yes thanks to onlyfaith for clarification.
I would never advise baleno owners to water wash the engine,but if you use engine cleaners,they are pretty effective as i personally use them with out any issue.
Now the issue we were discussing.Your car's engine is a sealed container of controlled explosions. The engine requires air for combustion process, drawing it in through an air filter. Sometimes extra air enters into the system through a not firmly tight air filter hosing,generally it a sort of vaccum leaks. Vacuum leaks upset the air-to-fuel ratio and can cause air fuel ratio go lean,resulting in misfire, poor engine performance and changes in fuel economy.
On the other hand EGT (exhaust gas temp) gets affected with the lean air fuel ratio,that is the volume of air coming into the cylinder compared to the volume of fuel. A very lean mixture, that of too much air combining with a small amount of fuel, will cause the EGT to soar which is critical for the engine in long run.
Notice if engine idles at higer rpm than normal,this might be the reason.
To check whether engine is taking enough air from around filter box,keep tissue papers hanging all around the filter box,start the car,give it revs from the accelerator wire attached with throttle body,notice any movement of tissue papers around the filter box due to acceleration,filter box will suck air inward from its loose points.(desi test method)
i too am running my own car with damaged clips on air filter hosing,not getting the time to source a new.So that seems to me my personal problem:D