duramax problem

[78repowerwagon]

What is the oil separator on a Duramax? I have a friend with 50,000 miles on it when it started blowing oil out the blow by pipe. The dealer said it had a blown head gasket. When they got the truck in they said it needed a new motor because it had blown the rings or burned a piston. Now they say it has a hole in the diaphragm on the oil separator causing the blow by. What is the purpose of an oil separator and how can it cause blow by?

 

[Diesel Freak]

This is just a guess, but the oil separator may be just a labrinth on the crank case vent.

 

[Alan Reagan]

It's probably a membrane device to keep oil out of the blow by system. Kinda strange that it has all of the symptoms of a blown head gasket, burned piston. Who is diagnosing this thing? Seems like a compression check would have eliminated those things.

 

[78repowerwagon]

It is pumping oil out the tube so bad it is basically undriveable-that is major blow-by! The GM dealer has it and they supposedly have a duramax tech. The service manager did not know what the oil separator is either.

 

[Roger rodbolt]

78repower,

Is this the same Duramax guy that had the transmission fallout? Like a Rock... ... .....

 

[Gary - K7GLD]

Just to keep things in perspective - one fella in this group lost an engine with only 14,000 miles on it - andother guy with an '03 lost his auto transmission with only about 900 miles on it... stones, glass houses and all that...

 

[78repowerwagon]

Yes, It was getting hard to get in gear, chevy told him the clutch was going out. He went in for it to be fixed and they found the trans was coming loose from the engine. They ended up putting in a new trans at some point(different problem).

 

[Alan Reagan]

Hey, Gary, I do try to keep these things in perspective. It's after I read the Duramax factory tour hype about them not having any problems with that engine that stirs me into a heated response when I hear someone really has a problem. Make sense? I hate to hear about the Cheb guys getting screwed around. That ultimately affects the acceptance of all diesel pickups and drives the value down. Like when they converted the gasser to a diesel engine in their cars and light trucks back in the 80s. The two times I've tried to talk to Duramax owners "at the pumps" I was shunned like an Amish boy with a nipple ring. They apparently didn't want to talk to a non Duramax owner. When they get over that complex, maybe they will get real help solving their problems.

 

[Gary - K7GLD]

"I was shunned like an Amish boy with a nipple ring. "



HEH-HEH-HEH - I like that!



Yeah, I know what ya mean - just don't want US to turn into "them"... .

 

[Swayse]

Dmax

It goes both ways at the pump. I try to make eye contact to strike up a conversation, the Cummins guys and the PSD guy just kinda nose up at us poor old Isuzu guys. So if you see a single cab GMC with the Duramax emblems taken off and Isuzu ones in there place, after market wheels with BFG AT KO 285 75 16 and a sticker on the back window that says "You wouldn't understand!", that's me. And, I'm not flirting, I'm just trying to get your attention so I can talk about your cool diesel.

 

[Alan Reagan]

Good enough, Peter. I had an interesting conversation with a PS guy yesterday. He has one pulling pinestraw with 150K miles on it. Loves the truck. Wants a Cummins for a second puller. Said he looked at the Cheby but 47K was too much. Can't argue there. He seemed nice enough and followed me for 70 miles into Savannah.

 

[78repowerwagon]

Well the new oil separator is installed and was picked up on Thursday the 14th. They had it three weeks. Drove the truck about 80? miles and had to add 6 quarts. Took back to the dealer and now they say it needs injectors. By the time he arrived at the dealer it had no power, 10 psi oil at 70mph 0 at idle.

 

[Alan Reagan]

Ouch. What do they think is happening? Fuel washing down the cylinder walls diluting the oil? It's interesting on the oil pressure. When I went home this weekend, a buddy of mine that's in a big hunting club up in central Georgia was telling me that one of their members who has a Dmax/Chevy had lost oil pressure on his. Since they were at the camp, no one had tools to check mechanically to see if it was just a bad sensor. Guess I'll find out next trip home.



BTW, What did the oil separator turn out to be? What does it do?

 

[78repowerwagon]

The GM dealer can't answer any questions. After questioning about why its doing it how its happening and what actually started the problem they finally said "we called GM tech and they said put injectors in it". They went on to say that the duramax was having alot of problems with injectors.



The oil separator is a little plastic black box on the front right of the motor. It has one inlet and two outlets with a oil resistant screen separating the outlets. Blow-by comes in the top and down, air goes through the screen and out the vent, while oil hits the screen and goes out the other outlet and back to the motor. Now the funny part, he was dumping oil out the blow-by pipe so fast he could not drive the truck without carrying gallons of oil with him. They replaced the oil separator because they thought the diaphragm(screen) had a hole in it.

 

[Pit Bull]

Originally posted by Alan Reagan



The two times I've tried to talk to Duramax owners "at the pumps" I was shunned like an Amish boy with a nipple ring. They apparently didn't want to talk to a non Duramax owner.

I never get a chance to talk to them at the pumps. I fill-up over with the big rigs at the high capacity pumps