CDR valve

[shane1raider]

Wow...just checked on a new cdr valve...103$. Is this really what they sell for? Also no one has it around this part of the world. My valve is really oiley on inside and around the cover..guessing I need a new one. Also things underneath the burb look really oily?

[a5150nut]

A little more information might help people here to help you. Year, miles, modifications, how long you have had vehicle, maintenance history?

Or clean it up real good so you can find where the oil is coming from.

Welcome to TDP.

[shane1raider]

99 suburban 1500, 300k+..only had it a year. Don't know much history on it. Since I've had it, regular oil changes,fuel add. Runs pretty good. Small vibration at low idle,and oil pressure near zero when warm.

[trbankii]

Wow...just checked on a new cdr valve...103$. Is this really what they sell for?

Rockauto has ACDELCO Part # CV916 (OEM) for $61.

[Kennedy]

The CDR is not really an active "valve" so to speak. It is an open chamber that is designed to close off IF there were ever excessive suction force applied. In operation it does nothing. Just connects the crankcase to the turbo. Replacing it will just get you a shiny new unit and no change in what passes through it.

[shane1raider]

If it won't change anything why do they suggest replacing it every so often? It does have spring and diaphragm in it. It functions somehow.

[DmaxMaverick]

If you have excessive blow-by, causing a really messy CDR, a new CDR won't change that, even if your old one doesn't work. As John said, the CDR does nothing, until intake vacuum becomes extreme. It's purpose is to prevent outside air (and dirt, moisture, etc.) from being sucked passed the engine seals. Removal of crankcase oil vapor is a byproduct of its design, not its intent.

A restrictive air intake system (plugged air filter, collapsed plumbing, pheasant stuck to the inlet (it's happened), etc.) can cause excessive oil vapor to be drawn from the crankcase.

[shane1raider]

That makes better sense to me. So should I replace it or am I just wasting money as my intake is free of pheasants:)

[sctrailrider]

I would clean the old one and put the 60$ somewhere else that might need it...

[DmaxMaverick]

As said, clean it, and go from there. If it's failed and/or deteriorated (rattles with obvious broken spring, missing parts, ruptured diaphragm), replace it. Otherwise, use it again.

[shane1raider]

So just pry the front rim up take it apart and wash it with dawn dish soap?

[DmaxMaverick]

No. Just soak and flush it. I use #2 or kerosene to clean it, then Dawn to clean that up. DO NOT use any chlorinated solvent or brake cleaner. It will dissolve the rubber. Don't take it apart, or you'll have to buy another one.

[shane1raider]

Sweet thanks dmax..I would have screwed that up.