Pinging Under Load

With that kind of mileage, I would suspect carbon buildup in the cylinders. Then again, it could be a timing issue. It could also be spark plug related. When was the last time you changed your plugs?

Hi there..

Plugs were changed about 5k ago and the old ones were good colour. Timing is good as well but I was wondering if this could be an anit-knock sensor or something to do with the cam position sensor? Would this prevent timing from being advanced etc?

Steve

This vehicle is equipped with a knock sensor. If it does not operate properly and the computer does not discover this, it may overadvance the timing.

You should be using 87 Octane fuel or better. Lower than that can cause spark knock.

Anything that will increase combustion chamber temperatures or compression (including carbon build-up) can cause spark knock.

Hi Hyundaitech,

Thanks for the response. We've been using 91 octane for the last couple of years now and that cured the problem then but it's quite noticeable now. There are no codes set in the computer (just read it) and is starts fine. Any way to check the knock sensor?

Steve

Ironically, that may have contributed to the problem. If you use 91 octane fuel in an engine designed for 87 octane, it doesn't burn efficiently and leaves more deposits in the engine.

You could try tapping on the block near the sensor with a wrench or something and check with a voltmeter to see if it gives a signal.