Trying to understand why the turbo failed..

[dean]

Do you get boost with your turbo? If you do than your turbo isn't blown. IMO

[DailyDriven'88]

Yep, still spooled up nicely and held boost just fine. My theory is i must have caught this failure at a super early stage. When the turbo gets inspected, we'll all know for sure.

[x98boardwell]

Daily,

Check out this thread. My turbo went out and I ended up rebuilding my motor because of it. I had some major vacuum leaks. After the rebuild (turbo and motor) I used the 3LDZ for awhile until I broke the motor in and then added the K27s. The turbo blew within 10 minutes of driving and is currently "at the shop" waiting for a response of "what failed". My engine is spot on and running like brand new. Nothing wrong here other than the turbo from my situation.

See the link and provide your perspective. I hope this helps.

While I was driving, everything was fine until.....

Bryan

[DailyDriven'88]

Originally Posted by x98boardwell

Daily,

Check out this thread. My turbo went out and I ended up rebuilding my motor because of it. I had some major vacuum leaks. After the rebuild (turbo and motor) I used the 3LDZ for awhile until I broke the motor in and then added the K27s. The turbo blew within 10 minutes of driving and is currently "at the shop" waiting for a response of "what failed". My engine is spot on and running like brand new. Nothing wrong here other than the turbo from my situation.

See the link and provide your perspective. I hope this helps.

While I was driving, everything was fine until.....

Bryan

I remember reading that thread when you started it. The K27 i have took about 1500-1600 miles before I discovered the oil. The majority of those miles were easy going too...just mostly freeway cruisin.

When I yanked off the intake manifold a couple months back, I discovered a few vac lines in questionable shape as well as a few injector blocks with small cracks. I changed all the vac lines, all the injector blocks, and all 3 injectors on the driver side. Being an ex benz tech I have access to the factory bench tester for the injectors. After testing, 3 looked questionable so i changed them. After all that stuff, suprisingly the car felt like it ran the same!

I even dropped the b&b's last week b/c of one f'd up exhaust stud. It ended up needing a time sert but at that time, the exhaust chambers were all nice and dry, with no excessive build up of any kind. They all matched each other in color as well. This engine seems "tight" and performs wonderfully with less oil consumption than the 88 3.2L ive got sitting beside it.

Im almost convinced its either the faulty timing, something in the oil, or of course a defective turbo somehow.

[Speedy Squirrel]

There is a turbo drain oil pump. It sucks the oil out of the little sump that bolts onto the bottom of the turbo. It is driven off the front (end closest to the front of the car) of the left cam. There are two little pins that drive it. You didn't leave them out by any chance?

If you don't pump the oil out, it could fill up the compressor housing after the engine is shut off. The compressor seal is a dynamic seal. It could probably hold most of it back while you are running, but not after you shut off.

[DailyDriven'88]

Originally Posted by Speedy Squirrel

There is a turbo drain oil pump. It sucks the oil out of the little sump that bolts onto the bottom of the turbo. It is driven off the front (end closest to the front of the car) of the left cam. There are two little pins that drive it. You didn't leave them out by any chance?

If you don't pump the oil out, it could fill up the compressor housing after the engine is shut off. The compressor seal is a dynamic seal. It could probably hold most of it back while you are running, but not after you shut off.

Operation of the scavenge pump has already been verified when I installed the new turbo. Thanks though.

[mb911]

ok I keep seeing this pop up can someone explain to me how timing has anything to do with oil in the turbo with the exception of the engine detonating and breaking the ring lands?

[JFairman]

The way I understand it is if the timing is too late as in not advanced enough at higher revs than the air/fuel may still be burning somewhat during the exhaust stroke.
That would raise exhaust temperatures, raise the turbo temperature, and possibly burn the seals, coke the oil and ruin the 2 bearings on the turbo shaft.
The turbine or hot side uses a piston ring type seal in a groove on the shaft that can take alot of heat and the compressor side uses a silicone o-ring seal on the shaft that can only take so much heat.

I may be wrong about the timing analogy, but my HFS turbo burned up from brand new in 800 miles and I have the old turbine wheel that looks in fine shape attached to the blued shaft with burnt bearings and piston ring seal on it sitting on a shelf in my living room...
The turbo's rebuilt with new parts other than the compressor wheel and back in the car.

[DailyDriven'88]

Well explained J. What was cause for the overheating issue with yours?

Now someone please tell me why ImaginAuto doesnt answer their phones and as well as doesnt return voicemails. Gotta love it...

[RarlyL8]

I am a distributor for the K27 line and will help you with this. E-mail sent.

[JFairman]

[QUOTE=DailyDriven'88;4566810]Well explained J. What was cause for the overheating issue with yours?

Not sure.. it's all speculation and I would rather not make guesses about that public.

[DailyDriven'88]

Originally Posted by JFairman

Not sure.. it's all speculation...

Same here, I understand.

[mb911]

Originally Posted by JFairman

The way I understand it is if the timing is too late as in not advanced enough at higher revs than the air/fuel may still be burning somewhat during the exhaust stroke.
That would raise exhaust temperatures, raise the turbo temperature, and possibly burn the seals, coke the oil and ruin the 2 bearings on the turbo shaft.
The turbine or hot side uses a piston ring type seal in a groove on the shaft that can take alot of heat and the compressor side uses a silicone o-ring seal on the shaft that can only take so much heat.

I may be wrong about the timing analogy, but my HFS turbo burned up from brand new in 800 miles and I have the old turbine wheel that looks in fine shape attached to the blued shaft with burnt bearings and piston ring seal on it sitting on a shelf in my living room...
The turbo's rebuilt with new parts other than the compressor wheel and back in the car.

I understand what your saying just not sure I buy it. maybe if running hi boost levels generating allot of heat =lean.

[A930Rocket]

I think JFairman got it. If the timing is retarded, the exhaust will get red hot. I did this when I was timing my car with an advanced timing light and didn't set it right. It idles fine, runs ok, but the exhaust... OUCH!

[DailyDriven'88]

Originally Posted by A930Rocket

I think JFairman got it. If the timing is retarded, the exhaust will get red hot. I did this when I was timing my car with an advanced timing light and didn't set it right. It idles fine, runs ok, but the exhaust... OUCH!

This may not be accurate enough, but fwiw while it was on the dyno, I could see the exhaust (at the part closest to the turbo) and it never got red hot.

Kevin @ Ultimate feels its most likely due to something in the oil. I cant wait until he inspects it and comes to a conclusion.

[cl8ton]

Daily, can you post/pm what the findings were on your k27, after the autopsy?

Originally Posted by DailyDriven'88

Kevin @ Ultimate feels its most likely due to something in the oil. I cant wait until he inspects it and comes to a conclusion.

[DailyDriven'88]

Originally Posted by cl8ton

Daily, can you post/pm what the findings were on your k27, after the autopsy?

Sure, no problem.

[911st]

Found this:

5. Common Causes of Oil Leakage

A properly installed turbo should NOT leak oil.

There are, however, instances where oil leaks occur. The most common causes,
depending on the location of the leak, are:
Leakage from compressor and turbine seals

Excessively high oil pressure
Inadequate drain drain is too small, does not go continuously downhill,
or the location of the drain inside the oil pan is located in a section that has
oil slung from the crank causing oil to back up in drain tube. Always
place oil drain into oil pan in a location that oil from crank is blocked by windage tray.
Improper venting of crankcase pressure.
Excessive crankcase pressure.
Oil drain rotated past the recommended 35°.
Leakage from compressor seal
Excessive pressure across the compressor housing inlet caused by:
Air filter is too small.
Charge air tubing too small or has too many bends between the air filter
and compressor housing.
Clogged air filter.
Leakage from Turbine seal
Collapsed turbine piston ring from excessive EGT’s.
Turbo tilted back on its axis past recommended 15°.

[JFairman]

Thats a good list.

This is the first time I've heard of this one...
"Excessive pressure across the compressor housing inlet caused by:
Air filter is too small."

Would that mean excessive low pressure or even some vacuum at the compressor inlet if the air filter is too small, or intake pipe is too restrictive, or control pressure is so high the sensor plate is hardly opening? ...just thought of the last one
...meaning another possiblity is if the turbo is having a really hard time sucking in air then it might also suck some oil past the turbo shaft seal?

[DailyDriven'88]

There are probably a lot of special circumstance/extreme situations listed above, but all are good points none the less.