Jump to content
Do Not Sell My Personal Information


Pinking


Paulas
 Share

Recommended Posts

I have a year 2000 1.8VVTi with a pinking problem. The pinking is most noticable when I am gently accelerating on the flat or putting a bit more juice in when I'm going up hill. It seems to be in any gear at any speed. I have had an engine management (mixture too lean) issue that is still unresolved but during investigations I've had the air flow sensor cleaned which made a big improvement in the pinking and the lamda sensor on bank 2 replaced with no improvement.

Is there something else I can do? The garage want to change the ECU next but with no guarantee that it will cure anything.

Any help or suggestions would be gratefully received.

Link to comment
Share on other sites


I have a year 2000 1.8VVTi with a pinking problem. The pinking is most noticable when I am gently accelerating on the flat or putting a bit more juice in when I'm going up hill. It seems to be in any gear at any speed. I have had an engine management (mixture too lean) issue that is still unresolved but during investigations I've had the air flow sensor cleaned which made a big improvement in the pinking and the lamda sensor on bank 2 replaced with no improvement.

Is there something else I can do? The garage want to change the ECU next but with no guarantee that it will cure anything.

Any help or suggestions would be gratefully received.

An engine gets power by burning fuel and air. The expanding hot gasses apply pressure to the piston and provide the force to move the piston and hence the car. Pinking or pre-detination is where the mixture explodes. The shockwave passes through the combustion chamber and impacts on the piston, head and cylinder creating the pinking noise (and also causing damage to the piston mostly since it's the softest and lightest component.

Causes are a combination of temperature and pressure. As the flame front propogates through the chamber temperature and pressure build ahead of it till the remaining mixture explodes.

This could be your mixture problem (leaner mixtures tend to burn hotter since they're oxygen rich). Oil getting into the chamber can cause it too (slower burn). The knock sensor should !Removed! the ignition timing to reduce the combustion chamber pressure to prevent this. For some reason it doesn't sound like it is. If there is a problem this maybe that the mapping in the ECU won't allow it to !Removed! far enough or it could be a problem with the knock sensor itself.

It could be a mixture fault being caused by a sensor, a sticking injector, worn engine allowing Oil into the chamber (what's your Oil consumption like?) or driving style (labouring the engine too much)

Sorry I can't be more exact without a good look at the engine

Link to comment
Share on other sites

Thanks for comments guys.

I am using about 1 litre of Oil per 3000 miles at the moment.

The car has done 63000 miles

I did try some decoking additive in the pertrol but it didn't make much difference.

Does the "quality" of petrol make a difference? If I used Shell Optimax would it improve things?

Is there a way of checking the Knock sensor?

I don't tend to labour the engine but then again I don't like revving it hard either. Usual rev range is 2000 to 4000 rpm. The pinking does seem to stop if I put my foot down hard.

Link to comment
Share on other sites


Paulas,

Have you had your fuel pressure measured? If not get this done first.

If you were to replace anything, I would try replacing the ignition coils before changing the ECU. I understand that the 1ZZ-FE has individual coils for each plugs so it is not possible to monitor the spark line to determine like you do with cars with HT leads but I am sure it works out cheaper than replacing the ECU.

Faulty coils can lead to mixture being too lean as it doesn't burn properly and engine will lean it to compensate.

Link to comment
Share on other sites

Easy way to check the knocking sensor: take a hammer and knock on the block with it... The engine should start coughing! As soon as you stop knocking the coughing should stop as well.

Link to comment
Share on other sites

Knock sensor is just a vibration sensor tuned to the shape of the engine. Knock causes a specific frequency because of the shape of the block. When the vibrations get above a threshhold level the knock sensor detects it and the ECU retards ignition timing to lower cylinder pressure.

Never tried it but I guess hammering on the block sets up a frequency similar to the pinking and confuses the ECU.

It does have individul ignition coils. If you take off the plastic head cover you can see them in the trough of the head cover. Don't quite understand how a faulty coil would lean off the mixture though. Faulty Injector maybe. A faulty ignitor would cause misfire problems but I don't think it would fool the ECU into leaning up the mixture

Link to comment
Share on other sites


Black Knight,

Faulty coil can lead to lean mixture. Becuase, initially when the uneven combustion occurs on the cylinder(s) with faulty coil, O2 sensor will detect as being too rich, so it then adjusts the mixture to go lean.

Coils are a funny commodity. Resistance can be OK but it could be still faulty. In some cases, it also plays trick according to temperature - i.e. symptom apparant when the engine warms up not noticable when cold etc. As it appears that Paulas have tried everything, I thought it would be best to try the coils.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...




Forums


News


Membership