White smoke from exhaust

1992 Honda Ascot Innova, 163000 Kms. For some time now, I have been noticing white smoke coming out of the exhaust when the car accelerates from rest and sometimes when reversing. I don't think this smoke is dew evaporating as the smoke also occurs when the engine has warmed up. Sometimes there is a lot of white smoke as I can see it in the rear mirror. However, don't see the smoke (in the rear mirror) when car is at normal speed (50 Km/hr). Could the coolant be leaking into the cylinder, hence, problem with the cylinder head gasket? Have not yet checked the engine oil for mix-up of oil and coolant. We recently replaced many pipes due to coolant leaking from them.
Also, the engine sounds as if it is under a lot of pressure when the car is going up hill and has not picked up enough speed.
Would really appreciate suggestions as to what could be wrong. Thank you.

if the smoke dissapear pretty easy.. then its water, if not then its oil ...

How it smell?

how its your oil level?

But, I thought that white smoke was caused by the burning of water/coolant. Or am I wrong here.