Smokey tailpipe after every oil change

**Archerfish** · July 12th, 2018 09:27 AM

Originally Posted by Jiggs

Sir if you can share...what is wrong with the practice? What particular part ng engine potential na masira kapag ginagawa lagi yun? Thanks..

From what I understand, using compressed air has the tendency to introduce water inside the engine. The presence of water inside the engine is not good, either with fuel oil or lubricating oil.

Since this ordinary compressor is not equipped with an air dryer, those "small water droplets" (water mist) will enter the engine. You can verify the presence of water by draining the compressor tank.

**jick.cejoco** · July 12th, 2018 12:11 PM

Originally Posted by Archerfish

From what I understand, using compressed air has the tendency to introduce water inside the engine. The presence of water inside the engine is not good, either with fuel oil or lubricating oil.

Since this ordinary compressor is not equipped with an air dryer, those "small water droplets" (water mist) will enter the engine. You can verify the presence of water by draining the compressor tank.

That is not a valid enough reason.
As the engine cools down, the crankcase goes into a partial vacuum and sucks moisture laden air into the crankcase. This moisture is then introduced into the oil and is removed by the PCV vlave when the engine runs preventing acid formation in mineral based motor oil( mineral oil has sulfur combined with hyydrogen in the moisture resulting in H2SO4).
The moisture in the crankcase is not of a concern since we do not live in moisture free environment.

The concern of pressurizing the crankcase with moisture laden air is the potential of creating new oil leaks in marginal to deteriorating gaskets, seals and the half moon plugs od the cylinder head of over head cam engines.

**Jiggs** · July 12th, 2018 04:38 PM

Ok...Thanks so it was for the potential over pressurization of old seals...well been having that practice na for decades na sa lahat ng mga naging cars ko and never naman ako nagkaron ng bad experience...I just make sure na slight air purge lang with a very clean rug on it's nozzle to trap any moisture/particulate contaminants sa compressed air. Na observe ko kase na it's about 1-1.5 cup full pa ang na drain using that method. And imagine kapag you use a flushing oil then that amount will be part of the new engine oil which we all knew na Oil Flush is not a good mix with oil for normal use. Practice ko is una sa dipstick air purge then sa main oil cap.