Does anybody know if there should be any type of rubber on one or both sealing surfaces of the CDR valve? There isn't any on mine, and it's using a good bit of oil. ('84 6.9) I've soaked it in gas for quite some time, and the diaphragm holds a vacuum when one is applied to the small vent hole in the back. The cylinder compression is passable, and there are no oil leaks to speak of. I do have puffs of blowby from the oil fill tube, and one cylinder is whooshing through the intake - I'm getting ready to pull the valve covers and investigate that.

Any thoughts?

 

Hey Roycec, I cleaned mine and it took my oil consumption away. Some suggest replacing it at $90, but I think it can be cleaned if the inner mechanisms (seat, spring, diaphram) are still good. The tiny hole in the "can" of the CDR valve is for pressure equalization, and allows the inner diaphram to modulate. There was a rubber grommet on the upper intake side of the CDR valve pipe on mine. The portion of the CDR valve that goes into what appears to be the intake lower end (verticle pipe) was a tight fit, and I do not remember a gasket. Either way, both sides of that valve should be tight. (Just a thought)- I have questioned the practice of enlarging of the "soup bowl" for more power in previous threads because I felt that the reduction of negative pressure in that portion of the intake would adversely affect the operation of the CDR valve. You might want to check your model to see if the soup-bowl on the air filter has been modified. I hope this helps you, please let us know how you make out.

 

Thanks.

Was the seat on yours metal to metal, or is was there rubber to help it seal? Mine has two grommets, and both are there - snug and pliable.

Interesting thought on the soup bowl. Higher velocity, lower pressure, good ol' Bernoulli. Almost seems like the CDR spring could use a slightly lower rate, if the velocity by it was reduced. I was considering removing the soup bowl myself. Once I get this oil consumption thing under control, I may have to do an experiment. My current air cleaner housing could use replacement, and I could try removal of the soup bowl first. Of course to be truly controlled, the CDR valve would have to be replaced at 90 odd dollars...

Then again, there are plenty of guys running without the soup bowl, and even with higher flow intakes. I wonder how many of these are running turbos? Too many variables too early in the morning...

 

Roycec-I don't remember, but now that you mention it, it probably had a grommet on the lower side as well. I would think that on a turbo the CDRV would have to be on the negative side of the unit. I thought about adding an electric turbo to the filter housing, but that would negate my CDRV. Hopefully, someone else will chime in here. Have Fun.

 

Yep, wouldn't want to put boost on the crankcase.

I drove it today, with a full load of tools, and 5200# in tow, but forgot to check the oil while it was hot...

Where in VA are you?

 

Central VA, Charlottesville

 

what is the CDR valve? I have a problem with oil consumption also maybe this is the problem. Is it the big round Grey thing on the back of the intake?

 

Travisg96- Yes, that is it. The CDR valve is essentially a PCV valve and regulates pressure within the crankcase. CDR stands for "crankcase depression regulator". We have discussed this here on this site, and I will try to find the thread. I've been told that there is one way to check it, but depends on the rings to be operating properly.

There is always pressure in your engine and your CDR helps regulates it.
When it is bad (allows to much flow) the oil vapors and oil is sucked up and into your intake, or it can be restricted and cause excessive pressure and blow out of your oil seals.

 

travisg96: Yep, pretty common cause for oil consumption - lots of info in the forums.

fjb2c: I'm in Buckingham County, and travel through Charlottesville pretty regularly. Know anybody with the equipment to do dynamic timing on these things, (preferably luminosity?) Nobody around here seems to have working diagnostic equipment for IDIs anymore. I've always done all my work myself, but could bend the rules a bit given the cost of the old MT480s.

 

So i am replacing a head gasket on my 6.9 at the moment ant the rubber gasket in the valley pan is hard. can I get a new rubber grommet or is the only way to fix this to get a new intake gasket. Really would like to just reuse this one it isn't mangled to bad the sheet metal is just bent a little.

 

I've never tried to buy a grommet. If you go to Ford, though, take the part number off of your old CDR valve. My local dealership didn't even know what a CDR valve was. It's listed as an adapter of some sort, and I forget exactly what they call it...

 

Do you think if I put it back together without it or sealed it with RTV it would work? I am not trying to be cheap but I am not working right now and after replacing a head, injectors and glow plugs I really don't want to go spend another $80 on a new intake gasket if it can be reused.

 

Man, I know where you're coming from. I've just put a bunch of money into mine, too.

Are we talking about the intake gasket, or the CDR grommet? I've never tried to reuse an intake gasket so I can't give any kind of informed answer on that one, but I wouldn't be above using a little RTV on the CDR grommet...

 

I am talking about the CDR grommet. Just talked to international parts and they say their engine is different and I need to call Ford. There is a hole on theirs also but it just has a plug in it. The International 6.9 vents to the valve cover like any ormal engine would.

 

Roycec: I'm a Buckamite as well, travel up 20 quite a bit. No, I don't know of anyone with the equipment, and I do all of my own work-if I can.