:help2: My truck has a bad Crankcase Depression Regulator (CDR) and I am trying to figure out how much this affects the vacumm pressure in regards to the turbo. It seems as though my turbo is not kicking on as quickly as it should or use to. The service engine like comes on but only stays on most of the time when you are running over 2K RPMS. When we hooked the scanner to it (two months ago) it said something about the vacumm lines and when we looked there was a line that wasn't hooked back up correctly (the dealer that put my new injector pump disconnected it). But we haven't put it back on the computer yet. Just wanted to see if any of you knew more about this CDR and if it affects the vacumm pressure and turbo.

:thankyou2

Don't confuse the CDR vent with the WG solenoid/vac pump for the turbo. Since you have a mechanic at your service, have him make an adjustable waste gate controller (very simple, a threaded bolt, a nut and a spring) or buy Heath's TM.
The vac system is a hassle to keep up with and you can take it off with a spring on the WG and put a 30mm shorter belt on instead of the stock 61010 run the 61000.

With this waste gate controller you are talking about this elimanates the vac pump - how the heck does that work? Please give me more details.

I do know that my CDR is bad though it is throwing oil in my turbo, so it has to get replaced.

I just got done speaking with someone and they told me that my CDR Never goes bad and that is their is oil in my Turbo that is is normal. Is this true? I don't want to buy a CDR if that is not the problem. Anybody have any input on this? Thank you

Diesel Chick, before replacing the CDR, clean it. Take it off and soak it in clean diesel fuel, then try and get as much of the oil and fuel out of it as possible. Don't use any compressed air, just drip dry and invert. The CDR's accumulate oil inside over time and then tend to keep adding oil to the intake. ;) Also, hook up a boost gauge, even if it is a very inexpensive temporary gauge and monitor your boost pressure. I think you will find your engine isn't making much boost, but only way to fix propperly is to know what it is actually doing. With that information along with the trouble codes set repair should be easy to diagnose.:grd:

Just as a thought - if my engine isn't giving a lot of boost what would most likely cause that?

I just got done speaking with someone and they told me that my CDR Never goes bad and that is their is oil in my Turbo that is is normal. Is this true? I don't want to buy a CDR if that is not the problem. Anybody have any input on this? Thank you
oil from the CDR is normal on a 6.5L td. If you remove the vvalve cover and look underneth it has a wire mesh condensor screen. Clean it real good of oil buildup and seal the aluminum parts of the intake side of the turbo, it will almost stop it from leaking.

The CDR isn't there to prevent oil from entering your intake, it is there to reduce the amount of oil being sucked up but still maintain a vacuum on the crank case. All engines that have pistons or valves have s small amount of pressurised fumes that get by the seals. These fumes have to be vented out of the crank case. The best way to do this is use the vacuum on the intake to suck them out. But on our turbo vehicle there is a lot more vacuum that is needed so the canister closes of part way as the vacuum increases so you don't suck too hard on the crank case. There will always be oil vapors in the fumes comming out and therefore oil on the turbo. This was designed into the engine and its operation. The only problem is when the CDR quites working and closes of. Then the fumes build up and either blow out the dip stick tube or out the oil fill cap. On a locomotive you have to have a vacuum of at least 1"H20 or you can have an explosion inside the crank case. I don't think this will happen on out vehicle but I know a lot of fumes in the CC are a bad thing. If the CDR goes bad in the open position you just end up sucking more air than is needed, and more oil.

Just as a thought - if my engine isn't giving a lot of boost what would most likely cause that?Thats why I suggested the adjustable spring for the waste gate.
If your truck is an F engine the vac pump only closes the waste gate on the turbo, loss of vacuum or solenoid function negates WG and no boost builds. Springs don't fail once every year or two.

I just figured that out - I am just a little slow - I talked to two different people and got a couple different answers and started nervous that something was massively wrong with my truck - but I am definitely going to look into this whole adjustable spring. Thank you Thank you and Thank you !!!!!!

Diesel Chick

GMCTD has a thread in FAQs that fully describes CDR operation.

Turbine Doc - I read the info on the CDR which had given me the info needed to pinpoint that my CDR was bad - the only reason I went ahead and posted it was due to some information from a vendor I was talking to that was telling me that my CDR very rarely goes bad - though other vendors tell me this is something that does go bad that needs to replace once in a while. This same vendor told me that if fumes come out of your dipstick or oil cap that your engine was going bad not your CDR - but yet people are posting on here that these are signs that your CDR is bad. I just wanted some back up verification. Thank you

Oil vapor out the dipstick tube is ok as long as it's not excessive or liquified.

I have a steady flow of vapors that comes out of my oil cap when the truck is running - I didn't see what it did if I took out the dip stick but I am not getting any large amounts or anything abnormal in that catergory. The idea about the turbo getting some oil in it is understandable but it is also going into my air filter which is not very helpful. That is the reason we believe need to replace the CDR. All the signs seem to point to that directions - Am I correct?

No, The cdrv just has to sit there, working or not, and let the vapors into the intake stream. You're just noticing an accumulation of oilvapor and silicates in the intake airbox. Clean it all up, seal the turbo if it's leaking and go with it.

If you simply wash the CDR and get in the habbit of washing it every 20,000 miles or so you will get rid of the accumulation of oil in side of the CDR and get it back to just letting the vapors pass through. After a good deal of time, vapors will leave behind solids and hence the reason for cleaning the CDR. As far a vapors coming out the oil fill tube, this is normal, the question here is how much. A small amount is fine. A cloud of smoke/vapor is cause for concern.;)

The amount of oil drawn through the CDR tube will vary with the condition of the engine and the amount of blowby past the rings. The greater the pressure in the crankcase and the more vaporized oil in the "air" the more oil you will see.

I would suggest checking the vacuum wastegate system out for proper operation, and stick with it...