I've had this truck about 3 months & have done some parts replacing thanks to you guys. (Dealer priced wastegate solenoid @ $385.00!! NO thank you). From what I've read, the smoke puffing is probably a cracked piston or a broken or stuck ring. The truck idles really smoothly @ 900 rpm but uses about a quart of oil every 300 or so miles. I'm using Lubrication Engineers 15-40 Monolec Ultra with Lucas HD oil stabilizer. I don't want to do too much for power until I know what's going on with the engine. The smoking is not a steady stream but seems to be in time with the rpm & the internal pressure will push the filler cap off if not engaged in the slots.
Thanks so much.

Check the CDR FAQ, bad CDR would be 1st place to look for excess vapor/hi oil consumption

New CDR, will add to sig.

Where can I buy a new cdr cheapest??? Mine has some white smoke from the fill port with my rear seal dipping a small amount of oil as well. HELP!

5.13's ain't good for longevity, but pull the CDR hose off when idling hot, see if same as at oil filler cap.

Oil filler on, CDR hose off

Oil filler off, CDR hose on
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Where is your CDR connected to the intake, Garrett?

OK, Oil cap off, cdr hose on - pulsating smoke at about 7-8 puffs/sec. at idle, dipstick tube - steady smoke, Oil cap on, cdr hose off - slight pulsing & builds pressure better than my I-R air compressor!

Seems like the filter screen inside the valve cover is crudded up - should be the same at either opening, but that is a lot of blowby, in any case.

If you can live with it, pull the valve cover off, clean\replace the screen, replace the nylon rocker-keeper buttons while you're at it

To add a little more info., the truck does not smoke blue from the tailpipe. Is it possible to replace a piston with the engine in the truck? It's probably not worth a full OH.

Yes - you've got the dropped straight front axle, nothing in the way of dropping the pan for an in-frame job.

I would suspect #8, maybe #6 , last two on passenger-side rear, being scuffed\scarred - might see that by pulling the pan, but usually needs the heads off.

Compression check would point the way - pull all the glow plugs out to get max crank rpm, all cylinders should be within 25psi of 400psi

Will do that next. Thanks a lot!!

I have got the same thing going on...I replaced my CDR valve and is still smoking from dipstick and oil filler neck quite alot as described in the thread above.........I am doing new injectors next week while i have the turbo and manifold off.....should I take the valve cover off and replace that screen you were talking about and the nyklon buttons??? thanks

The nylon keepers deteriorate due to heat, and will crumble and disintegrate, so those are in order - you can clean or replace the screen while you're in there.

do you know where i could buy that screen or what it is even called?? thanks and are those buttons the Nylon Rocker Arm Guide Buttons..........thanks again....and if you could give me an explanation why changing these would produce smoke to come out of my dipstick.....I am just not getting it sorry I have just started really working on everyday hahaha on my truck.....thanks again I appreciate it

The turbo draws the vapors from the crankcase, if the screen is clear and blowby is normal - excessive wear causes excessive blowby, which exceeds the capabilities of the system.

Cleaning the screen can help, but it's not the solution if the engine is worn out.

Excess blow-by can cause surging and rpm runaway, with no throttle control - the vapors burn just as easily as Diesel fuel, which is a light oil.

'Nuther words - do the test, clean the screen, see if that helps - pretty sure that screen is 3M pot-scrubber stuff

Check in Parts Point, see if there's a part number for those buttons

What torque specs should i use for the rocker arms after i take them off......should i take them off to replace the buttons.........also if i do will i have to do anyting with the pushrods as in keep them in place or what not...thanks

No need to remove the rocker shafts - just pull the old buttons out with pliers, push the new ones in.

gmctd you never said what the buttons really do?...just wondering

Factory GM manual discusses a process for freeing stuck rings & GM has a product to do it. Or so I read in the GM good book . I haven't tried it though as I've not faced the condition. Might be a good complimentary process to the mini ring change job if you do it.

They're inserted in holes in the rocker shaft at each valve rocker-arm position - they center the rocker-arms on the valves, preventing side-to-side movement.

Being of nylon, they will crumble from long-term exposure to heat - you may notice the turbo-side buttons are darker brown than those on the opposite bank.

Result is the rocker-arm moves out of position as pushrod attempts to open the valve, next time push-rod cannot rock the arm to open the valve - you get misfire, bent pushrods, etc

Factory GM manual discusses a process for freeing stuck rings & GM has a product to do it. Or so I read in the GM good book . I haven't tried it though as I've not faced the condition. Might be a good complimentary process to the mini ring change job if you do it.

So what is this "process" and "product"? I have my doubts that it would help my poor ol' 6.5, I'm just very curious!

i have this problem but my truck runs great is it something to be worry about or not?

What motor oil are you guys running?

mine does it at start up and idle for just a few mins... and it is really light... it quits if it has ran for a few minutes... is this a problem? I run Castrol 15w-40 tection diesel oil... it doesnt seem as if it has a lot of pressure coming from the dipstick tube but the oil filler hole has a small amount of pressure comin out of it... someone let me know b4 i freak out

Factory GM manual discusses a process for freeing stuck rings & GM has a product to do it. Or so I read in the GM good book . I haven't tried it though as I've not faced the condition. Might be a good complimentary process to the mini ring change job if you do it.

I would be interested in this proceure myself.

The process is described in the GM factory manuals. The fluid is a GM product available at the dealers parts dept. I have 96 & 2000 manual sets & IIRC I read it in the Blue 1996 book of which there are two of them. Check the index . IIRC it entailed installing thru GP holes & soaking the rings/pistons.

I use Lubrication Engineers Monolec Ultra #8800 15-40.
Exceeds CF,CF-2,CH-4/SM, Mack EO-M+ & they state "No other brand of petroleum lubricating oil whatsoever, regardless of price, will be found superior in condition to MONOLC ENGINE OIL at the end of any given period of use.
Sounded good to me. I use it in my Blazer with 320,000 + miles, change it @ 10,000 miles & it uses 1 - 1-1/2 Qts. & stopped leaking around the seals.

Ok - main thing is that no-one is using amalie\equiv 20W-30 motor oil in a Diesel engine - that stuff is for gassers............gassers - patooie!

You can use the suggested method on Bill's blog, or you can read the CDR thread in FAQ's for an easy to build manometer.

1-2" water is good result - bubbles in the reservoir indicate excessive blow-by in Bill's lazy-man's ometer.

Similar with the manometer - 1-2" toward the engine is good - 1-2" away from the engine is approaching not good - blows all the water out is highly questionable, at best.

Combined with the simple test suggested earlier, you should be able to get a good handle on the condition of your engine - clean air filter mandatory for all tests.

I use the same Mobil Delvac 1300 15W40 I use in my big trucks. I was always pleased with its performance.

I use Castrol 15w-40 diesel oil. I am going to rip the valve cover this week off and clean the screen inside maybe replace the rocker buttons and see if that helps out....I am hoping that is clogged and is causing my blowby out of my dipstick......anyways what is this method of freeing stuck pistons????I would like to check into that...thanks -Tyler