City 2005: Engine changed to L15A2. It knocks at high speed. Should I return it?
I recently (10 days ago) swapped the engine on my Honda City 2005. Could not find the L12A2 so put in an L15A2, which I guess came from Malaysia. Got test warranty for 1 month only.
Just after installing it, test drove for a day and then took it to Swat tour.
The engine work great. I love the extra power. Reaching 160 kph was very easy and then I saw a speed camera.
Used regular fuel from PSO.
There is only one thing that makes me raise my eyebrow. When I cruise at 120-130 kph on motorway (and get in the high speed lane) I can sense the engine knocking. Especially when accelerating. This knocking is not distinguishable at slow speeds.
So my question is, does this behaviour classify as so bad that I must return the engine or there is some solution to it? For example, tuning, use of hi-octane (I believe Malaysian L15A2 are built for petrol of 91 Octane number and regular does not fulfill that requirement), etc?