Disappearing engine oil
Question : I OWN a 2002 Proton Iswara
1.5 which has clocked 159.000km.
Bout a month back, my timing belt snapped and I sent it for a top overhaul.
The entire valves, seals and others were changed due to the breakdown.
Now the engine is running like new and purring like a cat.
However, the lubricating oil seems to be gradually missing.
I only found this out when the indicator light came on and got a big shock
when the dipstick was dry without a single drop of oil.
There is no leak under the engine and no white smoke going out through the
exhaust whether in the morning or in the day.
My mechanic reopened the engine and replaced with a new set of seals but the
problem still persists.
He can't detect where the problem is with the disappearing black oil
The other suggestion from the mechanic is to replace the engine block.
The mechanic says that perhaps my engine block was damaged during the
breakdown and this could be the reason of the disappearing oil.
Answer : You mention that after the breakdown, you only did a top
I have a feeling that your piston rings may have been damaged in the
breakdown or even a couple of rings may have broken.
I am sure that the valves hit the tops of the pistons and I am surprised that
the mechanic did not check the pistons and rings.
What you are probably having is what is called "blow-by" where the
lubricating oil is being drawn into the upper part of the cylinders when the
piston is on the intake stroke and burning with the fuel.
Normally, you would not see any white smoke at a constant throttle opening
but if you are driving at speed and release the throttle, and then accelerate
briskly, you would see a puff of white smoke, indicating "blow-by".
I do not think the block is damaged because if there is a crack in the block,
you would see oil in the coolant or vice versa and the engine may not be
"purring like a cat".
I think the best way is to strip down the engine and check the pistons and
You may then have to do a rebore and fit larger sized pistons and rings.