Pinking

[johnxyz]

Hi - From out of nowhere, my 2003 petrol auto non-turbo has started pinking.

Have tried various fuels, all are the same.

Anyone have a good idea what I can do to cure it, or most likely cause. It happens pulling away gently or more quickly.

thanks.john

[S24SDJ]

Vpower cured it for me.

Have you checked anything yet?

Check the timing hasnt slipped. Check the knock sensors are working and have the ability to perform timing advance. Look at vacuum hoses, inlet manifold for leaks. Check fuel filter/lines/injectors aren't blocked.

[volvo2]

I have a sound that sounds a lot like pinking but is not. Are you sure it is pinking and not the exhaust or the contents of the catalytic converter vibrating? I am pretty sure that is what I have.

[deepsix]

Not a bad list of reasons to pink(or Ping as the Merkins call it)
http://www.mikuni.com/fs-tuning_guide.html

[oragex]

Good chance the thermostat is stuck slightly open. Makes the top engine run hotter and pinging.

[johnxyz]

Lots there, thanks guys. I've not looked at anything yet, wouldn't know where to start!

Actually another strange thing is happening. Some time after I park up and switch off, the internal fan starts up. Someone said it should do that, but it didn't occur last summer. This can be half hour after I've parked up. Never had a car do that before.

Thanks again, I'll look into some of this..

[Orca2]

Fan can run at about 55 minutes after stopping to dry out aircon ,I think it is mentioned in the handbook somewhere!

[greasyfingers]

It's pretty unusual for a modern car to pink (or knock), so as others have said, do make sure you are not hearing something else. Pinking is a distinct, hard, metalic rattle, or rapid serious knocks of from the top end of the engine, usually when under load - when accellerating or going up hill, for example. You are unlikely to hear it at idle, or when off the throttle

If it is pinking, you need to address the issue quickly. Pinking is an uncontrolled explosion, or detonation, in the combustion chamber, as opposed to a progressive - though rapid - burn. It can have catastrophic consequenses; in serious cases it can quickly blow a hole in the piston.

You are unlikely to have the noise without other symptoms, though: an acrid smell to the exhaust; overheating; lack of power, extra fuel consumption.

It could be caused by a number of things: wrong or damaged spark plugs; a build-up of carbon in the chamber; the wrong fuel; the wrong mixture; an airlock or lack of coolant; bad valve timing or, most usually (before cars were controlled by computers, anyway) bad ignition timing. In a modern car, the electronics should take care of many of the parameters that cause pinking. There is also a knock sensor that will retard the ignition timing to quell it if it detects any, so if it persists despite this, it may indicate something more significant is wrong.

Really, you are going to need to get someone to diagnosed it properly, and preferably pretty soon, if you cannot do it yourself.

[johnxyz]

I'm pretty sure it is pinking, its only under acceleration.

Thanks for all the info, I'll get her checked out asap… will report back

[BarryCambs]

I had what I was sure was pinking on mine (2.4t) but assumed it couldn't be with modern engine management and decided it was a heat shield rattle or something. It only happened during hard acceleration and the car is not used hard, so I decided to ignore it. Out of devilment I filled up with V Power before a long journey. The engine definitely seemed more powerful and the pinking disappeared immediately!

I wondered if it was a knock sensor problem, but since then the car has been scanned by an independent with proper Volvo computer access and nothing came up. I had the head skimmed when the head gasket went which could have put the compression ratio up a bit, but the noise was there before that was done. If it sounds like pinking, then it could well be, but if V power doesn't help it sees strange?