Knocking issue in Xcent CNG: Local garage says need to open engine head

It is difficult to trust people for such critical parts and find FNGs that take an interest in these slightly older cars.

BHPian Nissan1180 recently shared this with other enthusiasts.

I’d like to share a note about the fate of our 2015 Hyundai Xcent CNG. It has run for 125000 km and the knocking issue has returned. The local garage that the car goes in for servicing diagnoses it to be an issue with the engine head and it has to be opened up.

Taxis run on CNG for over 200000 km. Our car suffered this fate, perhaps, because we never monitored the oil and coolant quality and trusted third-party opinions from “experts” at different FNGs who said that the oil was okay based on Color. Apart from this, I don’t know why this would happen. The car runs alright on petrol but there’s heavy knocking.

One more issue is that the rear suspension needs attention as the left tire has uneven wear.

It is difficult to find FNGs who take an interest in these slightly older cars. It is difficult to trust people for critical parts like the engine head. Right now I’m driving on petrol but eventually, the problem will occur with petrol as well.

I have two questions:

1. Is it possible to replace the head with a company part without any lathe or machining work?
2. Will the car remain reliable after this work is done?

This message is a request to all owners especially those who use CNG to always check oil and coolant quality and replace it irrespective of whether the garage suggests or not. The few hundreds that the garage guys saved on oil changes can lead to a costly engine rebuild.

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