Blue smoke from exhaust

[mashriqain]

I have searched the Internet and troubling to see the following:

Blue Smoke: Blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel air mixture. As with the white smoke, just a small drop of oil leaking into the cylinder can produce blue smoke out the tailpipe. Blue smoke is more likely in older or higher mileage vehicles than newer cars with fewer miles.
How did the engine oil get inside the cylinder in the first place? The car has many seals, gaskets, and O-rings that are designed to keep the engine oil from entering the cylinder, and one of them has failed. If too much oil leaks into the cylinder and fouls the spark plug, it will cause a misfire (engine miss) in that cylinder, and the spark plug will have to be replaced or cleaned of the oil. Using thicker weight engine oil or an oil additive designed to reduce oil leaks might help reduce the amount of oil leaking into the cylinder.

The car's diesel and engine was overhauled like 4 months ago :-!, could it be due to the cold weather? I am hoping it is since it wasn't happening before...

[AhmedBaig]

a number of factors also have to be considered when evaluating the root cause of 'blue smoke' in a diesel engine.

the quality of diesel is a major constituent to be considered. abroad two variants of diesel are available to the consumer one for each season: summer/winter

try and get a compression test done on your engine if possible that would truly be a one stop solution in gauging the exact reason of the blue smoke emittance.

in order to help you further you would also need to mention: what vehicle are you referring to here? the sort/type of engine oil you are using currently for your car?

[AhmedBaig]

i must also add: mechanics in pk usually link bad piston rings etc when answering queries on blue smoke emittance issues.

the only way to gauge and catch the problem by the neck is by conducting a compression test on your cylinders.

[mashriqain]

Thanks for replying here.

It's 1996 Corolla, 2000 cc engine

[mashriqain]

i must also add: mechanics in pk usually link bad piston rings etc when answering queries on blue smoke emittance issues.

the only way to gauge and catch the problem by the neck is by conducting a compression test on your cylinders.

Who can conduct the compression test? I mean special mechanics/shops/labs?

[AhmedBaig]

type of engine oil being used? in your build did your replace the pistons/rings etc using new parts or were refurbished products used?

[mashriqain]

Caltex Delo Gold, currently it has run 800 km from the last oil change. Everything was replaced with new parts.

[AhmedBaig]

i would recommend you wait it out for an islamabad member to further guide you on the compression test venues. in my opinion i can only be certain on the pistion rings etc once a compression test has been done.

[mashriqain]

Sure - I can wait, thanks for your help so far

[vampires]

same problem with my car on petrol engine...
engine is recently overhauled.
and giving me perfect pick and power but em bit confuesd from smoke from exhaust...

[dkstinger]

Adding STP to engine oil also causes blue smoke. Do you use STP in your car?

[mashriqain]

Adding STP to engine oil also causes blue smoke. Do you use STP in your car?

No

[jz]

not sure of diesels but i know blue smoked from a petrol engine is not a good sign,means the engine is getting weak n the piston rings need to be replaced.not sure if the same logic goes for diesel engines.

[smraza01]

main reason forsuch a problum as you already researched is leackageof oil within the cylinder it could happen over a period of timeby wear and tear or rigth after an overhaul if not done properly. the only thing faulty isthe oil leakage ring at th most bottom of all the rings in the piston. can be changedeasily by a trained mechanic without even getting that engine out of the hood. in diesel engines as you know thick fuel after fractional distillation resembels more to lubricating oil base and as such can produce blue smoke when engine is cold but would get better with temperature. better use a thermostatic valve for good performance and long life of engine.

[VCheng]

Blue smoke is an indication of oil being burnt in the combustion chamber. Finding the source is not always easy in a diesel engine running on Pakistani fuel. I can give a proper diagnostic workup, but that requires tools and expertise.

However, an easier way is to try the following:

Does changing the pump change the smoke? If so consider contaminated fuel as a cause.

Is the smoke more when first starting after overnight, or in cold starts? If so, consider valve seals and valves, i.e the top end.

Is the smoke continous at all times, and does the engine consume increasing amounts of oil? If so then consider worn rings and pistons and cranskshaft assemby, i.e the bottom end.

Without looking at the engine, my guess is that the issue is going to be probably a mix of all three major causes.