AFAccord

-10.5:1cr F23
-Garrett T3/T4 57 trim
-Motor and turbo have around 8,000 miles on them

I've noticed that my car has begun to give a puff of blue smoke when I take off from idling at a light. Doesn't do it every time, just occasionally. It's most apparent when I leave work in the afternoons; I start up the car (no smoke), drive 2 miles to the post office to check my mail at no more than 30mph and shut her off. When I come out and restart her, I get a nice big puff of smoke for 2-3 seconds.

I was fiddling around with the charge piping one weekend and noticed the turbo has some caked on oil around the compressor where the housings meet. Pulled off the coupler and find semi-wet oil in the coupler, and more oil heading down the charge pipe.

I'm suspecting my smoke issues may be related to the oil that's slowly coming from the compressor. The car hardly smokes at all on full boost pulls. What could be causing this, and what's the best course of action to fix it?

TheShodan

iTrader: (14)

Usually outside influences would create this condition:

-Pressurized crankcase pressure

-Oil drain line. Either not properly routed, or kinked somewhere. (For example, return line may be pointing up by the oil pan instead of a steady slope, or the line is kinked or damaged in some way.

pictures of the ENTIRE turbocharger and its routing from oil inlet and oil return will be helpful.

AFAccord

Full setup.





Here's my oil feed. Comes off a T-fitting bolted to the firewall, which is fed from a line directly from the stock oil pressure sensor port.







Here's my oil drain. Looking at it head on, it's perfectly vertical.

wantboost

iTrader: (2)

compressor seal is on its way out

TheShodan

iTrader: (14)

That may be do, but it doesn't "just happen" all of a sudden..there is a cause, if that indeed is the case.

How long ago did this start?

AFAccord

I can't recall a specific time. I'd have to say it's been gradually getting more noticeable over the last 1,000 miles or so. The turbo was brand new, so I just wasn't expecting to have an issue with it so soon.

The valve seals were replaced with the motor build. I'm just curious why it's worst at the second startup when the motor is still cold. Would it have anything to do with the higher oil pressure while the engine is warming up?

TheShodan

iTrader: (14)

Only if you don't have the proper sized restrictor into the turbocharger, but you would have noticed that immediately, not over time.

What's your oil pressure at start up?

AFAccord

I can't remember what my numbers are on a cold start, I'll have to see if I have any videos to reference since the car is still down for the winter. Once warmed up, I'm at a solid 62psi 90% of the time, peaking at 70psi at WOT. Not running an oil restrictor to the turbo because I was told it was not needed.

TheShodan

iTrader: (14)

Yeah. the need of an oil restrictor is based upon oil pressure at the line, not for the type of cartridge it is. (i.e. journal bearing vs. Ball-bearing). For Garretts.. anything over 50psi of oil pressure on a journal bearing turbocharger needs a type of restrictor, the question is really more of what size. Here, I see two potential problems. 1) crankcase issues, 2) lack of proper oil restriction..

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Well, let's first break the symptoms down a little just from what we can all see from the photos you provided and the questions you've answered so far, and rule a few things out.

What we can Rule Out

1. We can rule out over-restriction, (which could cause over-pressurization of the compressor seal causing leakage), because you don't have any restrictor on the turbo at all.. That's not a great thing, but for the sake of singling out the compressor side oil leakage, let's assume that the oil feed line is fine, even though it really isn't. Its better to have a little too much oil, than not enough anyway.

Now, having said that, for the purpose of understanding overall turbo "health", at over 62psi of oil pressure, anyway, you need a proper 1/4NPT .060" Restrictor. This is what I think is causing the "puffs of smoke" during your idle starts and stops.

2. None of the clamps, flanges or brackets in the compressor area are loose, so that rules that out. The intake manifold isn't cracked or damaged, or you'd see a boost leak that would contribute to compressor oil leakage, so let's rule that out.


3. Excessive dirt build up on the compressor housing. - Yeah, I know, it doesn't seem like a big deal, but that tears down the seal between the backplate and cover. It usually doesn't mean much, but again, nothing to worry about here. -Ruled out..

4. Plugged oil filter - I doubt that here, you'd have to not change it for YEARS before that could be a factor.. Ruled out.

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So, that leaves few things left.... But I think I see two culprits.

4 main possibilities -Culprits are in Red

A. Collapsing or restrictive air inlet pipe to the turbo. Some of the less expensive air filters or even the AEM "Dry filters" tend to collapse when going into higher boost pressures. I know many don't find this a big deal, but actually having a small section of intake pipe between the turbocharger and the filter has massive effects on the turbo's ability to ingest air. No matter what the configuration, its always best to have some sort of pipe going in between the two; even if it means it has to face downward towards the body of the car. When you have the filter too close to the turbo inlet, it causes a large pressurization against the thrust bearing and front seal. Over time, that can wear these items out.

I don't think this is the case as much here as the culprit (at least from what I can see), because that kind of damage would be in addition to another factor below, but not having some sort of intake isn't helping you.

B. Worn front compressor side journal bearing - If you have a lot of hot shut downs, didn't change the oil much (or use the correct type) that could cause some oil "coking" on the turbine side, the compressor side journal bearing could be wearing out causing some blowby through to the front sealing ring. But this would be due to the hot shut downs and possible carbon within the oil..


C.Turbocharger Compressor Seal Leakage due to lack of crankcase relief. - This seems to be the case from excessive crankcase pressure from either the clogged PCV, or you're not getting enough crankcase pressure relief. Being that you're at over 417whp, 398lb/ft on a 57 trim T3/T04E with a maximum effective range of only about 430whp, I'm thinking you're over 20-24psi of boost pressure. That's a lot for that turbocharger and engine to experience. The compressor seal and thrust bearing are being overpressurized so that the compressor seal is leaking.

But the real issue is the last one. The compressor side leaking is just from going into higher boost points on a regular basis, which, with no crankcase relief, causes the leak that you obviously see. Here's what you don't see.

D. Lack of proper oil restriction The front compressor side may be experiencing over-pressurization from the crankcase to cause it to leak slightly, but I think that its the lack of proper inlet oil restriction that's the main cause. The over pressurization is on both the compressor and turbine side of the turbocharger. That is why you're seeing leakage on the compressor side, and why you're seeing puffs of oil smoke after idle and acceleration. There's simply too much oil pressurization in the gallies and it needs proper restriction.

Getting the proper restrictor will aid in making sure that this issue is eliminated


Remember: turbo sealing rings (aka "seals") are more like piston rings; they were designed to seal the cartridge system of the oil splay that occurs inside, but it is not like a rubber grommet or anything like that. If the sealing ring is over-pressurized, it will leak out, just like an unrestricted turbine sealing ring on the turbine side.

From what I see in the photos you've provided, I don't see any type of crankcase pressure relief by way of an oil/water separator system or "catch can" system,

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Solutions - Areas that need immediate attention are in blue

What this means is that assuming that all your hoses and connections aren't collapsing, and boost control is working properly, that you need to do four things:

1) Get an oil catch can kit to relieve crankcase pressure - This helps eliminate the compressor cover leak. It doesn't have to be two -10AN fittings from the valve cover to a battery sized 2-litre catch can like a drag racer. It can be a simple system that uses a smaller can, a one way check valve on the valve cover breather nipple (that would run to the intake manifold), and either drainback or not..

2) Make an intake pointing downward from the filter to the turbocharger. Again, this is the best way to relieve pressure against the thrust bearing of the turbo, and give it long life.

3)Avoid hot shut downs- I don't know if this is something you deal with or not, but after driving, give it 30 seconds or so for the oil to cool down inside the gallies to avoid oil "coking".

4) Get the proper oil restrictor. 1/4NPT for Garrett turbos like yourself that are oil cooled only. This eliminates the blue smoke at idle and starts. DO NOT USE OIL RESTRICTOR PLATES, that have a male fitting on top, and a tiny .065" hole on the bottom. The turbo needs pressurized oil, not from a hole "dripping" into the oil inlet.
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So, here's another question...

Question
What happens if I do all that, and its still leaking?


Answer:
Well, then the turbo needs to have the thrust bearing, compressor sealing ring and journal bearing replaced...Basically a rebuild.

You don't have a lot of time on this before permanent damage could occur.

Sorry for the book, just going through a step-by-step diagnosis..

Hope this helps.

AFAccord

Thanks, that's a ton of good info. You're right, I typically see 20-21psi at high boost on the autobahn, and I know I'm approaching the limits of this turbo but I'm quite content where it's at and not seeking any more power from it.

Let me start by addressing your last concern about crankcase ventilation. It's pretty well hidden by the intake pipe, but the valve cover is in fact vented by two -10AN fittings leading to a small-ish baffled catch can on the firewall. It's a setup I intend on re-working anyway, but I've never had any real surprises by the contents or amount that it collects; it seems to do the job well from what I can tell.




I'll definitely look into making an intake pipe. I might even have a way to route it a short distance to a location where it can collect some cool air from the grill.

I have a smart alarm on the car that also doubles as my turbo timer, so I'm generally quite conscious about letting her idle for a few minutes whenever I've driven the slightest bit rowdy.

How would I go about choosing the most appropriate size if I wanted to add a restrictor? I'll definitely take a good look at my cold start oil pressures and get an idea where I'm at now before I actually install anything.

TheShodan

iTrader: (14)

That's fine, and the compressor cover is not seeing much leakage, but it's definitely coming from over pressurization. It may not be at WOT, but it's definitely happening, even with your current crankcase setup. It may be more from the lack of restrictor than crankcase relief, but it's definitely there.

As for what size restrictor, it's pretty easy in this case with the kind of oil pressures you're seeing, a 1/4NPT .060"-.065" will do the trick. You'll need to know what size line you're using, but it will change your 90 degree fitting to your turbo.

This is a perfect example of both the type and where to get it from by clicking the underlined link below.

B&R Fittings Oil Restrictor for Journal Bearing Turbochargers