Please Help. CDR test results.

[drocker]

Okay here is the deal. I have been losing oil out the dipstick tube. Now it doesn't gush out but you can see it trickle past the dipstick. I finally had a warm day to test the CDR. With the clear tube hooked up to the dipstick tube, I get bubbles in the water jug at idle. At 2000 rpms, still have bubbles. Not more not less than at idle. When I remove the CDR from the valve cover, the bubbles stop right away. I would assume due to least amount of resistance. With the CDR hooked up, there is air coming out so why is there back pressure at the dipstick? I can blow through the CDR valve from either direction and if you suck on the turbo end, cap the intake side and plug the pin hole on the back, the diaphragm will stay closed. What the hell is going on? Do I have a hole in piston or bad rings? I just turned over 150,000 miles on Sunday. I am just about to remove the CDR and vent to the atmosphere with an intake cover style breather element. I will be doing glows and injectors at the end of the month, I guess I could do a compression test then (not thrilled though). The two previous owners took very good care of this thing. First owner took the thing to the dealer for all maintenance so I don't think the thing was ran like crap. New CDR on order and will be installed Friday. Will test then again.

Please help. This is driving me nuts.

 

[Anubis]

I would do a compression test while you got the glows out.

well , never mind, see you got it planned.

 

[ak diesel driver]

have you checked the tube going from cdr to turbo for plugging or restriction. not likely but worth a check.

 

[drocker]

^ With CDR hooked up to valve cover, there is air coming out during idle at the tube that goes to the turbo intake. This is what is baffling me. If air is coming out, why is there air pushing oil out the dipstick tube. Unless I have that much back pressure. But like I said with the CDR pulled from the valve cover, there is hardly any air coming out the hole on the valve cover. I know with my intake that I put on, the hose to from the CDR to the turbo intake is reduced down to about 3/8 or 7/16 inside diameter. Maybe this is not allowing enough air to be pushed through. Any thoughts?

 

[bison]

By what your said you did and checked ,you should not have dipstick air.
The mess filter in the valve cover just below the CDR could be plugged with carbon deposits.

 

[ak diesel driver]

it almost sounds like your cdr tube is post turbo instead of pre turbo.

 

[drocker]

This is my air intake setup. The tube going into the intake tunnel is where the reducer is at. This is at the end of the goodyear hose in picture. It looks by the picture that it reduces from 1/2 down to 3/8 or even 1/4. Like I said, I wonder if this reduction isn't helping matters any.

 

[ak diesel driver]

that could be some of it. I also wonder if that close to the filter if it loses some of the vacuum it needs. If you still have your old airbox put it back on and see if it helps.

 

[drocker]

^ I will try that then too on Friday. I will also see if I can clean the mesh screen under the valve cover. When I do glows and injectors, maybe I will pull the cover and add new valve cover gasket. Already did the driver side.

 

[bison]

This is my air intake setup. The tube going into the intake tunnel is where the reducer is at. This is at the end of the goodyear hose in picture. It looks by the picture that it reduces from 1/2 down to 3/8 or even 1/4. Like I said, I wonder if this reduction isn't helping matters any.

I think the CDR inlet at the filter is in the wrong place,on the stock setup it is right above and in front of the turbo.It was placed there for a reason. With your higher flow filter coupled to the small 1/4 hose barb there is possible no vacuum at al at the CDR me thinks.
You got prob better result venting to the atmosfeer with a full 1" hose

 

[JMJNet]

bison have good point. It should have sucked in by the turbo not the air filter.

Although, it should be sucked in by the turbo but at that location, who knows which direction it will go.

Did you check your filter to see if there is goop of oil plugging it?

 

[drocker]

Update: I will be picking up the CDR tonight and I have the parts needed to increase the size of the tube going into the intake. It will be 5/8 diameter now instead of 1/4 or 3/8. After I get the parts intalled, then I will retest the CDR. Just picked up a injector socket for $50 as I will be doing them soon. Some good news is that my old job called me back but as a contractor (Manufacturing Engineer at local aircraft company) and I start March 1st. Been laid off now for 6 months so this is a relief. Thanks for all your help. I will post results later Saturday.

 

[guybb3]

Some good news is that my old job called me back but as a contractor (Manufacturing Engineer at local aircraft company) and I start March 1st.

Kansas? The old Beechcraft company?

 

[drocker]

^ Nope. I worked for Cessna. But Hawker Beach (Beechcraft), Learjet and Spirit (used to be Boeing) are all right there as well. In fact I have worked for all of them at one time or another. Pay is good, but many layoffs.

 

[drocker]

Well I replaced the CDR, enlarge the tube going to my intake and moved it closer to the turbo. Guess what? It works like its supposed too. Did the CDR test and no bubbles and it pulled up almost 3" of water at 2000 rpms. First photo shows the new reroute. 2nd and 3rd photos show the before and after I enlarged the nipple going into the intake by the turbo. If you scroll up, you can see the old setup. This really relaxes my mind now that I know that there is no internal damage to pistons or rings. Now I will watch if I loose any oil now. Thanks for all the chimed in with their ideas.

 

[buddy]

good work. that reducer is likely the main problem from before. If you still have oil at times of high load, it is becuase the CDR closes with high vacuum, as its supposed to. And so at high load, for a long hill or something backpressure can build and push oil up. this is why I added a breather, because I often push my truck up long hills at way too fast speeds

There are also differnt CDRs, that look the same, for N/A engines that close at lower vacuum, so would cuase more pressure at lower loads.

 

[ak diesel driver]

Hmmmm this makes me wonder if I couldn't insatll a valve on my CDR tube and restrict it slightly to reduce my oil consumption. I could just keep opening or closing the valve till I found the sweet spot.

 

[buddy]

To reduce oil consumption should try that provent which would collect the oil and you can return it.

 

[ak diesel driver]

I just have a hard time spending that much for a piece of plastic. I probably should tho

 

[drocker]

This Yukon will probably never tow anything anyways. I wonder, though, if this will help the MPG I am currently getting with the reduced back pressure. Right around 14.5 MPG is all I am getting. Like I said earlier, I will be doing glows and injectors soon. Trying to convince my wife the benefits of 4" exhaust. I hope with the summer blend diesel and 4" exhaust I can hit at least 20 to 22 MPG.