lot on the 2.0 tsi. The 1.8 is of the same ea888 family. The Erwin repair manual which will probably cost about 10 euro for access not a bad idea before embarking on the project.

 

Another thought, if you take the pcv / fine oil separator off the top of the engine you can see in the cam cover particularly the intake valves lobes and actuators.   This is a fairly quick job 30 mins. Be careful with the plastic tube connectors (fragile) and do not drop anything into the aperture where it is removed. But I am virtually certain you have a slipped timing chain. The questions is, is there valve damage? 

Edited 5 July, 20223 yr by TheClient

It's highly unlikely you have Zero compression on all cylinders. Even a badly trashed piston/bore will make some pressure or make the guage move for a bit. I recon you have done something wrong with the kit.

In case you are doing something silly with the compression tester (we have all been there!) simply push your thumb over the spark plug hole while someone cranks the engine, if it is not blown off of the hole then you have zero or as close to zero as matters compression.

 

No doubt on your engine the plugs will be recessed, you may be able to get a finger down there, if not then improvise with something long rubbery and flexible 🤣

 

Did you by any chance turn the engine by hand or by pushing the car in gear during your earlier investigations? If it turns over backwards with a worn or failing tensioner its usually game over next time the engine is cranked.

1 hour ago, Golf-Fiend said:

It's highly unlikely you have Zero compression on all cylinders. Even a badly trashed piston/bore will make some pressure or make the guage move for a bit. I recon you have done something wrong with the kit.

It only needs valve to be slightly bent for zero compression, if one gets hit by the piston then those on

the other cylinders will also

48 minutes ago, J.R. said:

It only needs valve to be slightly bent for zero compression, if one gets hit by the piston then those on

the other cylinders will also

Yes, I tend to agree. An engine running, then roughly, then nothing. And now no compression, on any cylinders .  I'd be thinking that bent valves are the result and timing chain slip the cause. 

Have you read the first thread in this forum which is about timing chain failures?  On page 7 you will see information on the fault codes which could indicate that this is the problem affecting your engine.

15 hours ago, DGW said:

Have you read the first thread in this forum which is about timing chain failures?  On page 7 you will see information on the fault codes which could indicate that this is the problem affecting your engine.

That tpi is helpful but not complete by any means. A fault code is not guaranteed and the op has the crank to cam correlation which is not menrioned in that TPI but is often an indicator. 

You were right, all my inlet valves in all cylinders are bent. The exhaust valves are fine though. I've bough this week a quality borescope which has dual cameras one pointing sideways.

With this lateral camera I can see very well all valves and inlet ones are all opened and bent.

Since the bending happened while I was cranking the engine with no combustion in the cylinders I am hoping the damage is not too severe.

If a buy a timing chain kit and a full set of valves would this be enough for a garage to repair my engine?

Photo 3 appears to show the piston crown broken off at the edge exposing the top piston ring, no decent garage would ever reassemble an engine with that.

 

I would say that it needs 4 new pistons as well.

Ouch! Looks nasty! Hope you can get it fixed at reasonable cost. Something like that might cost more than the value of an 11 year old car.

1 hour ago, J.R. said:

Photo 3 appears to show the piston crown broken off at the edge exposing the top piston ring, no decent garage would ever reassemble an engine with that.

 

I would say that it needs 4 new pistons as well.

 

5 hours ago, zelea2 said:

You were right, all my inlet valves in all cylinders are bent. The exhaust valves are fine though. I've bough this week a quality borescope which has dual cameras one pointing sideways.

With this lateral camera I can see very well all valves and inlet ones are all opened and bent.

Since the bending happened while I was cranking the engine with no combustion in the cylinders I am hoping the damage is not too severe.

If a buy a timing chain kit and a full set of valves would this be enough for a garage to repair my engine?

Bummer.! That third photo is a worry. It does look like a chip but is right on the edge of the piston pre-made relief isn't it?

 

I fear the whole job is becoming uneconomic unless you're very attached to the car and would like to spend a substantial sume to keep ot for another say 5 years plus?

 

That head repair with 8 valves and possible valve guides reseating etc. How much would an engineering shop charge.

 

I know is the us garages usually go for a vw exchange head for piece of mind and speed. And the retail on the whole job incl timing chain is around 4k USD. Imagine it would be similar in euros.

 

And you've still got this potential piston replacement. And even if not, increasing oil usage. 

 

I guess if you did all the disassembly and reassembly it could just about justify itself. But it's a big job even without pistons rings, and the upgraded parts required new conrods from memory as well.

 

So sad and disappointed for you. 

 

I'm in UK and I've looked for used engines and they go for 2700-3000£ and for the engine head only 700-1000£.

Garage labor is also quite expensive in this country so it won't be worth economically to fix it.

It seems I'm joining the ranks of people with catastrophic engine failures all thanks to one badly designed tensioner.

1 hour ago, zelea2 said:

I'm in UK and I've looked for used engines and they go for 2700-3000£ and for the engine head only 700-1000£.

Garage labor is also quite expensive in this country so it won't be worth economically to fix it.

It seems I'm joining the ranks of people with catastrophic engine failures all thanks to one badly designed tensioner.

Yeah. The trouble with a used engine is a) has it had a updated and revised chain and tensioner and b) how severe oil usage does it have, has it had the upgraded pistons, rings, conrods?

 

the realistic likelihood of being able to confirm all that on a used engine is very very  unlikely. So what you really need is a rebuilt engine for even more £s.

 

Unfortunately, you are very much not alone in this. And problems with stretched chains and failed tensioners go back before the ea888 and has affected other makes as well.. but none of that helps you. 

17 hours ago, TheClient said:

I guess if you did all the disassembly and reassembly it could just about justify itself.

I haven't completely given up on repair. If I sell the car as is I will probably get only between 300-500£ which is a real shame.

My family has two other cars so we're not pressed to repair the Skoda Octavia quickly.

I will probably buy another used car in the short term and try to repair this one over the coming months and then either sell it or keep it for my son.

I can buy all the tools and components for the repair before starting this big job.

I have plenty of space and a big garage at my residence but I don't have an inspection hole under the car or a car lift so I won't be able to remove the engine.

Is it possible to remove just the engine head and the timing chain covers if I buy the proper engine support? Has anyone done this?

23 minutes ago, zelea2 said:

 

Is it possible to remove just the engine head and the timing chain covers if I buy the proper engine support? Has anyone done this?

Yes. The timing chains and head can be done from above. An engine support bar would be useful.

 

That piston skirt damage is where you're going to come unstuck though?