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TURBO

What is the turbo charger?

If you think it's broken...

Most important thing to do is to check turbo charger before take it off from the engine. Most of the time, there is no problem in the turbo charger and find it difficult to assess the problem after you take off the turbo charger.
It's usually much easier to find out the problem if you think the turbo charger have a no problem.

Please be careful to check the list 1 to 3 below. You should not think the problem is from the turbo charger at first.

White smoke (Oil leakage)

If the oil doesn't flow back to oil pan and cause a leakage, the white smoke from the muffler will come out.

I.The rise of the pressure in the engine(crank case)
The center housing of the turbo charger is in a negative pressure to prevent from the oil to leak. However the blowby-gas that occurs by the piston ring because of the friction and not proper exhaust of the blowby gas cause the oil leakage from the turbo when it's a high pressure in the crank case.
And also the oil used in the turbo does not flow back smoothly to the oil pan will cause a oil leakage.

Simple Inspection Method
(1) The white smoke will go away if you take off the oil exit, level gauge and blowby hose.
(2) When idling and open the oil-feeding hole and see if the air doesn't go in(you can check with smoke near the hole).

If there is the situation of (1) or (2) it could probably mean the pressure of the crank case of the engine gets too high. If the engine is normal, it will intake to the blowby to the engine by using the negative pressure in the crank case of negative pressure and the pressure in the turbo is also negative pressure, so the oil will not blow out of the turbo.

Conceivable cause

(1) The friction of the piston ring, cylinder and valve guide.
Can intake the blowby gas because of the galling, combustion gas leakage. The vehicles with long distance of driving must be cautious.

(2) Blowby gas or PCV valve clog or defection.
The blowby gas doesn't inhaled properly because of the hose or the head cover of the connection part clogged or the defect of the PCV valve that doesn't boost in the crank case.

(3) Blowby hose is wide open or oil catch tank is defect.
You should be careful not to wide open the blowby hose. It could not flow properly in the oil catch tank of the blowby gas because of the length or curve of the hose.

* 1. PCV (Positive Crankcase Ventilation) Valve
PCV valve inhales blowby gasin an idling and also work as a orifice to control the too much inhale of the blowby gas by engine brake or too high negative pressure of surge tank.
Moreover, if the surgr tank get to be the normal pressure by the boost, the crank case pressure lower by flowing by the PCV valve as clack valve and close it to release the gas from main to the crank case.

Confirm the PCV movement
Check the PCV flow the air into the one direction

・Clean with brake cleaner
・Change if it doesn't work after the cleaning

Make sure the the hole is clear for the blowby hose installation partof air cleaner side
The back of the connector of hose is sometimes closed with sludge.

・Confirm the hole with wire
・If it's clogged, open with wire of air blow

Make sure the PCV connector is clear
As you can see in the picture left, sometimes the hole is clogged with sludge

・Confirm the hole with wire
・If it's clogged, open with wire of air blow

II. Clogging, curving and collapsing of the oil return (drain)
It will have oil leakage because the oil in the turbo that doesn't return to the oil pan. Also the sludge in the exhaust manifold and wastegate will cause the not a smooth oil flow.

III. Excessive oil supply
Make sure to be φ0.6~1.5m for oil supply line of orifice to control the oil supply. The size of the orifice different from the engine type and turbo type. Set the oil pressure for maximum of under 2.5kgf/cm2 of turbo entrance with the orifice if it's ball bearing type.(minimum of more than 0.7kgf/cm2). The oil volume of the dress hose exit is 800cc/min.

IV. Excessive Engine oil supply
This will not have smooth oil flow to the oil pan and will have oil leakage, too. For a sudden stop or inclined driving might cause the high oil level and defective in oil return.

V. The oil will be sucked into the intake side because of the clogged air cleaner.
It doesn't cause as the problem because the tuning car usually uses stick out type air cleaner. But if it's blowby gas suction, be careful not to mistake with the oil.

VI. The oil will be sucked out to the exhausting side for the big front pipe & catalyzer-less.
Need to be careful because sometimes the tuning car has a big front pipe and catalyzer-less. Usually, it smells very strong of burning smell of oil with white smoke when the oil leakage occurs in the exhaust part.

VII. The mistake of the oil left over from the past.
Sometimes the oil leakage happen before in the intercooler or muffler could be mistaken for the oil leakage.

Turbo charger structure is sealing the oil by rotating. Therefore when the lower RPM such as idling has higher possibility of oil leakage and also once it started to leak there will be a drain that keep the oil to drift. We don't recommend for a long idling. If there is no problem from I to VII, it could be the engine problem. Please check the engine. And if there is no problem in the engine, please check the turbo charger.

No power (the boost doesn't go up)

I. Boost pressure loss (turbo charger, intercooler, throttle and intake manifold)
It could be the air leak from the joint hose between the pipes or it open by too much of the stock or other maker's boost pressure. There could be leakage from the surge tank or intake manifold.

II. Blocked or crushed part of the intake system
If the air cleaner is blocked or the rubber hose used for suction in front of the turbo charger could cause to crush for the negative pressure by the boost. And also there could be waste between the turbo charger, intercooler and throttle.

III. Throttle valve
It can't have the boost pressure if the throttle valve is fully open in some reason.

IV. Malfunction of the swing valve or wastegate valve.
Boost pressure will not go up if the swing valve of the boost pressure control or wastegate valve is open too much. The seizure of the valve, defect actuator that is to activate the valve and defect in the air pressure control for the actuator. Also check the movement of stock boost control solenoid valve and the area the hose is. And check if there is an orifice or not. Another case, even the actuator or the wastegate is working fine, if the spring is weak, it will not have the boost up because the valve open for exhaust pressure.

V. Blocked exhaust system
If there is block for the Exhaust manifold, turbo charger, extension, front pipe, catalyzer, and muffler the boost pressure will not go up.

VI. The leakage in the exhaust system
If there is gas leakage for the exhaust manifold or turbo installed flange, the boost pressure will not go up. You will probably notice when this happen because of the leaking air sound.

If you don't find any problem of I to VI, it could be the problem of engine. If you find no problem in the engine, please check the turbo charger.

Strange Noise

I. Boost pressure loss (turbo charger, intercooler, throttle and intake manifold)
It could be the air leak from the joint hose between the pipes or it open by too much of the stock or other maker's boost pressure. There could be leakage from the surge tank or intake manifold.

II. Blocked or crushed part of the intake system
If the air cleaner is blocked or the rubber hose used for suction in front of the turbo charger could cause to crush for the negative pressure by the boost. And also there could be waste between the turbo charger, intercooler and throttle.

III.Blocked exhaust system
If there is block for the Exhaust manifold, turbo charger, extension, front pipe, catalyzer, and muffler the boost pressure will not go up.

IV.The leakage in the exhaust system
If there is gas leakage for the exhaust manifold or turbo installed flange, the boost pressure will not go up. You will probably notice when this happen because of the leaking air sound.You will hear the big blow sound when it starts to open if the wastegate exit is deformed or fully open.

V. Strange noise of the pipe

If you don't find any problem of I to V, it could be the problem of engine. If you find no problem in the engine, please check the turbo charger.

Checking the turbo charger

If you don't find any problem in the engine, check the turbo charger.

Checking the vehicle

Take out the intake pipe of the turbo charger and turn the rotor with your finger. Be careful not to turn the engine on.

I. If the rotor turns:
Wheel could be broken. The compressor wheel or turbine wheel is deformed or broken. Sometimes you can see it without taking off the turbo charger, but sometimes you can't see it if you take off the housing. If it's deformed or damaged, you can hear a weird sound. If you keep this for a long time, wheel and housing will interfere because of unbalance and finally the turbo charger will break down. So if you hear the sound of a weird sound, take the turbo charger and have a check. Also if the bearing is turning in friction, the rotor is not properly moving. For both conditions, you need to take it off and have an inspection.

II. If the rotor is not turning:
The turbo charger rotor is stuck or interfering. The rotor will have lock or malfunction of turning by the seizure the ball bearing. Also the long term oil leakage occurs, it will get carbon because of the heat of the turbine and cause the rotation malfunction by the turbine and the rotor. There a case where the some waste stuck in the turbine and housing or shroud that causes the lock. In this case, you can confirm with your finger and don't have to take off the turbo charger. However turbo charger is broken so take it off and have an inspection.

Taking off the turbo charger for checking

When taking off the turbo charger, be careful to confirm the list below as carefully checking where the problem is.

I. Check the unusual bolts, nuts and hose.
II. Check for contaminant (usually caused for turbo charger damage)
III. Check for Heat discoloration
IV. Check for oil or coolant water for leakage or bad contamination

If you notice above matter, don't disassemble and bring the turbo charger to the shop where you purchased

Cause of the turbo charger failure

Failure in the oil supply (dirt, dust, insufficient oil or breakage of oil film)

If a dirt goes into the turbo charger, it will be a clearance failure and will damage the shaft receiver and bearing surface. Also there is a orifice from φ0.6 to 1.5 in the turbo charger oil supply line. In this orifice will have a dirt or sludge stuck into and have the oil film breakage and seizure.

These are the cause of the dirt get into the oil:

  • Degradation of the oil (sludge)
  • Degradation, damage or oil filter stuck
  • Malfunction of the oil filter bypass valve
  • A dirt mixed in at oil change
  • Metallic fragment or broken piece at the engine breakage (When engine blow occurs please overhaul the turbo charger)
  • When using liquid packing or seal tape, part of them could get in the oil line while turbo charger change.

Cause of the oil film breakage:

  • Degradation of the oil
  • Insufficient oil
  • Sudden acceleration when there is not enough oil in the turbo charger
  • Low oil pressure because of the oil pump defect
  • clogging of oil strainer

And etc.

Object threw into the wheel

The wheel blade will be damaged if the an object go into the intake or exhaust wheel. And if you keep drive in that condition, the shaft will be broken because of the unbalance rotor which cause bearing seizure.
The cause of the object fly into the intake system

  • The nut that tighten the impeller that's in the air cleaner or suction pipe will sucked in.
  • Assembled while some object are still there like washer or waste.

If an object is something hard like a nut or a rock, the blade will be wrecked or cut. Or if the object is soft the blade will be deformed to the back. If it's sand or dust, the blade will be wore out.
The cause of the object going into the exhaust side.

  • The piece of engine parts(plug, piston, ring, etc.)
  • Things that forgot to clean.

The lock could also happen by something get stuck from the engine to turbine blade and housing or shroud.
If something go into the exhaust side, the engine could be damaged. In this case you need to inspect the engine first.

Exhaust temperature excess

Sometimes while driving or right after you stop a car, the turbo charger can get damaged by the high heat. If you stop a car after driving, the lubricant and coolant oil also stops. This will cause the oil film breakage of the still running shaft and bearing and also the high heat of the turbine housing will transfer to center housing which cause the sludge.(heat soak back) If this sludge increase, the oil passage will get narrow and cause an even higher heat. Later, the sludge will get granular carbon and damage the bearing, seizure of the bearing and breaking the shaft. It's better to have an idling time after a drive. And if you can't have an idling like at a race, making the cooling system for center housing will prevent this problem.
If the temperature of the exhaust is too high while driving, there could be interfere between turbine housing and turbine wheel because of the deformation. Also it could cause a crack of the turbine housing and carbonized of oil. When setting please check the fuel-air ratio and also the exhaust temp.
Causes of the temperature rise:

  • Unusual A/F
  • Unusual ignition timing
  • Exhaust system clogged
  • Unusual engine management system including the stock ECU