Hi all my 98 cinquecento 900cc pinks. Not badly but I don't like it! I've checked for vacuum leaks etc can't find any. Had to replace rocker cover gasket yesterday so went through all the pipes etc all where good. Otherwise the engine runs very well. It only pinks under load on long hills etc. I've always worked on cars with a distributor and a vacuum advance. But these don't even have a knock sensor in the block to retard ignition. This has been going on for ages now ( i just drive it and back off the throttle till it stops)and there are no fault codes.the engine is 100% unmodified. I gave it a full service in march and everything looked as it should. I did have to change the HG about 70k miles ago but did not skim the head and I used a Payen gasket as I've always liked them it runs best using a higher octane fuel. Any way any body got any ideas? Its got me beat! Oh she's done over 100k miles hardly uses any oil and I hardly ever need to top up the coolant. Also using NGK bpr6es plugs. Thanks guys..nick the forum newbie

I was going to suggest using 98/99RON Petrol, but I see you are doing that already.

Mine also pinks under load on 95RON, but is fine on 99RON, so I use that.
It is probably the ignition timing advanced slightly.

David C said:

I was going to suggest using 98/99RON Petrol, but I see you are doing that already.

Mine also pinks under load on 95RON, but is fine on 99RON, so I use that.
It is probably the ignition timing advanced slightly.

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Thanks for your reply after talking with guy who used to run a mobile tune up service his opinion is that modern petrol is crap! My car didn't pink 7 years ago. So either he has a point or as the engine ages things change.

The ignition timing is adjustable, but as mine is fine on 99RON I've left it alone.

Yours may need a tweak.