start wil an oil change and keep an eye on the level better to feel the oil between finger and thumb to see if there is fuel in it than smell it can be hard to smell pcv valve mabe could be excessive blow by

 

Pull dipstick out and put drop of oil on paper towel. Does a ring form around the oil?


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I dont think so, but heres a pic

and here is a pic of the leak

what do you think?

 

Mine was doing the same thing when it make making oil....

You best bet is to drain the oil and see how much comes out. You should get 10QTS of oil.

You'll need more oil on the paper towel to see if its making oil.

 

I ran into this on an lb7 just a short time ago. I changed the PVC valve which actually is a little rubber diaphragm that looks like a carbureators accelerator pump. It's located on the drivers side valve cover. It's held down by 4 Phillips head screws. Only takes about 5-10 minutes to change. It's cheap and easy. I would do an oil change and change the pcv and then monitor it.

 

Do all LB7's have PCV's? This is the first time Ive heard this about LB7's

 

I believe they all have the PCV system no matter what emission level the truck is. The one I was working on was loaded with all the emissions crap and it had one. My 03 doesn't have any emissions stuff on it (from the factory) and mine has one. All engines have a PCV system as far as I know.

 

Huh... Guess you learn something new every day......

 

Thanks for the replies! Tomorrow I will hopefully change the oil and check on getting a pcv valve. It is not a California emissions truck.

 

Call the dealer. Its may be available aftermarket at napa or something, but I would go to the dealership and get one even if it was available aftermarket. JMO

 

I didnt get a chance to check on the pcv valve, but did change my oil. didnt get to measure how much came out...I was in a big rush. I really dont like using napa parts for anything. never good luck haha, Im sure i can get a gm one from our other gmc dealer.

 

any luck? i have a similar problem.. did you discover a bigger problem?

 

betting it was the injectors were bad.

 

It wasn't injectors, I measured all the oil that came out of it, exactly 10 qts. I haven't done anything with it yet because its not leaking much. I suspect pcv valves but haven't changed them yet

 

Alright, let me know if it fixes it when u get around to it. I also have oil in my turbo manifolds and exhaust. I haven't checked for fuel in oil yet, but I suspect my problem is bigger than yours haha. Just trying to start with the simple stuff. I got my EFI v2 this week so when I get my truck back this weekend Im gonna check balance rates and change the oil. I'm thinking my crank case is over full, causing it to vent and run through my turbos.. Praying I find a problem before I get down to piston rings.

 

Rings won't cause the crankcase to be overfull. Hopefully it's something easy for ta


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I have a 01 and mine leaks a very small amount of oil out of the same tube, but i was under the impression that people with newer model trucks re route their PCV so this wont be going back into their intake?! correct me if im wrong

 

You are correct, mine also vents to the atmosphere. I'm not sure if they started doing that with the LLY or when they started putting emissions bs in the LB7. Either way ours don't do that. Mine just has way too much blow by out the bottom haha.

 

Mine does the same thing. It's normal to have a little bit of oil down there since it's basically a crankcase breather. Same systems are used on CAT generators and they roll some smoke and oil all the time. As long at you are pushing oil out of the tube, you should be fine.

 

Mine's a little excessive though. Plus there's oil in my turbo manifolds.

 

Checked mine and no oil in the turbo or intercooler pipes and it just barely comes out the lower tube, hope ya find the problem and it's not too bad

 

Bump a old thread:

I have the same symptoms however I have a lot of build up around the same area just covered in this mess.

Is the PCV Valve blocked causing the pressure to release above it? I attached a couple pics from how it looks at the valve.


Also My picture of the steering stabilizer is the same as the post prior. What was the final outcome? PCV Normal or replaced cleared it up?

 

There's actually one vent on each rocker cover and they tee together over the turbo inlet pipe before going into a tube in front of the right rocker cover.

 

I can see the vent from rocker cover however Passenger side is really bad but clean on driver side. However behind the alternator and above cp3 is just caked with this gunk, and the PCV is just nasty as you can see in the pics. I wonder if I replace the PCV it will fix this or at least clean it up.

 

Couldn't hurt! I'd clean it all off good with brake clean so it's nice and dry. Then change your oil and keep a close eye on it. Much easier to find the source if its nice and clean to start. There is a PVC breather on each valve cover but they both come together in the middle under the turbo inlet then to the passenger front corner where you see the mess. Take both hoses off at the middle and see if its just coming out of one side. If so then it's probably that vent valve. If its coming out of both then possible 2 vent valves (not likely) or excessive crankcase pressure.(blow by or fluid transfer causing overfill). That's where I'd start.

 

Time for a re-route behind the motor!

 

I found this diagram, is this the hose you are referencing to?

However in looking at the diagram I cant see the pvc breather you are talking about at each of the crankcase listed.

 

I found this diagram, is this the hose you are referencing to?

However in looking at the diagram I cant see the pvc breather you are talking about at each of the crankcase listed.

Yes! #13 & #1 come from each of the PVC breathers on each valve cover. I also wasn't able to find a part# for it but here is a pic.

The top cover is an lb7 and that little square thing in the center of the cover with the tube sticking out of it is the PVC breather. There's 4 screws in each one. Both rocker covers are the same.

 

I am on track now. I will look up part numbers on my diagrams now that I am tracking. Thanks for the help.

I am thinking if it is not this, and the hose is ok. My guess is the passenger side cover has a faulty seal leaking out all this gunk. Could that even be possible?

 

Yes it's possible. It's actually a silicone seal on the upper rocker cover. There are also rubber grommets on each bolt and a rubber gasket on the lower rocker cover that have potential to leak. Good luck. Glad I can help

 

Looks like #12, GM Shows it to be included with rocker covers. Not sold individually

012 97223559 COVER. Engine Valve Rocker & Camshaft
COVER,VLV RKR ARM(UPPER)(INCLS PCV DIAPHRAGM VALVE). Required: 02
COVER,VLV RKR ARM(UPPER)(v)8972235593(INCLS PCV DIAPHRAGM VALVE). Required: 02
For: C4,5 6.6-1 DURAMAX(LB7) (2003-2004) (2003 - 2004).
For: CK2,3 6.6-1 DURAMAX(LB7) (2001-2004) (2001 - 2004).

 

Ya I think you're right. You may be able to remove it and clean it. Also maybe find a used one. Isuzu uses the same valve on their small engines such as on whisper watt gensets and terex light towers. You may be able to source one directly from Isuzu or pick up a used one. I would run it with the 2 hoses disconnected to verify that is your source. Disconnecting these will not affect the drivability of your truck but it'll make a bit of a mess. Some oil is normal. Did you correct your oil level? Larger engines dump these hoses to atmosphere. Not emissions legal but is also another option. Just put longer hoses on and vent them to the ground behind the bell housing. For racing applications only... Of course