2 - Stuck PCV Valve

If Blue Smoke appears all the time your engine is running then the first thing to check is the PCV (Positive Crankcase Ventilation) Valve. If pressure builds up in the Oil Pan, the PCV Valve allows this pressure to release. The pressure is released into the Intake Manifold where the Engine gets its air for working. If the PCV Valve gets stuck open then it will keep mixing the air with oil and other gases from inside the engine. The oil gets mixed with the Gasoline and Air and gets burnt creating the Blue Smoke.

PCV valves are expected to be replaced at least every two years / 30,000 miles if not more often.

With a stuck PCV Valve, the throttle body and intake manifold will end up covered with oil.

Fix PCV Valve

This should be a simple fix and cheap as well. Look for a tube that connects to the Intake Manifold. Follow the tube back until you find your PCV Valve. Remove the PCV Valve from the tube and replace with new one.

3 - Worn Engine

If Blue Smoke from the Exhaust appears all the time your engine is running then your engine is probably worn if it is not the Valve Seals or the PCV Valve. Pistons inside the engine move up and down a cylinder. These Pistons have metal rings like bracelets round the side of them. These rings help the piston form a tight seal against the cylinder. When the cylinder and or rings get worn, oil from beneath the piston can come up. The oil gets mixed with the Gasoline and Air and gets burnt creating the Blue Smoke.

Mechanics can check to see if the engine is worn. They remove the spark plug on each cylinder of the engine. Then they screw in a machine that measures compression (compression tester) into each spark plug hole (usually one cylinder at a time). The engine is then turned over on the starter. It will not start as there are no Spark Plugs. The compression tester shows the Mechanic how much compression each cylinder gets. Numbers from the compression tester can be checked against the normal numbers for that engine. If a number is lower than normal for a cylinder then that cylinder is probably worn.

Fix Worn Engine

You can buy liquids that will attempt to fill in the worn parts of the engine. The liquids are usually added with the oil. Sometimes they work and other times they do not.

Fixing a Worn Engine is beyond the average person. Usually most people buy a replacement engine and have it installed. Cost for this job in the USA as of 2010 is around $2,000 and up depending on make, model of vehicle.

4 - Blown Turbo

When you car has a Blown Turbo, Blue Smoke appears in a big cloud behind you suddenly. A Blown Turbo is either a failed oil seal in the Turbo or the Turbo casing has broken. In both cases they are now letting oil into the intake of the engine. It is this oil getting into the engine that causes the Blue Smoke from the Exhaust.

Fix Blown Turbo

When the Turbo Blows it is not a good idea to drive the car with the Blown Turbo. This is because the lack of oil in the Turbo will create bits of metal. The bits of metal will get in the engine. The engine will be damaged by the bits of metal.

Before fixing the turbo you need to determine what damage the Blown Turbo did. If the inside of the Blown Turbo did not break into little pieces then you may be ok. In this case you can either rebuild it or replace it. If the inside of the Blown Turbo did break into pieces then you might have engine damage. A mechanic should look at the engine before money is spent on the Turbo.

5 - Blue Smoke with loss of Transmission Fluid

Older cars/trucks with vacuum controlled automatic transmissions use a modulator to control the transmission shift. The modulator uses engine vacuum to control it. If the diaphragm or another part of the modulator fails, it allows the engine to suck in transmission fluid. Transmission fluid sucked in by the engine then gets burnt like oil causing the blue smoke out the exhaust.

Fix Transmission Modulator

Locate the transmission modulator, remove and replace with new one. The vacuum line to the transmission modulator may also need replaced if damaged by the transmission fluid.