Blue smoke started coming from the exhaust today, out of no where - Diesel Forum

BVA · 01-14-2007, 02:43 AM

Truck is a 94 Turbo IDI with 110K miles on it, runs perfect, tons of power, and out of no where it started smoking blue today. Initially when sitting at idle fully warmed up, I could see it smoking a nice cloud in the parking lot. I shut the truck down for a few minutes, then took off and everything seemed fine. After another 10 minutes of driving, I'm coasting/decelerating down a long hill... I look back and see blue smoke coming out of my exhaust pretty heavily. I give it a small stab of pedal, and a puff or so, then it clears up.

Under heavy throttle, nothing, boost looks fine, totally normal, exhaust temps are fine as well.

It has been about 20 degrees out lately, and the high temps are only a few degrees more, but this just started today.

I wondered if it wasn't a turbo seal going south, so that on decel it sucks oil past the seal. How many miles are you guys getting out of these stock ATS turbochargers?

Truck is meticulously maintained, fuel filter, oil, just had the fuel line seals replaced 3 months ago, etc. Truck has been running perfectly for the last 6 months, no issues at all.

Thanks for any help you can offer.

cdnsarguy · 01-14-2007, 03:58 AM

I also would think Turbo seals, but how old is the CDR valve and when was maintenance last done..

BVA · 01-14-2007, 01:06 PM

Sorry for my ignorance, but what is the CDR valve? What usually needs to be done to do maintenance to it?

Also, I know on some diesels they can actually run away if enough oil gets by the turbo, does anyone know if this is even possible with the IDI?

Mr_Roboto · 01-14-2007, 04:04 PM

[ QUOTE ]
Sorry for my ignorance, but what is the CDR valve? What usually needs to be done to do maintenance to it?

Also, I know on some diesels they can actually run away if enough oil gets by the turbo, does anyone know if this is even possible with the IDI?

[/ QUOTE ]

Crankcase Depression Regulator valve, a diesel's equivelent to the PCV valve. On the turbo engines there are moved, maybe in the valve cover? Kinda looks like a tuna can.

It would take a major failure for the engine to pump enough oil in for it to runaway. Runaway is more common in coal mines, natural gas fields etc where there is a fuel source in the air.

BVA · 01-15-2007, 06:46 PM

What is the maint procedure for that CDR... replacement, clean it out, etc.

Funny thing is, the next day it totally stopped, and hasn't happened again since.

Wierd, not sure why it did that. I guess its possible that the turbo seal is seaping, and just not enough for oil in the exhaust right now.

Mr_Roboto · 01-15-2007, 07:58 PM

Replace the CDR then clean it out regularly. That way you are starting with a known good unit. You can get the CDR at the dealer or order at a parts store. E3TZ-6A665-A "Adapter assembly for Crankcase Ventilation" Also known as the CDR (Crankcase Depression Regulator) Valve ALL YEARS

There is a rubber seal inside that can deteriorate and allow excessive flow.

BVA · 01-15-2007, 08:50 PM

Well, if early detection of the CDR beginning to fail shows itself with sporadit blue smoke, would it typically show itself at idle, and under slight decel conditions?

I found the part you mentioned, its like $60 at the dealer which isn't too bad, but I don't want to end up getting that if that isn't the issue.

Is there anything I can do to more clearly determine if that is the source of the problem, or to rule out the possibility of a turbo seal? I know that it depends on a lot of variables, but I thougth the turbos lasted quite a bit longer than 110K miles, especially as religiously as the oil has been changed on this truck.

Thanks for your help....

Thudpucker · 01-15-2007, 09:39 PM

If it was smoking at an Idle while warming up, you may have a bad Glow Plug. One or two cold cylinders, with excess fuel, only at the cold engine warming up.

Also, I dont know what I'm talking about on this one, the little Valve stem seals (little rubber top hats on the valves themselves) if the 7.3's have them, might have failed.
When the engine is still cold, at an idle, the amount of oil in the valve covers sometimes doesn't drain out quickly enough and you get some oil up above the Valve stems.

Blue smoke when backing off, as in going down a hill, used to (0n older gassers) means valve guides were loose.

I dont know of any reliable way to trouble shoot that problem, aside from taking it apart and looking.

Mr_Roboto · 01-15-2007, 10:33 PM

[ QUOTE ]

Blue smoke when backing off, as in going down a hill, used to (0n older gassers) means valve guides were loose.

[/ QUOTE ]

Gassers pull oil through the guides under de-celeration because engine RPM is high and the throttle plates are closed, causing very high vacuum.

It doesn't transfer to our diesels, since they don't have throttle plates. Our diesels actually work opposite, they have the highest vacuum at high RPM since the restriction is the air filter, rather than throttle plates.

BVA - you should change out the CDR as basic maintenance. A clogged CDR will flow too much, which puts oil into the manifold, which causes increased EGT's in the 2 rear cylinders.

graytrain · 01-17-2007, 11:48 AM

BVA~
I had the same problem with mine(exact same). about the same mileage on the odometer. I was coming out of wyoming though when it happened to me. it WASNT the turbo. NOT the CDR. Problem was located to the low lift fuel pump not pushing enough volume. (now would be a good time to put a holley red in if you have the time and budget) Second and the main part of the problem was the IP was worn out. The guy at the local pump shop said my advance was severely worn out.
My .02 is to change the Injection Pump, repair for the low lift pump and use a fuel treatment from now on. I got another 20K miles before I changed the pump but it smoked BAD until then.

Mike
Smoked like a train off a 15 mile grade like I was spraying for mosquitos.

BVA · 01-17-2007, 08:21 PM

Hmm... its strange, as the problem hasn't happened to me since it first did it on the weekend.

Did yours come and go? I have been told you can get decent deals on Injection Pumps these days, and go ahead and get the one that is pumped up a bit (I can't remember the diesel pump guy on here, plus he does the high flow injectors).

Any recommendations on where to get one? Also, what is the best way to tell if it is my pump, any tests I can run?

One last thing, why would a transfer or injection pump blow blue, is it allowing oil to get past something?

Thanks for all of the help....

graytrain · 01-18-2007, 11:57 AM

Yes, mine did in and out for about 3 months, then constantly everyday!
IP's are fairly easy to swap if you take your time and be careful (retaining bolt in the front cover) The low lift pump test is easy. takes 2 people and you time/measure the VOLUME of fuel coming out as well as testing the PRESSURE.
As for the color. Funny thing about diesels is that fuel related problems will blow black when over fueled, white when underfueled and everything in between. The main thing that I believe is that the oil in the cylinder that is burned during normal, hot combustion is not being burned so it transfers out the exhuast only 1/2 cooked. (thus the BOOB type engine)
hope your questions have gotten answered.

Mike