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Carbon build up Question

R

Rodd

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Antelope, CA
While I was replacing my ops the other day I looked down the intake holes in the block and go a glimps of something in there. I couldn't tell what it was but it did have what looked like a little carbon build up on it. I am assuming it is in all the holes but the one I saw is on the pass side the 2nd hole I think. Anyone know what it is?
 
Crud build up from the CDR, All 6.5 engines get that unless you do away with the CDR into the intake.
 
I am assuming you had the intake off.

Yes these engines will build up a lot of crap in the valve pockets if they have an EGR
(1500 trucks)

A 6.2/6.5 that has been let sit for a long time can see this crap fall off the valves and into the cylinders. It can then cause issues as the clearance between the head and the piston is very small.

The 6.5 TD does suck a fair amount of oil vapor from tjhe CDR through the turbo and into the engine. This also contributes to the mess but the EGR is the real mess maker


Missy
 
I don't have an egr. It isn't oily. Just carbon on what ever the things are in there. With the intake off the holes are clean inside but for the carbon on whatever the things are in there. They look almost like glow plugs but they are in the intake.
 
Post a pic so we know what you are talking about.

Come to think about it. A round rodlike object going through the intake port. Are you sure you aren't looking at the valve stem for an intake valve?
 
you happen to look at the intake valves. As Missy said, they can have a fair amount of build up that'll break lose someday and is gonna make for nice pitted pistons if not worse.
 
I will venture out and say that I have vented my CDR tube down the back of the engine and into the frame rail where it does drip oil onto the frame. I know this is not environmentally sound but my intake valves and turbo inside look like the day they were assembled.

:thumbsup:Should not be anything the DTR family can't talk about ):h. We can disagree that is normal.
 
If the engine is in good order there should be little oil over the top.

My 94 Burb (after the rebuild 3 years ago) has almost zero oil going into the turbo inlet.

The way the CDR works is to keep a very low level vacuum on the crankcase when the engine is at speed.

This takes all the pressure off the seals and gaskets due to blowby from combustion.

Removing the CDR is not the best program. If your air intake side of the turbo is sloppy with oil it means that you have other issues.

Too much blowby (High miler) and or possibly the CDR Valve is not working properly.

These engines are going to have some carbon build up on the intake valves no matter what as they all do slop some oil over the top and into the air stream.

Now there is a way to clean that stuff out but its time consuming and does carry some risk if you are not careful.

I will describe the procedure.

Rotate the engine (By Hand) and do so until a particular intake is shut tight.
Cap all intakes with something to prevent stuff from falling in. (small parts dirt etc)

Now with a small high intensity light you can look into the hole and with a suitable length narrow long screwdriver, reach in and
break up the carbon heap on the back of the valve.

Now suck the mess out with a shop vac and then be sure there are no remaining chunks that will fall into the hole.

Tiny pieces will do no harm but the large chunks that can fall in can and will cause issue. (Tiny means not much larger than sand)

Once you have a hole clean, move on and rotate the engine and do the next intake valve.

Once you have done all 8 your set.

This is a tedious and time consuming task. I have done it on a couple engines that had a large amount of crap in the valve pockets.

If you dont feel comfortable with taking the time to do this by the numbers, DONT DO IT.

Here are some pix of lots of carbon on the intake valves

Missy
 

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Thanks for all the info guy's and gal. I would take a picture and post it but my intake is all back together for now. I don't want to take the time to pull it off again so soon. What I saw probably was one of the intake valves. The only thing is the whole rod had carbon on it. That is what concerns me.
 
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