Rebuilt turbo, Burning lots of oil constantly, but no shaft play

[dacowgod]

Hey guys,

I have been working on my brothers 1g project for the past 8 monthes. We have torn the engine down to nothing, put new bearings along with new piston rings. We got it back together and put at t25 on it to break it in while we were waiting on parts to rebuild his evo III 16g. .

Anyways..We probably put about 40 miles on the engine . It smoked a good bit when we first started driving it after about 5 miles we didnt see any more smoke (we gave it a hard break in) . .. anyways on to my problem..

I had this evo III 16g on my 2g and it would smoke between shifts, and had some side to side play. When i upgraded to the 50 trim the smoking between shifts went away , so I figured the turbo was ready for a rebuild.

So we rebuilt the turbo, with a kit from Forced Performance, and plumbed it on his car.

Well after priming the turbo, I check for shaft play and theres none, the thing feels great. So, we fired up the car and theres blue smoke. I think, well maybe its the valve seals, so i let it run for about 30 mins idling. Anyways the blue smoke is not nearly as bad at idle but its still there.. We rev the car up a bit, and it pours the blue smoke. So i decided i better do a compression test just to make sure its not rings since the smoke is constant.

Well the compression test yields 160-160-162-162 so Im pretty happy with the results, but determined the smoke must not be from the rings.... and i'm pretty sure its not from the valve seals, since valve seals, will usually smoke when lugging the engine, or between shifts, or right when you start the car. Also the last time we drove the car(it has sat for about 4 monthes) was with the T-25 and the smoking wasnt there... So I come to the conclusion that the oil seal is bad in the turbo.

I think that is the obvious answer, but I am looking for some confirmation , I will take it apart and put the T-25 back on when I get some time for a definite answer but somebody chime in here.

Can the Oil Seal in the turbo be bad, and the turbo have no shaft play??? ..(my guess is yes, since the bearings are not bad, but I did a search, and found no posts confirming that) ..

Any suggestions on what I may have done wrong during the rebuild?? I followed the VFAQ to a T... and it was balanced by a diesel mechanic for me...

I only put in 2 seals that I am aware of, both being O rings, one being around the compressor housing, and the other just right near the thrust bearing. Is there any other seal that I'm not thinking of?...

Well thanks for reading my long post!

 

[DoyoFCT]

I have a few questions

1. Where is the turbo being fed oil from?

2. Are the balance shafts eliminated?

3. What type of return line are you using?

 

[black92_tsi_awd]

Yes, the seals can be dry or cracked. Which has nothing to do with the brearings.

 

[DoyoFCT]

since they're new, i doubt thats the problem though. It is possible that during assembly one of the seals was damaged. I've never rebuilt a turbo so i cannot say if your supposed to, but I would imagine you should use some sort of lube on the o-rings during assembly. If that wasn't done its quite possible one of the seals was damaged.

oh and the reason for my questions above is;

1. sometimes feeding oil from the filter housing can create a problem(too much pressure from bs removal or a clogged oil cooler or other things can create an excess of oil in the housing, and it goes out everywhere.

2. mainly to narrow my theory in the first question.

3. I've had experience with those turbo return line kits that use a cheap hose which can kink up when it heats up, resulting in the same result of too much oil in the Cartridge.

 

[dacowgod]

Well... heres an update....Its not the turbo after all... i took the turbo off and to my surprise its ok....pretty clean inside.. and to my Dismay... #3 exhaust port on the head is literally leaking oil out of it.... :S ... #1 and #4 are also wet, but no comparison to # 3.... So the only thing i presume can be the cause of this is bad valve seals hence the block being rebuilt and having good compression.


Any other ideas????... I know I need to do a leakdown test to be certain but I dont have a leakdown tester, or access to one.... Can valve seals be that bad to cause all the smoke I am seeing.
I suppose oil could be making it through the rings still, though wouldnt my compression be suffering something fierce??

 

[dacowgod]

Thanks for the suggestions about the return line and the oil feed location. It is feeding from the oil cooler... .. I know exactly what you're talking about with it building pressure and blowing through the turbo. That wasnt the case at idle though, there is minimal oil pressure ( in comparison to actually driving) .... The return line is a steel return line from slowboy racing, and the balance shafts are still in the car... Thanks again for your suggestion, after doing a search I'm almost certain its the valve seals, I just had no clue that they could be so bad that you would get constant smoke.... Learn something new every day.

 

[dSmgs-T]

sounds like bad seals to me...does it smoke between shifts only under boost?

 

[DoyoFCT]

yea, valve seals can become so bad that it smokes constantly, but im not so sure I would suspect valve seals if it all the sudden started smoking constantly.

usually when the valve seals go, the smoke comes during idle and will burn off if you blip the gas a few times or during driving conditions. then it will gradually get worse an worse until it can become constant.