alright, whats it called?

[moneypit_K5]

on my 6.5 diesel engine, theres a vent hose between the air box and the oil fill tube.

And inline, theres a big metal PCV valve looking thing with a 3rd hose outlet.

I believe it is meant to redirect any oil back into the engine.

what the F is that valve called??

 

[6.2Blazer]

CDR = crankcrase depression regulator

 

[moneypit_K5]

beautiful.

now does it need to be there? or can i re out the hose so it just bypasses the oil without the line going into the airbox?

 

[moneypit_K5]

So is it prudent to eliminate this regulator rather than spend the $60+ to replace it?

It seems to have failed me, im getting major oil leakage from my airbox. My theory is that the valve has failed and now the turbo is sucking oil from the fill tube. very frustrating.

 

[sloth]

It has always been my understanding that eliminating the CDR will result in excessive crankcase pressure and you will start to blow oil out of the crank seals.

 

[moneypit_K5]

Im not planning to eliminate the venting aspect of it, I thought I would just put a breather on it instead of running the line to the airbox. that way the turbo wont pull oil.

 

[K5dreamer]

maybe vent it into the airbox ahead of the air filter?

the breather idea wouldnt pass visual emissions inspection.

other than that, i cant think of anything bad about doing that.

 

[moneypit_K5]

maybe vent it into the airbox ahead of the air filter?

the breather idea wouldnt pass visual emissions inspection.

other than that, i cant think of anything bad about doing that.

it runs into the banks airbox now. thats the problem. somehow there is a major amount of oil gettin in there from the crank case. Im talkin MAJOR oil. Like, the side of my truck is slicked down, undercarriage, fenderwell has standing oil etc. Its irritating because the engine itself only has 35k on it and doesnt leak a drop. its all coming from that hose.

as far as emissions, not too much of an issue here being a diesel. one of the many perks of owning one, i guess. i take it you gotta put your 6.2 through in commiefornia?

 

[K5dreamer]

naw, im here in VA, no emissions on the truck, just a tree hugger

but it seems with the ammount of oil youre loosing, it would be greener to just use the breather

although its been my experience that the CDR always has oil in it. Id actually get new hoses and new hose clamps. sounds more like you have a leaky hose than a CDR problem.

 

[Russell]

The CDR is actually a pretty important piece of equipment. As mentioned above, without one installed on your truck, you will wind up with blowby and leaky seals all over the place due to some strong crankcase pressures. All CDR canisters have oil in them, but they wouldn't be able to collect enough oil to puke it into your air box in the volume you've described... I might suggest you have a leaky turbo bearing seal, return or pressure line.

 

[moneypit_K5]

the turbo bearing seal was the first thing i thought too.

after tearing into it twice, i finally discovered that the outlet of the CDR hose had a pretty good seep even on hte outside of the air box.

All I want to do is change the location of the hose that vents into the airbox. I dont want it to vent there, I would rather it vent somwhere else.

couldn't i install a breather there? or even run it back into the crank case? Or does it actually need the vacuum from the intake in order to function?


My theory is that the CDR actually went bad. thus, allowing the oil it would normally redirect- dump right into the airbox via the intake suction.

Unless Im mistaken about what the CDR actually does.

but either way, I know beyond a shadow of a doubt that the oil is coming solely from that line that connects to the CDR.

 

[Russell]

It is pretty unusual for your engine to produce that much oil mist, but I suppose anything is possible!

Here is a cheap way to test your valve before you go and purchase a new one:

http://flashoffroad.com/Diesel/CDR/cdrvalve.htm

You can vent the CDR to atmosphere like old tractors etc used to, but I would personally consider that a bit irresponsible. You have a perfectly good way of dealing with the crankcase vapours by re-burning them in the engine, no need to vent them to atmosphere, esspecially if you are pouring oil all over the place.

And no, you do not need the vaccum from the turbocharger for the CDR to operate. The old 6.2L diesels have a CDR on them naturally aspirated, and becuase a diesel creates no vaccum NA, it is clear they function without it. That said, I believe there is a difference between an NA and turbocharged CDR valve (different spring rate internally). If you are running a 6.2L valve on your engine, that may explain why it is consuming so much oil.

A new CDR valve is about 80 bucks from Napa, they call it a PCV there

 

[moneypit_K5]

thanks for the link Russ. I wouldnt vent it into the atmosphere, but I could easily vent it back into the crank case.

I beleive my whole issue is that the turbo is creating enough vacuum to force oil into the airbox. II think Im going to just buy the CDR. Im positive its bad, and that link just confirmed it.

If the CDR is stuck open oil mist from the crankcase will be sucked into the engine and burned as fuel

the way my system is plumbed, the airbox is lower then the CDR, and the intake is higher than both. so the oil never really makes it up to the intake, just collects at the airbox.

 

[Russell]

Ah, I can see that being a problem! On my turbocharged 6.2L, the CDR is vented directly infront of the turbocharger vanes from the top of my intake tube. The turbo sucks any vapours up pretty much immediately and fires them back into the engine to be burnt. However, my engine is very fresh, and has little to no noticeable vapour coming off it, so everything stays pretty clean.

I'd be a bit concerned about dumping it back into the crankcase, as it'd build pressure in there, and potentially keep any moisture that is inside the engine from being removed. Lots of the vapour you see will be water vapour, which isn't exactly desirable to be inside the engine.