Hello Scotty,
I'm an avid watcher of your channel, and i love your videos.
I own a 2006 ford focus, 2.0 Litter engine, in Canada 176,000 kms on it (about 110,000 miles). I keep hearing this knocking noise (pinging) whenever I start to accelerate the car.especially audible when the engine is hot and the car is stopped at a traffic light, for example, and you start acceleration ( especially audible if you start acceleration from a stand still to go uphill).
I replaced spark plugs, the noise went away for a while and then came back.
oil level is good, I change oil religiously at 4000kms.
I thought i should try premium gas, as it burns slower. problem was fixed for a while and then came back. used engine flush by Kleen-flo, but didn't do anything!!
I even took it to the dealership, where they had a mechanic telling me it pinging. to fix it, he might retard the ignition, however he said it will screw up fuel economy!
the problem only happens in the summer months. in the cold winter months, runs perfectly fine.
I love my car and I baby it!
at the end of my tether,
please advise.
thanks in advance.

No. 1-1

just normal wear on a focus that old will do that, and your mechanic told the truth, he could retard ignition but it would run poorer and also put out more emissions. Realize in the winter, your gas in Canada (I went to university in Toronto) has a different formulation and that's why it stops in the winter. It won't hurt anything leaving it.