Author Topic: 6.2 diesel cdr valve  (Read 6863 times)

Offline thelincolnguy

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6.2 diesel cdr valve
« on: January 10, 2016, 09:56:12 AM »
Hi. I have a 1985 6.2 diesel. I was wondering if the cdr valve was an emissions control valve and could it be deleted, along with the lines going to the intake manifold and the fill tube
Thelincolnguy

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Re: 6.2 diesel cdr valve
« Reply #1 on: January 10, 2016, 03:13:48 PM »
its there for a reason. i dont think its emissions related since its a diesel and most times they dont get tested for emissions
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Online roundhouse

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Re: 6.2 diesel cdr valve
« Reply #2 on: January 11, 2016, 07:39:50 AM »
I think it's a one way valve usually  to prevent turbo pressure from getting into the crankcase
Not sure of its purpose on a non turbo engine


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Offline K20Detroit

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Re: 6.2 diesel cdr valve
« Reply #3 on: January 11, 2016, 05:26:15 PM »
I was curious about this as well.
On my Impreza, I have a similar valve known as a PCV valve that needs to be cleaned or replaced every few years or else mileage/performance suffors. A light film of oil develops, eventually turning to sludge, clogging the valve.
I can't find much on the CDR, in terms of operation, cleaning, etcetera.

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Re: 6.2 diesel cdr valve
« Reply #4 on: January 12, 2016, 01:44:33 AM »
It's not just for turbo pressure but blow by. Know my cummins doesn't have one but it has a breather tube
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Offline K20Detroit

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Re: 6.2 diesel cdr valve
« Reply #5 on: January 12, 2016, 01:40:25 PM »
Its purpose is the same on a gas job; to prevent excess pressure in the crank case.
Too much causes issues with blowby and seals. Too little isn't good either.

Offline thelincolnguy

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Re: 6.2 diesel cdr valve
« Reply #6 on: January 17, 2016, 08:57:27 PM »
Hey yall im going out on a limb here and trying something. I removed the entire cdr assembly and left only the hose that came off the fill tube. I capped off the intake and rolled over to autozone and picked up an edelbrock valve cover breather. I removed the rubber grommet and pushed the breather right down into the tube coming off the filler. Then i installed a hose clamp. On top of cleaning up the engine bay, this will also keep oil out of the intake and relieve crankcase pressure. I have some driving to do to verify this modification, so let me know your opinions.
Thelincolnguy

Offline TGPJr

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Re: 6.2 diesel cdr valve
« Reply #7 on: January 19, 2016, 04:58:07 AM »
Hey yall im going out on a limb here and trying something. I removed the entire cdr assembly and left only the hose that came off the fill tube. I capped off the intake and rolled over to autozone and picked up an edelbrock valve cover breather. I removed the rubber grommet and pushed the breather right down into the tube coming off the filler. Then i installed a hose clamp. On top of cleaning up the engine bay, this will also keep oil out of the intake and relieve crankcase pressure. I have some driving to do to verify this modification, so let me know your opinions.

Good Luck.
Let us know it works out for you after you replace your engine gaskets and seals.
That valve is part of the crankcase ventilation system and needs to be there.
It has nothing to do with emissions or turbo.

You have to remember that this engine has a 17-1 compression ratio.
Lot of back pressure being made inside.
Tom
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Offline K20Detroit

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Re: 6.2 diesel cdr valve
« Reply #8 on: January 19, 2016, 01:29:12 PM »
Hey yall im going out on a limb here and trying something. I removed the entire cdr assembly and left only the hose that came off the fill tube. I capped off the intake and rolled over to autozone and picked up an edelbrock valve cover breather. I removed the rubber grommet and pushed the breather right down into the tube coming off the filler. Then i installed a hose clamp. On top of cleaning up the engine bay, this will also keep oil out of the intake and relieve crankcase pressure. I have some driving to do to verify this modification, so let me know your opinions.

Good Luck.
Let us know it works out for you after you replace your engine gaskets and seals.
That valve is part of the crankcase ventilation system and needs to be there.
It has nothing to do with emissions or turbo.

You have to remember that this engine has a 17-1 compression ratio.
Lot of back pressure being made inside.
Tom
It's actually a 21.5:1 compression ratio.

Anyways; indeed, it doesn't have to do with emissions or turbo and is a necessary part.
Valve cover breathers are just that, for valve covers. Modern cars have breathers on the heads, without a PCV/CDR, along with a CDR/PCV that vents the crankcase.

Offline thelincolnguy

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Re: 6.2 diesel cdr valve
« Reply #9 on: January 20, 2016, 04:30:20 PM »
Ok with that said, how can i run the cdr wihout it connected to the intake? To keep oil out of it. Iv heard of a draft tube. How does that work?
Thelincolnguy

Offline TGPJr

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Re: 6.2 diesel cdr valve
« Reply #10 on: January 20, 2016, 05:02:06 PM »
HA
"17-1 compression ratio".

K20 Detroit
Your right! I was thinking of something else. Regardless Just trying to.
make a point,.
Lincolnguy
Some oil in the intake is normal for this engine.
However if it's excess to the point it's running out(leaking)
The engine is tired.
Tom
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Offline hatzie

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Re: 6.2 diesel cdr valve
« Reply #11 on: February 16, 2016, 03:19:26 AM »
The CDR is a Diesel PCV for the 6.2L 6.5L diesel. 
It needs to be replaced @ every 30,000 miles.

If the hoses are soft replace them with some new SAE J30R7 hose.
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Offline K20Detroit

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Re: 6.2 diesel cdr valve
« Reply #12 on: April 30, 2016, 12:05:09 PM »
I decided to clean my CDR, I don't have the extra cash to replace it at the moment as the truck needs other things.

I took it off, brought it in the house to the kitchen sink.
I started off washing the outside with Dawn dish soap and a dish scrubbing pad.
I washed it off with warm water. Didn't come out new looking, just got rid of the surface oil.

I then sprayed water in the inlet, not too fast to avoid damaging the diaphram.
Old, sludgy oil came pouring out. I dripped some Dawn inside, added warm water, gently shook it, and poured out a lot more sludge. I repeated this, then switched to the outlet side and did it there as well.

One of the ways, water will flow after a little pressure. The other way, it simply won't flow at all if I remember right. For a little bit, I let warm water and Dawn flow through the valve, until it ran clear.

After that, I scrubbed the hose fittings very good with Dawn. Then, rinsed it all throughout until I knew the soap was all out.
The hardest part, really, is turning it just right to get the water out.

I did that two weeks ago - the CDR has been working great.