Blue smoke and diagnosis

[CFoye]

Long story.



I had a Smarty Jr. on 05' Dodge for about 25,000, Performance setting, truck now has about 105,500 miles. It always exhibited black smoke on hard acceleration and had no other problems. Here comes the hard part. Last weekend I was on a 160 mile trip, whereby I was on cruise control for about 3 hours, pulled into a fuel station and the thing just started spewing blue smoke at idle. I fueled up and started her back up and no smoke. Next day, no blue smoke at startup but, blue smoke after I start driving around and when stopped. The blue smoke will eventually go away with lots of driving and warming up. If I get on it, I'll get blue smoke that goes to black smoke (black I would consider normal) The engine idles just fine, haven't noticed any loss of power, no knocking etc. I pulled the Smarty off and I'm now at stock to see if the smoke would go away. Same symptoms. Noticed that the valve cover seems to be leaking oil out. So, after shut down today, I pulled the oil filler cap and it just about blew out of my hands.

I'm wondering if I scorned a piston, or have bad rings or have some other sort of issue, injectors, whereby I'm getting excessive blow by and blue smoke and yet power and idle seem fine.

 

[FourBarR]

Is it using any oil,more that normal? Should not be any pressure in valve cover with engine stopped. Check your crankcase breather ,do you have the bottle at the front of the front gear cover ? If not is there a hose from the breather that may be kinked blocking the vent and allowing pressure to build up in the engine. The leak at the valve cover could be a sign of this. Hope this helps.

 

[rscurtis]

Smell the exhaust. If it burns you eyes, it's fuel. If not, it could be oil burning. In any case, it would seem you have an excessive blowby problem, which is not a good situation. What air filter are you using?

 

[CFoye]

FourBar - I haven't checked oil level. What bottle are you referring to?

rscurtis - I'm running a Fram drop in air filter. I'm guessing excessive blowby is caused by bad rings.

 

[Prairie Dog]

I would check for a leaking seal in the turbo.

 

[CFoye]

PD - how do you check for a leaking seal in the turbo?

 

[Wingate]

Check the blowby tube to make sure its clear, check the turbo outlet pipe for oil residue... but excessive blowby is bad. . When you pull the oil fill cap with it idling, do you see a steady puff puff puff??

 

[JJPage]

I would check for a leaking seal in the turbo.

DITTO! Agree with PD.



Pull your intake tube off so you can see the turbo compressor vanes (engine shut down of course), look for any oil residue, grab the turbo shaft and check for play. You will have radial play, but not so it touches the housing, you should not have any axial play, the shaft should not move front to back, if it does you can pass oil into the intake and exhaust causing blue smoke.



Let us know what you find.

 

[CFoye]

thanks for the tips. I pulled the intake tube off and sure enough there is oil residue around the turbine venturi. There is some up and down play but, no back and forth play.
So, if this is the problem, how do I go about fixing it? Does it require a new turbo or is there a turbo bearing and seal kit?

 

[B.G. Smith]

Long story.



. So, after shut down today, I pulled the oil filler cap and it just about blew out of my hands.

If you still had pressure after shutdowwn your cc vent is plugged. bg

 

[Hawk]

B. G. Smith is right. The turbo will have some residue on it and from the way you explained it, its still in good shape. Another thing to consider, If the turbo was failing how would that cause excess pressure under the valve cover? It wouldn't. The vent would be my first stop as others have stated and then go deeper into the engine. After the vent your next stop would most likely be a leak down test. JMHO on this and keep us posted on what you find.

 

[rscurtis]

After re-reading the original post, you and BG are correct. Is it also possible that the elevated CC pressure could restrict oil draining from the turbo and force it into the exhaust?

 

[B.G. Smith]

If the vent is plugged it would be interesting to know the oil being used and the change interval? bg

 

[JJPage]

Yes, any restriction in the turbo drain tube will cause oil to back up, whether from a kink in the tube, not having a continuous downward flow, or I would guess, excessive cc pressure. Clean out your cc vent or replace, see what happens.



I also agree with hawk, by your description, the turbo journal bearings are good.



Jess

 

[CFoye]

I did have an extension tube and rag tie wrapped to the CC vent. I pulled it off and then pulled the CC breather to make sure there were no other obstructions. Once I did that, I haven't had any blue smoke. So, I'm guessing the rag caused enough restriction on the CC venting to cause oil to be pushed into the cylinder.
Question now becomes, where was the oil being pushed into, cylinder via valve stems or through turbo seals?
I don't think I've done any damage to the motor, been more than a day now and everything is running great, smooth idle, plenty of power, no blue smoke at idle or acceleration and just a bit of black smoke on acceleration.
Thanks for all your help, this is a great resource.

 

[Wingate]

may have been pushing it by the mechanical seal into the turbine side of the turbo. Typically, this is just a piston ring type seal...

 

[B.G. Smith]

Could have been being forced down the valve stems. I wouldn't sweat the turbo seal, the pressure in the engine would be at equal pressure on the oil and drainback side of the turbo so it really shouldn't be a problem. bg