A couple 6.2 questions, help please.

[libtec]

Thanks for looking.
I'm trying to find the Crankcase Depression Regulator on my 90 suburban. I found a picture of it and a description of it's operation in the members resource area, but I can't find it anywhere on my truck. Can someone clue me in on where to find it? Was it standard on all 6.2's or just an item on trucks with certain accesories or emissions requirements?
My second question is regarding the three solenoids mounted on the drivers side of the intake. I crawled under the hood of another 6.2 after writing my post earlier and found the emissions sticker describing each unit and showing the line diagram, something my truck doesn't have. I've read that some people install an intake gasket that blocks the operation of the EGR unit, something I believe has been done on my truck by the previous owner. If this is true are any of these solenoids and associated lines of any use to the truck anymore?
Third question. Since a motor is nothing more than an over glorified air pump would there be any harm in freeing up how the intake breaths on a NA 6.2? In theory the small snorkle on the stock air cleaner can only let in a limited amount of air at any one time. Is it unheard of to add a second hole to the cleaner body to allow more intake volume at higher rpm's? If turbos are the norm rather than the exception then why not get the NA to breath as free as possible?
Final question. What is considered a normal amount of greasy / oily buildup on the inside of the intake mainfold? Mine has more than a film, more like a squishy layer 1/8 inch thick in places.
Thanks for any input! I really appreciate the sound advice this site provides. God bless.

[ 04-12-2005, 06:43 PM: Message edited by: libtec ]

[john8662]

On a 90 model suburban your CDR valve is mounted on the Passengers side valve cover. You'll see a 1" ID hose about 6" long coming off the intake manifold and directly into a "tuna can" that's connected to the valve cover. It's your "PCV" if you will, keeps crankcase pressure slightly negative to keep from blowing out your seals, etc. ALL 6.2's and 6.5's are fitted with them from factory, it's not an option rather a physical part of your engine.

The solenoid bank is for EGR, you'll get a code if you disconnect them on your 90 6.2, but they don't do anything for you if your EGR connection in the head is blocked by the gasket used by the intake manifold. This is a good thing to disable the EGR valve. What you might want to do to get the truck to breath a little better is replace the intake manifold all-together with an open plenum intake for the HD version of the 6.2 of your year. But you don't have to, the EGR C code 6.2 manifold in the 88+ 6.2's is less restrictive than the older 6.2's EGR manifolds were.

The hole in the air cleaner itself is small, but there isn't much you can do about it other than opening up the hole and fabricating a snorkle of your own. Banks makes a kit that does this for N/A engines, but is sold as a package with an exhaust system called the "Stinger" System. Dr. Lee aka "CleviteKid" made his own air cleaner setup and calls it "Swanger Air" you should check it out Here (http://www.imagestation.com/album/?id=4289701427&code=6361415&mode=invite) ! You can also search this forum and the "Ask Dr. Lee" forum for more info on this.

Basically you won't want to open up the air cleaner housing under the hood because you'll be allowing the engine to intake hot engine compartment gasses, negates the advantage of more airflow.

And finally, dirty intake? If you have a working or did have a working EGR system, thats what it does, it plugs up the intake. Thats a mixture of oil and diesel sut that mixes and sticks to the wall of the intake. It's normal, thats why it never hurts to kill the EGR stuff!

[ 04-12-2005, 07:06 PM: Message edited by: john8662 ]

[libtec]

Thank you! Talk about service! All my questions addressed within ten minutes of posting them. The link to Dr Lee's album was a real bonus, what a sweet looking truck.
Well it looks like I have a little more under hood learning time coming up soon, after which I'm sure I'll have more questions. Thanks for the help!