Do cars still suffer from 'pre ignition'?

[wild_one]

My 2005 1.6 vct engine focus is a little poorly, Symptoms are random lumpy idle, and pre ignition/rattling when put under load in a high gear. No EML, but a scan shows pending codes P0172 and P0175. Short term fuel trims are  pretty normal and long term are around -10%, O2 sensors also look to be functioning normally. I have checked the vacpipe that runs from the inlet manifold to the PCV, and the valve itself. Is that the only vac connection?

Any help would be appreciated.

[Botus]

many modern cars have knock sensors, they wind back the spark to reduce uncontrolled burning.  no idea if a basic old car like the 1.6 has it

what quality is the fuel? condition of the plugs and the compression of the engine?

[michaelburrows]

I have a 2.0 tdci 2013 and it also pinks. Not all the time. Only in 6th gear usually on motorway under a bit of pressure. Don't know y.  It pisses me off. I usually take my foot off the accelerator a bit

[isetta]

as an experiment I would try the more expensive premium fuel to see if that stops it.  I have not had a car pinking for years.  one of the factors in the past that could cause it was a build up of carbon in the combustion chamber that would glow red hot and ignite the compressed fuel/air mixture before the spark plug sparked.  you don't hear of the need for a decoke these days. 

[wild_one]

I'm confused because the codes indicate rich condition, but 'pinking' is usually associated with 'lean'?

9 hours ago, isetta said:

as an experiment I would try the more expensive premium fuel to see if that stops it.  I have not had a car pinking for years.  one of the factors in the past that could cause it was a build up of carbon in the combustion chamber that would glow red hot and ignite the compressed fuel/air mixture before the spark plug sparked.  you don't hear of the need for a decoke these days. 

thats very true, I suspect that has a lot to go with use of unleaded fuel though. I have driven many petrol focus, and many of them could be made to pink. I wonder if it's a byproduct of cars designed to run as lean as possible for economy reasons