Increased oil consumption

[Oblin Goblin]

So over the last 20k miles or so my Banks turbo 6.2 Blazer has gone from using a quart of oil every 1500 - 2000 miles to a quart about every 1000 miles. Any ideas what the reason for this might be? I haven't done anything except advance the timing a little in that time. Do I need a new CDR valve perhaps? Or could this just be the begining of the end for my 275k mile motor? Everything else seems fine besides the increased oil use. Thanks

[john8662]

Could be a faulty CDR valve, although they rarely have problems.

Usually oil consumption goes up when you get external leaks.

One possibility could be that the turbocharger itself needs seals and is blowing oil into the intake. You can find this by removing your intake chamber and having a look. If you can really find thick deposits of oil in the intake, this could likely be your problem. Some oil is going to be normal though, because of the blow-by fumes going into the intake.

Still, with the miles you have on the engine, 1 quart in 1k miles really isn't that bad.

[doncannon]

hi oblin,

I agree with john. I found my return line leaking from the turbo to the adapter at the block (where the hose connects the two). To check this leave the engine idle when you return from a test drive for about five minutes. It helps to throw a piece of cardboard under the truck to see if it is leaking and where. mine would run back the oil pan and get on the exhaust pipe. the last time it just ran down onto the front crossmember (the one under the engine). Did you replace the rear main seal? I had to just after I put the turbo on (yes someone on the dp advised me to and I did not...don't you just hate when someone is right<thank guys>) Also the cdr was not connected on mine so i cannot help there i plugged the holes, but the breather right below where you put the oil in was left off and it seemed to use a little with that just vented to the atmosphere. Now it is connected like it should be to the banks air cleaner and it seems to have stopped the oil consumption.
hope this helps,
Don

[Oblin Goblin]

Well I just checked the turbo and it seems to be in perfect condition, so I guess thats not it. The motor has always leaked a little oil, but not that much, barly enough to leave a spot on the ground, so I know thats not where most of the oil is going. I may replace the CDR valve, although from what I know about how that works, I'm not sure the CDR valve is going to effect oil consumption that much.

[Hansh]

Is it leaking or burning oil? Is there pressure or blowby at the CDR or oil dipstick openings? If blowby or pressure problem then possible rings or cracked piston.

[Oblin Goblin]

A little oil is leaking from the drivers side valve cover, but not much. It lands on the exhaust crossover and burns off before it gets on the ground. Not pressurizing the crankcase either, I checked that.