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Was this a dealer new part or a used take off? Use diagnostics measuring blocks to find out what the turbo is doing since you can't look inside it.
 

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For that kind of money, investing in your own VW compatible diagnostics and learning to use it is a small extra price to pay? You haven't said why you replaced it and again with some fault exceptions like oil seal leaks and bearings, diagnostics can give a lot of performance information before you even start with the wrench.

If you took your car to a competent shop for repair, that's what they would do with all the diagnostics software and other tools available to them. Buying a part and bolting it on yourself, you won't know what's going on without measurements or if there was an ancilliary part involved which you missed, didn't check at the time, or accidentally damaged?

I'd bet it's not the turbo? When you buy an expensive OE part from a dealer, once you open the package it's yours with no returns. Ensuring the replacement part numbers are correct is always a risk you take. Since you've been working on the manifolds, there are other components to be careful with. I always read the shop manual first, because there are often traps to fall into with seemingly straight forward tasks.

Measure your turbo with diagnostics and come back with some results or faults if any are shown?
 

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Discussion Starter · #5 ·
For that kind of money, investing in your own VW compatible diagnostics and learning to use it is a small extra price to pay? You haven't said why you replaced it and again with some fault exceptions like oil seal leaks and bearings, diagnostics can give a lot of performance information before you even start with the wrench.

If you took your car to a competent shop for repair, that's what they would do with all the diagnostics software and other tools available to them. Buying a part and bolting it on yourself, you won't know what's going on without measurements or if there was an ancilliary part involved which you missed, didn't check at the time, or accidentally damaged?

I'd bet it's not the turbo? When you buy an expensive OE part from a dealer, once you open the package it's yours with no returns. Ensuring the replacement part numbers are correct is always a risk you take. Since you've been working on the manifolds, there are other components to be careful with. I always read the shop manual first, because there are often traps to fall into with seemingly straight forward tasks.

Measure your turbo with diagnostics and come back with some results or faults if any are shown?
Sorry. I guess I should’ve started with that. I took it to a shop because it was burning a quart of oil a week. The turbo tubes were full of oil. I didn’t complete the work myself. I asked him about the performance and he said it’s a factory turbo and there’s no adjustments for it. I’d have to buy an adjustable waste gate if I want to up the performance.
 

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Most here will assume a stock setup with no tuning tweaks because you can't ask for help if any tuning mods were done before. Even diagnostics and out of range errors it may give only relate to what V.W software expects from a standard factory setup. If you think your performance before came from tuning tweaks and waste gate (i.e boost) changes, then you need help from a tuning specialist. You should be able to tell looking at the old parts if anything has been replaced for something else. In fact, do you know if your car is stock or has been tuned? Diagnostics measurements will tell you if the waste gate is working correctly and limits at the V.W spec. boost pressure.

I've done some recent work on a V.W turbo diesel. The turbo principles are the same. Many will condemn their expensive turbo for suspected oil leaks past seals. This isn't always the case although high mileage makes it more likely. The turbo oil return to the crank case could be blocked, or there's excessive crank case back pressure due to a failed PCV or blown engine. Lift the oil cap on idle, if there's lots of positive pressure blow back on idle, that's the first issue to look at. If somebody has overtuned your engine it might have suffered?
 

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Discussion Starter · #7 ·
Most here will assume a stock setup with no tuning tweaks because you can't ask for help if any tuning mods were done before. Even diagnostics and out of range errors it may give only relate to what V.W software expects from a standard factory setup. If you think your performance before came from tuning tweaks and waste gate (i.e boost) changes, then you need help from a tuning specialist. You should be able to tell looking at the old parts if anything has been replaced for something else. In fact, do you know if your car is stock or has been tuned? Diagnostics measurements will tell you if the waste gate is working correctly and limits at the V.W spec. boost pressure.

I've done some recent work on a V.W turbo diesel. The turbo principles are the same. Many will condemn their expensive turbo for suspected oil leaks past seals. This isn't always the case although high mileage makes it more likely. The turbo oil return to the crank case could be blocked, or there's excessive crank case back pressure due to a failed PCV or blown engine. Lift the oil cap on idle, if there's lots of positive pressure blow back on idle, that's the first issue to look at. If somebody has overtuned your engine it might have suffered?
It’s stock as far as I can tell. It’s got 195k miles on it. We replaced the turbo sensor a few times because it was ruined by oil. The mechanic said it was the turbo failing causing the oil issues. He said he flushed 3 quarts of oil out of the tubes when he replaced the turbo. He said our waste gate wasn’t adjustable and that we could get more performance out of it it we switched to an adjustable one. I’m going to take it somewhere else that specializes in VW’s and see if they can figure it out. Thank you.
 

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OK, 195k is well past the use by date for these turbos so you probably made the right decision. Some turbos are gone at 125k. What your mechanic said is kinda true, but he's ignoring the fact these modern engines are a system with many parts working together in harmony. Car tuners know you can't just change a waste gate valve without considering other parts and system software. Even a Stage 1 ECU tune for +30% more power and efficiency improvement doesn't change any original parts.

You need to go to somebody with V.W diagnostics or a car tuner who can tell you if the engine is running as stock setup without faults and normally measured values within range. In fact the ECU may have already logged out of range boost values as faults which a scan will read out. Once you establish the car is running as stock, you then decide what if any tuning you might want. You don't go to a tune when there could still be a problem to find. I haven't looked in the shop manual but sometimes these cars have to be told to learn and adapt when parts are changed. I know there are shop calibration procedures for their pressure sensors.

Your present gas consumption might give a clue. If the previous turbo was overboosting you would now expect your gas consumption to be lower? I read on some aftermarket sites selling V.W turbos that some were sold as 'performance grade'. Not sure what that means, but if your old and new parts carried the same V.W part numbers they should be the same. I can't see how your old turbo dumping that much oil gave more power output, unless the excess oil was running the engine as a diesel!

Assuming 3 quarts was in the inlet side and intercooler and depending on how long you were running the car like that, you might have to remove the inlet manifold and other parts which could now be clogged up with oil sludge? I think I would be inspecting all those parts first before using diagnostics. If there's oil sludge clogging it won't go away. If your mechanic can replace a turbo, he should know how to deal with the inlet side, PCV, hoses and valve inlets? I bet the air filter has some back clogging too? If you haven't got a clear airway free of oil from the front snorkel all the way to the new turbo and valves, your engine won't breath very well, like it's running on choke!
 

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Recently put an OEM turbo on our 2007 VW EOS. It’s not got as much power now. Is there an adjustment or anything we can do? It’s half the car it was before.
First question I would ask is if the turbo is the same part number as the turbo that was removed and/or confirmed as the correct item? If the turbo and tune had been changed in the past, an OE turbo may not be compatible.
Second question would be was any data logging done to measure the turbo boost of the original turbo and/or the new turbo? This would help correctly diagnose the problem.

Perhaps this repair would have been better entrusted to a VW specialist, you need a specialist to identify the root cause of the loss of performance rather than seeking modifications to improve it.
 

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All true but 3 quarts of engine oil in the inlet and inter cooler core isn't going to help. If the mechanic who replaced the expensive new turbo was competent, he should have checked part numbers and know what that amount of engine oil on the induction side could do? Many make the mistake of sourcing a part themselves which then leaves the mechanic charging up labor without any responsibility for everything working, or a warranty afterwards. If you know what you are doing with a used part it can work. But on an expensive dealer price part I would have left all the decisions and risk to the mechanic?

He may have spent a lot of labor time fitting the new turbo and just left alone the work to thoroughly clean out the induction side as soon as he tried the engine and it ran?
 

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All true but 3 quarts of engine oil in the inlet and inter cooler core isn't going to help. If the mechanic who replaced the expensive new turbo was competent, he should have checked part numbers and know what that amount of engine oil on the induction side could do? Many make the mistake of sourcing a part themselves which then leaves the mechanic charging up labor without any responsibility for everything working, or a warranty afterwards. If you know what you are doing with a used part it can work. But on an expensive dealer price part I would have left all the decisions and risk to the mechanic?

He may have spent a lot of labor time fitting the new turbo and just left alone the work to thoroughly clean out the induction side as soon as he tried the engine and it ran?
Certainly that much oil is a significant concern and knowing for certain its origin (and on the surface it seems logical the turbo was the cause) is key in this situation. On the surface though, one would think that with a new turbo and all that oil flushed out of the intercooler that performance would be improved. Thus my reasoning in saying a VW specialist is needed to run diagnostics and determine what issues exist in this engine.
 

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Thanks for this great thread. I too have a 2007 EOS 2.0 with about 70K miles. The engine leaks a little bit (but noticeable) on garage floor. I took it to a "foreign car mechanic" and they quoted USD $3,800 to replace the turbo. There was no indication about settings, etc.

I then found another garage that only services VW cars. They quoted $2,400 for a Borg-Warner after-market turbo, but also said it was fine to keep running the car even if the turb was leaking (i.e. put cardboard on the garage floor).

So, it's good to know now to ask questions about sensors, settings, etc if I ever do get the turbo replaced...
 

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IMHO 70K is low mileage for a turbo? Do the basic check first: The turbo bearings and seals are fed from high pressure oil but it's drained away under gravity back into the sump. With positive crank case closed loop engine breathing systems on these cars, pressure in the sump with engine running should always be negative, zero and never positive. If crank case/sump pressure is positive, pressurised oil fed to the turbo cannot drain back and gets pushed out of the seals into inlet hoses and/or out to the exhaust (burning as blue smoke).

You can't use the dipstick, but if you get hold of a V.W oil filler cap (many are the same), drill a hole through it and fit a long pvc tube formed into a 'U' with some colored water in it. You should be seeing a partial vacuum of about 4 inches water gauge on idle. I used a gas engineers water manometer - same thing but fancier. Positive pressure indicates a problem with the PCV system or engine wear.

Diagnostics doesn't measure crank case back pressure!
 
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