New to site, appriciate help.
My 1994 6.5 has suddenly started using a lot of oil. It has allways had blowby and does not seem to be any worse. In the past it used about 1 quart per tank of fuel. Now it is using about 3 quarts. It is not leaking and no oil in coolant so it has to be burning it? Does not seem to be smoking. Runs about the same. Could it be leaking in the turbo? Not really familiar with the turbo part of engine.

Thanks,
BP

Welcome to the site.

Your oil burning by what you say is either leaking past the turbo seals or the cdr valve is not working anymore.
These 6.5 are notorious for pulling oil over to the intake.

take the intake hose of the turbo, there is most likely a lot of oil there.

Grab the nut on the turbo vane and feel for sideplay, there should be very little and should spin freely.

Start the engine and look at vane if there is a oilfilm radiating outwarts from behind. If there is you look at a overhaul. Not that hard if you are mecanical inclined, lot cheaper too. DON"T STICK YOUR FINGER IN THAT HOLE

Then take the CDR valve of the valve cover, same side as turbo.

You can test that by sucking on the inlet or outlet port, I cant remember wich one , and than put your finger over the pinhole that is located on the backside of that can. You should be able to move the diafrahm inside.

On my 95 see sig I had the same problem, but turbo and cdr valve where ok.

I solved the problem by venting the cdr valve with a longer hose to the front and bottom below the truck, and plugged of the hole in the intake elbow with a plastic plug.

She don't use a spat of oil no more

Thanks for that info. I will try that Monday and report back.

BP

take a look a www.heathdiesel.com and look in the blog section. There is an article on testing your CDR valve.

Also take a look at your air filter. If its severely clogged it, the turbo may be pulling oil through the CDR valve.

Also an FAQ article here. The CDR will regulate VACUUM level. No vacuum available under the truck, unless you have a Hoover hidden somewhere under there.

CDR is taking advantage of pressure drop across the air fiter. More pressure drop comes from more air flow (more engine RPM). Taking the CDR out of the intake air system now means that you are running at minimum atomspheric or slightly higher pressure. CDR helps to keep a few inches of water column vacuum to help prevent oil seal leakage throughout other parts of the engine.

Read FAQ article for full write up and details w/pics.

I changed the air filter today. The old one looked pretty bad. Did the test on the turbo, no play in blades and no oil comming out front while running. There was plenty of oil in the tubes from the CDR. I ordered a new CDR. No need to do the tube and water test I have blow-by puffing out dip stick tube. I will post again after I install CDR and run a tank of fuel.

Thanks for helping,
BP

Might want to look at your upper and lower intake, mine was about 30-40% obstructed with oil-soot-crap, and I'm suspecting that I need a new cdr too. And I'm still cleaning out the intakes-No Fun!!:mad:

I changed the air filter today. The old one looked pretty bad. Did the test on the turbo, no play in blades and no oil comming out front while running. There was plenty of oil in the tubes from the CDR. I ordered a new CDR. No need to do the tube and water test I have blow-by puffing out dip stick tube. I will post again after I install CDR and run a tank of fuel.

Thanks for helping,
BP

a new cdr ain't going to solve the oil burning, all that blowby pressure will keep that cdr open and feeds that oil right into the intake.
Vent the thing to the atmosphere,and be done with it, or you look at rebuilding. If the bottom end is reasonable good , the seals wont leak.
Mine does'nt . ;)