[zk_EU]

Hi!

Hopping someone could shed some light my problem

For a long time now I have a problem with a pending P0300 fault (meaning several cylinder misfires identified) with supposedly light engine pinging/pinking. The pinging is not hearable (not even in the garage), at least I don't hear it and I know how light to medium pinging already sounds like. The car is an Astra J, 1.6 NA petrol engine (A16XER).

What happens.

At idle when keeping the reavs around 2.500 RPM or on a level road with really light engine load (under cruise control or without) and where the engine is in a closed loop, pinging occurs on all cylinders which I can see on the diagnostic. It logs a lot of pinging on cylinder 2 and 3 and less on cylinder 1 and 4, but also. It will also log pinging with a completely cold engine, if I give it some revs at that time (moderate, not high revs of course). Opel/Vauxhall goes into a closed loop very quickly, less than a minute after a cold engine start.

When it detects a larger number of knocks/misfires, it will turn off my ESP, (displayed warning on the dash: SERVICE STABILI TRACK and occasionally will result in a flashing MIL (le'ts say 1/4 of the cases) will appear, but it always goes off completely after about 30 seconds. It also stores a historic U0100 in the ESP/brakes module, but I know this is duo to the pending P0300 faults. As for the P0300, it will never log an actually P0300 fault, it will only appear as a pending code and will go aways after a few drives.

• I have new OEM Bosch spark plugs for this engine in and a new ignition coil which is OEM Delphi for less than 6.500 miles. I have also put in back my reserve ignition coil with no difference.
• I have claned the throttle body.
• I have swapped te MAP and MAF sensor whith the same one from a friends car with no difference (even thou they shoved normal readings).
• I have also put in new injection nossles for cylinder 2 and 3 and swapped the cylinder 1 and 4 injection nossles with no difference.

LTFT and STFT mostly show that the car runs a little bit on a rich fuel mix, but we are talking about + 2%, which I think is quite ok. Rarely will STFT go over + 3%, which is normal when accelerating, which is so normal. I mean, with constant steady driving it’s up to 2%. I also checked the front O2 sensor parameters, they look ok, the voltage reacting always and quickly, the catalyic converter does not look clooged. It’s the same when using 100-octane gasoline, I tried that too.

The car otherwise accelerates very nicely, either when you press it hard or light.The engine does not consume oil. It will never log pinging when going uphill or accelerating (lets say medium to high load), only on light load and in neutral. I have listened to the engine when it logged pinging. I have not heard any pinging and I was in a garage. I know that the pinging sensor hears what out ears don't. But even light pinging is hearable in my experience. Two mechanics already looked at the car and the data the ECU provides and could not find anything. Found nothing. I am out of ideas.

Thanks.

 

[redman]

Hi
Could it be the knock sensor itself at fault. I do remember they have to be tightened to a specified torque.

 

[zk_EU]

Hi, thanks.

I have thought about the knock sensor. But my mechanic told me that when it fails, the ECU has usually has no problem identifiing it that it is in fault.

Also, when I sometimes get actual pinging (which is normal for this engine and all its predecesors), the knock sensor has no problem picking it up and reducing the timing. And that pinging you can also hear if you listen to it.

That's the problem here, you can't here any pinging when it logs the pending P0300 fault. Forgot to mention that it sometimes also logs pinging on all cylinders when I step off the gas when there is no fuel input (so it probably can't misfire at that time right). It well log pinging when I start the engine and give it some revs (1.500 RPM) and I doubt there is light pinging when the mixture is rich.

I was actually thinking about te crankshaft position sensor or the camshaft position sensor may be at fault? But ther car always starts normal, idles betifully and so on.

 

[redman]

I had considered that myself as it is the only way the ecu can detect a misfire iirc. The engine ecu monitors the time it takes between each cylinder's power stroke, using the crank sensor. The crank speed slows slightly when a cylinder misses and it should be increasing or staying the same.
I have heard of the connector at the coil pack causing problems so give them a wobble while the engine is idling.
I suggested the knock sensor because I seem to remember a tsb referring to them being torqued up incorrectly from factory causing problems later on.

 

[zk_EU]

Yes, it uses both, the knock sensor and the crank sensor.

I am thinking about the crank sensor, but when I think about it, why would then show pinging at light load and not at higher load. If the sensor was bad, would it not show pinging al the time as the roation of the crancshaft at high and low load is the same at the same RPM.

The connector on the col pack is fine and is solid. I also gave it wooble and nothing happened. I also cleaned it with no difference. :/

 

[redman]

Have you loosened the knock sensor and then re-tightened it to the correct torque?

I was on the understanding that a knock sensor would not have anything to do with sensing a misfire. It senses noise/shock in the block and inputs it to the ecu, which in turn corrects ignition timing on that basis.

What octane fuel are you using? Try a higher octane if you can and see if it makes any difference.

 

[zk_EU]

Hey, thanks. I can loosen and re-tight it, but I doubt the problem is the knock sensor. But it is worth a try.

I have already tried 100-octane fuel with no difference whith this fault.

 

[redman]

Vauxhall Workshop Manuals > Astra J > Engine > Engine control and fuel system - 1.6L (LDE, LLU), 1.8L (2H0) > Repair Instructions > Knock Sensor Replacement - LDE, LXV, LUW, 2H0 and LFH

Astra J > Vauxhall Workshop Manuals > Engine > Engine control and fuel system - 1.6L (LDE, LLU), 1.8L (2H0) > Repair Instructions > Knock Sensor Replacement - LDE, LXV, LUW, 2H0 and LFH

workshop-manuals.com

I think your engine is the LDE engine.
If you get the donate window, come out of the link then back in to it.

 

[zk_EU]

Hey, thanks. I will give it a try

Thank. I know this site

 

[zk_EU]

Hey!

I haven't dealt with this fault much lately as I had enough of it last year . So I did not have time jet to jack the car up and check the knock sensor.

But I am thinking about something.

After New Year, I looked at how much knock had been detected on all the four cylinders since I last checked (more then a month ago). And it was quite a lot. On cylinders 2 and 3 there were about 45.000 register knocks on each cylinder (cylinders 1 and 4 were about 5,000). On Sunday, I also did a long highway drive which added another 1.500 detected knocks on cylinders 2 and 3. Nothing extra on cylinders 1 and 4.

My questions is just, if there was really as much knock as it is recorded/registered by the ECU, would not I have somehow feel that on acceleration ar as engine shaking, slugish performance, anything? Because other than the Service stabili track warning and a pending P0300 every now and then, the car works great. It accelerates great, constant driving is great, pulls up hills great, all highway slopes done without noticeable problems.

I did find out in the mean time, that it only detects knoc when I press the gas pedal minimally and the engine is at very light load. For example, the road descends slightly and you only have to press on the gas pedal just slightly so that the vehicle does not decelarete, etc. When the engine is at just a little more load than what I wrote, it does not detect any knocking.

 

[[email protected]]

Hey!

I haven't dealt with this fault much lately as I had enough of it last year . So I did not have time jet to jack the car up and check the knock sensor.

But I am thinking about something.

After New Year, I looked at how much knock had been detected on all the four cylinders since I last checked (more then a month ago). And it was quite a lot. On cylinders 2 and 3 there were about 45.000 register knocks on each cylinder (cylinders 1 and 4 were about 5,000). On Sunday, I also did a long highway drive which added another 1.500 detected knocks on cylinders 2 and 3. Nothing extra on cylinders 1 and 4.

My questions is just, if there was really as much knock as it is recorded/registered by the ECU, would not I have somehow feel that on acceleration ar as engine shaking, slugish performance, anything? Because other than the Service stabili track warning and a pending P0300 every now and then, the car works great. It accelerates great, constant driving is great, pulls up hills great, all highway slopes done without noticeable problems.

I did find out in the mean time, that it only detects knoc when I press the gas pedal minimally and the engine is at very light load. For example, the road descends slightly and you only have to press on the gas pedal just slightly so that the vehicle does not decelarete, etc. When the engine is at just a little more load than what I wrote, it does not detect any knocking.

HI to everyone.
I have the same problem with my Astra J - same engine. My problem is only on cylinder 1 and 4 (2 and 3 are OK ) .
Has anyone find solution for this till now?

 

[zk_EU]

Unfortenatly not. I still have this problem. Driving with it for more that 8 months now. Car has been to 5 mechanics and no one can find what the cause could be. You car works fine thou?

 

[[email protected]]

No, same problem is still there.
I have this problem since I have changed gearbox.
At first I had problem only with catalytic converter.
At same time, I wanted to do a full srevice of car.Changed catalytic converter, whole clutch, gearbox, oil cooler....
When all that was done, mechanic has a problem to start engine. After few days, he hind out that problem was with magnet ring on crankshaft. (behind flyweel)
Since than I have this errors P0300 and U0100-71, rarely - when driving on highway.

Did you changed knock sensor?