I got to go to the junkyard Sat. morning,(my wife let me),and scored a CDR, air cleaner ducting, and a jack& handle. I've been running this truck for a year and 1/2, and it's always had a blue haze from the exhaust. Unknown history, other than the PO said it had 260k when I bought it. I,ve read on here that said the CDR wouldn't fix blue smoke, that that had to be blow-by. But for 3$for a used CDR, I figured WTH. On my way to & from work today, I drove it pretty hard, no blue smoke, some black smoke. So maybe there is still life left in the old truck yet! On another note, after installing the missing air cleaner ducting, the temp guage went down 1/4" on the guage, so it,s liking the colder air. Thought I'd share.
CDR cleaned up the blue smoke
- Thread starter grog85
- Start date
damac
Full Access Member
We started with a fresh one on our clunker a few months back after reading about what they potentially can do if not working right. To me its a better piece of mind to start fresh and service them rather than an old one.
Cheapest place I think is at the url below. They have a slightly newer better design now, the can, a bushing between it and the intake, and a single piece of rubber that goes from the cdr into the engine.
http://www.trademotion.com/partlocator/index.cfm?siteid=214072
Watch out for the old parts, the old piece that goes into the engine can crack easily letting pieces go down inside. I layed a moving pad over the engine and lay in it and took my time piece by piece.
Cheapest place I think is at the url below. They have a slightly newer better design now, the can, a bushing between it and the intake, and a single piece of rubber that goes from the cdr into the engine.
http://www.trademotion.com/partlocator/index.cfm?siteid=214072
Watch out for the old parts, the old piece that goes into the engine can crack easily letting pieces go down inside. I layed a moving pad over the engine and lay in it and took my time piece by piece.
plywood
Recovered N/A
By replacing it with a used one you may have a better or worse one. Kind of hard to draw a conclusion.
Also seems funny you dropped a 1/4" on the temp gauge from intake air ducting, although if so that could explain less blue smoke.
Also seems funny you dropped a 1/4" on the temp gauge from intake air ducting, although if so that could explain less blue smoke.
Reconnecting the cold air intake tube isn't going to effect oil consumption, it will drop temps though
damac
Full Access Member
1. For some reason that site does not list the parts by # on my old order so I cannot tell you the part #. But they are just a reseller for ford parts, it just happened to be the cheapest price to my door at the time.
So you will have to search on this forum for the cdr part numbers. The main cdr unit, a small rubber bushing that goes on the cdr where it meets the intake. Then the long round piece that goes from the cdr to the engine hole. So 3 parts. The expensive cdr and the other 2 parts are less than $10 each.
2. Since it has been colder around here I have had the stock air scoop disconnected and the hose just dangles near the steering pump. After everything I have read and considering my limited fabrication skills, I think the best thing for us newbies to do is buy the hypermax cowl induction intake straight from them. Less than $100 to your door and some improved airflow over stock can only help. I have read they may introduce a wierd noise but I don't care, our truck is a hauling beater for toys not a daily driver
So you will have to search on this forum for the cdr part numbers. The main cdr unit, a small rubber bushing that goes on the cdr where it meets the intake. Then the long round piece that goes from the cdr to the engine hole. So 3 parts. The expensive cdr and the other 2 parts are less than $10 each.
2. Since it has been colder around here I have had the stock air scoop disconnected and the hose just dangles near the steering pump. After everything I have read and considering my limited fabrication skills, I think the best thing for us newbies to do is buy the hypermax cowl induction intake straight from them. Less than $100 to your door and some improved airflow over stock can only help. I have read they may introduce a wierd noise but I don't care, our truck is a hauling beater for toys not a daily driver
plywood
Recovered N/A
Well, I agree it could drop the temp slightly, very slightly, but dropping temps by some percentage will lower oil consumption, very slightly also I suppose.
I'm just wondering if he replaced a dirty air cleaner while doing a few things at once or maybe forgot to put it back in
I just still don't believe a bad CDR can cause oil consumption on an otherwise 100% healthy engine, other than possibly at real high rpms.
I'm not God, could be wrong, and I've seen many opinions on the purpose of it, just like the soup bowl, but I believe it simply makes sure that pressure in the crankcase can vent into the intake but that there can never be more than a slight vacuum on the crankcase from the intake.
Honestly, in all the quadtrillion posts I've read here and elsewhere I can't remember a legitimate claim that made me think the CDR stopped or reduced blue smoke, and I've been waiting for some time.
All due respect to the OP, just my dissection of the evidence.
I believe this is the Ford part number for the valve E3TZ-6A665-A.
The air cleaner is still in place, and in good shape. The truck did use oil,1 quart in 4-500 miles. So it will be a couple of weeks before I can report if it did make any difference on consumption, but it did clean up the blue haze.
f-two-fiddy
Registered User
I think You Guys are over emphasizing the importance of the CDR. It's just a tube connecting the crank case to the intake.
Replacing it is not going to change oil consumption.
Replacing it will clear the blue haze, until the bottom of the CDR fills with oil again. Then Your back to where You started.
In normal operation, the diaphragm will NEVER move. Hook Your vacuum pump to the intake side, and see if You can get it to move. It'll take more vacuum than the pump could EVER produce. It's a safety device to prevent engine run away. In theory, the engine could suck oil out of the valley. How that scenario would ever come to pass, is beyond My capability.
Engine upside down while running???
Replacing it is not going to change oil consumption.
Replacing it will clear the blue haze, until the bottom of the CDR fills with oil again. Then Your back to where You started.
In normal operation, the diaphragm will NEVER move. Hook Your vacuum pump to the intake side, and see if You can get it to move. It'll take more vacuum than the pump could EVER produce. It's a safety device to prevent engine run away. In theory, the engine could suck oil out of the valley. How that scenario would ever come to pass, is beyond My capability.
Engine upside down while running???
plywood
Recovered N/A
I've been tossing around the theory that if there are bad gaskets such as the valve cover or the grommet around the CDR allowing air to flow into the crankcase that the vacuum would pull air through the CDR so fast that it would cause some excess oil migration into the intake.
Actually the CDR varries the size of teh opening to regulate the pressure in the crankcase at different rpms hence the reason for it being called a crankcase depression regulator and not a crankcase depression closer, it will eventually close off if vacuum gets too high . THe CDR keeps the ventilation system on a constant push me pull you balance so that some pressure is maintained in the crankcase while a steady vacuum rate is regulated to keep gasses scavanged off without getting to the point of sucking oil out with them.
I've played with breather systems on a LOT of diesels and they all have a very delicate balance that can easily be thrown off by defective componants or even free flowing air filters that reduce manifold vacuum. I've had to make custom oil traps for some to compensate for the air filters( when teh vacuum drops pressure rises in the crankcase and soon they start belching oil , too much vacuum and they start drawing oil, it's a delicate balance that has to be maintained) Older systems came with a factory road draft tube, but the hose size was significantly larger than the opening on a CDR and in contrast a factory RDT system depended on vacuum created by passing road air so it was kept far more open so pressure couldn't build and gases could easily escape on their own
I've been tossing around the theory that if there are bad gaskets such as the valve cover or the grommet around the CDR allowing air to flow into the crankcase that the vacuum would pull air through the CDR so fast that it would cause some excess oil migration into the intake.
Correct in a way. Anything that changes the system vacuum will alter the flow rate and mess things up
plywood
Recovered N/A
So hypothetically, a CDR could have a weak spring causing it to close too easily which would seemingly not cause excess oil consumption.
If the diaphram was damaged, that would cause it not to close and in a way I can see that causing excess oil consumption if there were other issues such as a real bad valve cover gasket or something allowing air to be sucked through at high speed, drawing some oil with it.
I guess what I'm saying is that small amount of vacuum on the crankcase can't draw air or gases in through piston rings or exhaust valves enough to cause a high rate of flow. If there was a breather say on the valve cover, then that would dramatically change the situation.
Blowby is being produced by somewhere around 400 psi of compression, so I don't see how there can be any more blowby then what is produced by compression, not sucked by maybe 1 in lb of vacuum or something.
It just seems to me the blowby is what the blowby is, and that is directly related to how much oil consumption there will be.
What oil separates out of the vapor happens in the bottom of the valley pan, but I can imagine as posted that it may cause a short term reduction in blue smoke while the oil migrates up through the new dry CDR.
I don't even buy the theory that it would stop a runaway engine, I just think it dissallows excess vacuum on the crankcase in the event of a clogged air filter which could suck in a valve cover gasket allowing air to travel through the crankcase and thereby causing the runaway engine.
Totally open to pinholes or gushers in my theories.
If the diaphram was damaged, that would cause it not to close and in a way I can see that causing excess oil consumption if there were other issues such as a real bad valve cover gasket or something allowing air to be sucked through at high speed, drawing some oil with it.
I guess what I'm saying is that small amount of vacuum on the crankcase can't draw air or gases in through piston rings or exhaust valves enough to cause a high rate of flow. If there was a breather say on the valve cover, then that would dramatically change the situation.
Blowby is being produced by somewhere around 400 psi of compression, so I don't see how there can be any more blowby then what is produced by compression, not sucked by maybe 1 in lb of vacuum or something.
It just seems to me the blowby is what the blowby is, and that is directly related to how much oil consumption there will be.
What oil separates out of the vapor happens in the bottom of the valley pan, but I can imagine as posted that it may cause a short term reduction in blue smoke while the oil migrates up through the new dry CDR.
I don't even buy the theory that it would stop a runaway engine, I just think it dissallows excess vacuum on the crankcase in the event of a clogged air filter which could suck in a valve cover gasket allowing air to travel through the crankcase and thereby causing the runaway engine.
Totally open to pinholes or gushers in my theories.
Well, if the spring was weak and it closed too easily chances are it would build excess pressure and belch oil, but essentially you have the idea. When pressure gets too high in a crankcase, oil vapours begin to bind together into larger drops just small enough to pass but not heavy enough to collect and drain down. and if too much vacuum shows it will create a draw point that tries to siphon off whatever oil is getting near the opening. That is why it has to maintain a balance.
I studied the snot out of this stuff coming up with a custom oil trap setup for the first diesel car I ran across that started eating oil after putting a free flowing air filter on , then shortly after found that Racor had a real nice oil trap they sell that helps modified systems or older worn systems
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