Question : MY five-year-old Naza Ria had been overhauled due to overheating caused by radiator fan failure.
The cylinder head/block was skimmed at the same time.
It had been three months since the overhaul and I had gone over 10,000km.
The longest distance travelled since the overhaul was from Kuala Lumpur to Port Dickson.
The temperature indicator is normal.
Since the overhaul, the coolant or water in the expansion tank drops to between the Full and Low mark.
I have to top up to the Full mark every week.
The service centre had confirmed that there is no water leaking into
the engine as the engine oil is normal with no mixture of water but does not offer any solution.
1. What could cause the water to disappear as there is no leak in the piping?
2. I had been advised to change the radiator cap to a higher rating (presently using 0.9 psi) as the engine block had been skimmed. Do you think it is all right and that it will not burst the radiator hoses/ pipes?
3. Is there any solution to reduce water consumption, for example adding "anti-leak" additives to the
Coolant does not simply disappear!
If it is not mixing with the oil, then it is going out through the exhaust
In that case, one needs to look carefully at the cylinder head as it may have an internal crack which is letting water into the combustion chamber which then goes out with the exhaust gases.
If the overhaul was due to overheating, the obvious job that should have been done by the workshop would have been to crack test the cylinder head, which I think was not done.
You may end up having to take the head off again for that to be done.
Regarding skimming the engine block, be sure that the mechanic knows what he is doing.
The Ria uses wet cylinder liners and if re-assembly is not done correctly, you can end up with even bigger problems.