"You get what you pay for" is a well known saying and applies to many industries especially in the Turbo Reconditioning world.
A Turbo Rebuild done on the "Cheap" can not only be a waste of time and money..... It can be dangerous.....VERY Dangerous.
Over the years we have seen some shocking repairs done on the cheap and to "save a few quid" This can include reusing worn and damaged compressor wheels and Turbine shafts and in some extreme cases reusing bearings and seals. Reusing ANY part that has signs of wear or damage is a waste of time. Take the Turbo compressor wheel for example. "Its only rubbed against the housing a little"........... By reusing a compressor wheel that has come into contact with the housing, the Turbocharger will now have to work harder to pump the same air as before. This is due to the excessive wheel to housing clearance. Working harder to achieve the same result will mean a drastic increase in wear and the lifespan of your unit, as well as higher air charge temperatures and oil temperatures reducing MPG and power.
A Turbo part that can be dangerous to reuse especially in Turbo Diesel applications is the front oil seal and Seal Plate. As diesel engine runs on refined oil, any oil leaking from the turbo can cause a "Run away" situation. This is where the vehicle runs on the oil leaking from the Turbo and begins to rev. The higher the engine revs, the more it sucks the oil through the Turbo. Turning the engine off will not help as you are simply stopping the fuel entering the engine, but its not the fuel the engines running on!
If you are quick (and brave) you can stop whats about to happen by either stalling the engine by choosing a high gear (5th) and with the hand brake applied and foot on the foot brake release the clutch sharply (This will only work on a manual) or the scary option............ Pop the bonnet, pull off the air filter and push clothing or similar into the air intake pipework to stop air getting into the engine. If you manage to do this we salute you as its pretty god damn scary attempting it. Otherwise, get well clear and watch as your leaking Turbo results in a engine failure or in some cases a write off of the whole car if it catches fire.
At Turbo Rebuild we:-
NEVER reuse bearings and seals
NEVER reuse a worn seal plate (infact in any rebuilds we now replace as a matter of course)
NEVER allow a Turbo to leave our workshop unless it has passed testing
ALWAYS supply vital cleaning instructions for boost pipework.
DON'T TAKE THE RISK "BECAUSE ITS CHEAP!