6.5 blow by - Diesel Place : Chevrolet and GMC Diesel Truck Forums
 
Home Forum Market Place Garage Lounge (0) Tuning Library DTC Tool Register Vendors
Go Back   Diesel Place : Chevrolet and GMC Diesel Truck Forums > GM Diesel Engines > 6.5L Diesel Engine
Register FAQ Forum Rules My Replies My Threads Mark Forums Read Auto EscrowAuto LoansInsurance

DieselPlace.com is the premier Duramax Diesel Forum on the internet. Registered Users do not see the above ads.
Like Tree1Likes

Closed Thread
 
LinkBack Thread Tools
Old 10-05-2009, 10:55 PM   #1 (permalink)
wallybly
Diesel Head
 
Join Date: Dec 2008
Posts: 41
iTrader Score: 0 reviews

6.5 blow by

i have a 94 k1500 with 220000 on it and it just started having a little smoke hase blowing from the dipstick tube. it has had the injection pump done about 25000 ago new tranny and i also relocated the pmd. it has a bad exhaust leak on the crossover pipe from the driverside manifold to the turbo,i just ordered a new 2 1/2" pipe of ebay going to install as soon as possible. i just hope i didnt waite too long, ive been reading around on internat and cant really get a solid anser on my specific question. ive read so many things from head gasket to holes in the piston to injectors or even lift pump. oh i forgot to mention because of my ignorce with typeing that while idleing sometimes it will feel like the truck got bumped lightly from behind and the motor sounds like you cut the fuel real quick and let it back on,also it will rev up on its own and spit black smoke out it only has done this once going dow the road but frequently does it when first started. i also read about it could be the injectors not holding vacum and fuel running back to the tank and a way to tell is to take the fuel cap off and listen for suction. or it could be lift pump.,or oiloil getting past the turbo shaft. well i feel like im talking in circles hope its not to confuseing and ive been clear enough its hard to explain seeing that none of this happens exspecdly its alawys random any insite would be a great help, thanx
Offline  
Quick reply to this message
Sponsored Links
Advertisement
 
Old 10-05-2009, 11:55 PM   #2 (permalink)
wordtoyourmom
Diesel Specialist
 
wordtoyourmom's Avatar
 
Join Date: Sep 2009
Location: Abbotsford, BC
Posts: 582
iTrader Score: 0 reviews

I'd just start with the CDR...
__________________
1997 GMC Sierra SLE 2500 4x4 ext. cab long box, auto, 3.73's, 6.5 turbo, "F" VIN

Home made manual wastegate controller, 3" straight pipe exiting before the rear wheel, boost and EGT gauges, cranked T-bars and 2" blocks with 285/75's
Offline   Quick reply to this message
Old 10-06-2009, 10:42 AM   #3 (permalink)
Bison
Diesel Master
 
Bison's Avatar
 
Join Date: Apr 2007
Location: Close to Peace river,Alberta
Posts: 2,967
iTrader Score: 1 reviews

I would start by changing the crossover.
2) check that CDR for being open.
3)check for air in the fuel system and check fuel pressure.
__________________
98 GMC 2500 hd sle 6.5td ext cab l box 4x4 auto 4.10 difs 268000 km. HOME REBUILD ENGINE at 268.000 km,currently 307.000
Removed CDR an installed PROVENT CRANK CASE OIL SEPERATOR/VENTILATION VALVE,3 1/2" straight pipe.
PMD heatsink relocated to inside air stream in pass fender between batt and air filter.PMD is easely accessable.
Other mods, to nummerous to mention.
95 GMC SL 2500 6.5td ext cab sh box auto, 409.000 km,CDR vented to atmosfeer at 307 k, remote pmd, extra glow bypass/LP test switch, relocated OPS ,in cab fuel gauge .High idle switch,new paint.Foot dimmer swich for simultaniously high/low beam. The Wife's pride and joy.
89 GMC 2500 sle 4x4 ext cab 6.2 na stock 740000+ km, engine rebuilt at 660000 km, rusting out now, but runs like new.
Waldon Wheelloader repowered with 6.2 na.
3 tractors dsl ,72 AC 940 whj loader,ASV 4810 Positrack skidsteer
Offline   Quick reply to this message
Old 10-06-2009, 09:15 PM   #4 (permalink)
wallybly
Diesel Head
 
Join Date: Dec 2008
Posts: 41
iTrader Score: 0 reviews

what exactly does the cdr do? and what does the provent crank case oil seperater ventilation valve do,and how costly is it? how would i check for air in the fuel system, i thought that all you had to do was open the t valve on top of the motor until you get straight fuel with no air is that right? what should the fuel pressure be between 5&7?
how bad did it hurt it running it with the hole in the crossover pipe? i hope not bad i love this truck for some reason besides power i like driving it better than my duramax! id also like to know how you went about your high idle and foot dimmer? thanx
Offline   Quick reply to this message
Old 10-06-2009, 10:44 PM   #5 (permalink)
pmorrissette
Diesel Head
 
Join Date: Jun 2009
Location: Terrebonne, Qc., Canada (near Montreal)
Posts: 47
iTrader Score: 0 reviews

CDR = Crankcase Depression Regulator valve

Similar function to a PCV valve.

The Crankcase Depression Regulator (CDR) Valve maintains crankcase pressure. Pressure must be regulated to prevent oil consumption through the intake system, and to prevent oil leaks due to excessive buildup of pressure. Control is accomplished by regulating the blow-by gases into the intake system to be reburned. Inside the CDR valve, a spring holds open a valve plate that connects to the CDR valve body with a flexible diaphragm. The valve plate is capable of restricting the outlet passage to the turbocharger air inlet duct when airflow pulls it closed against the force of the spring.
__________________
VIN: 1GCHK33(F)2RJ358044
1994 Chevy Cheyenne K3500HD 4x4, 6.5TD, 4L80, remote PMD, new Delphi LP, new Delco OPS, DIY TurboMaster, patched up left rear fender!, new Delco CDR.
Offline   Quick reply to this message
Old 10-07-2009, 01:22 AM   #6 (permalink)
Bison
Diesel Master
 
Bison's Avatar
 
Join Date: Apr 2007
Location: Close to Peace river,Alberta
Posts: 2,967
iTrader Score: 1 reviews

Quote:
Originally Posted by wallybly View Post
what exactly does the cdr do? and what does the provent crank case oil seperater ventilation valve do,and how costly is it? how would i check for air in the fuel system, i thought that all you had to do was open the t valve on top of the motor until you get straight fuel with no air is that right? what should the fuel pressure be between 5&7?
how bad did it hurt it running it with the hole in the crossover pipe? i hope not bad i love this truck for some reason besides power i like driving it better than my duramax! id also like to know how you went about your high idle and foot dimmer? thanx
That POS called the CDR is supposed to keep the crank case under a slight vacuum and burn the crank case vapours in the engine.A novel idea,but less effective if you have a lot of blow by on a somewhat worn engine,this will cause excessive oil consumption ( a new CDR wont solve that problem)Or the thing is plugged shut. In the latter case to much crank case pressure will cause leaking seals and/or gaskets.

Running with a leaking crossover will make the turbo less effective cause that is driven by exhaust gas pressure,resulting in less power. it wont kill your engine though.

bleeding the fuel system is done by opening the bleed screw/plug on top of the filter and starting the LP till only fuel runs out.
The T-valve is primarily for water draining from the bottom of the filter,only bleeding there will leave the filter still full of air.You can use that T-valve drain hose to hook up a pressure gauge for checking pressure .min 5 psi at idle and at least 1 psi WOT.

high idle set up can be found in the stickies,PM me for the dimmer switch.

The provent does the same as the CDR,only it filters the oil out and puts it back where it belongs.
__________________
98 GMC 2500 hd sle 6.5td ext cab l box 4x4 auto 4.10 difs 268000 km. HOME REBUILD ENGINE at 268.000 km,currently 307.000
Removed CDR an installed PROVENT CRANK CASE OIL SEPERATOR/VENTILATION VALVE,3 1/2" straight pipe.
PMD heatsink relocated to inside air stream in pass fender between batt and air filter.PMD is easely accessable.
Other mods, to nummerous to mention.
95 GMC SL 2500 6.5td ext cab sh box auto, 409.000 km,CDR vented to atmosfeer at 307 k, remote pmd, extra glow bypass/LP test switch, relocated OPS ,in cab fuel gauge .High idle switch,new paint.Foot dimmer swich for simultaniously high/low beam. The Wife's pride and joy.
89 GMC 2500 sle 4x4 ext cab 6.2 na stock 740000+ km, engine rebuilt at 660000 km, rusting out now, but runs like new.
Waldon Wheelloader repowered with 6.2 na.
3 tractors dsl ,72 AC 940 whj loader,ASV 4810 Positrack skidsteer
Offline   Quick reply to this message
Old 10-07-2009, 01:26 AM   #7 (permalink)
94C1500
Diesel Master
 
94C1500's Avatar
 
Join Date: Mar 2009
Posts: 2,690
iTrader Score: 1 reviews

A little bit of blowby is not a problem. Fuel gets past the piston seals and is common, happens on anything, especially with 21:1 compression ratio.

If it were caused by the CDR it would be because its stuck closed, so if you can blow through it that aint causing you to see it now. If you used a lighter oil, or one with more detergent or something, who knows, just a little blowby could be a number of things. It might just be oil mist.
__________________
1994 C1500 - 4L80E & 3.42 rear; Custom Multi-Program Chip; L65 intake; "FTB", Walbro FRC-10 lift pump, pre-LP fuel filter & OPS relay mod; D-Tech FSD on heatsink; Big Turbo, 4" to 5" exhaust exits before axle, Cone air filter; "marine" injectors. Propane fumigation and WMI.
ENGINE DESIGN CALCULATORS
LIST OF RECOMMENDED MNX & MODS
HX40 or HX35 V-Band Exhaust Elbows
Offline   Quick reply to this message
Old 10-07-2009, 10:02 PM   #8 (permalink)
wallybly
Diesel Head
 
Join Date: Dec 2008
Posts: 41
iTrader Score: 0 reviews

Thanks a lot guys I appreciate the information, it was really helpful. I just got my crossover pipe today. I gotta talk to my buddy about using his fuel pressure gauge, I'm thinking about changing the filter and starting from scratch now that I know the proper ay to bleed it. I cant believe how helpful you guys have been, I posted 3 threads on my Duramax and only got one reply. Do either one of you know how to block off the EGR? Does anyone know what the plugs on the drivers side valve covers go to? When I bought the truck two out of three were unplugged, when I plugged the other two in all it did was set of the check engine light.
I was wondering what the story was with blow by coming out the dipstick, I read on Heath Diesel if you have blow by coming out the oil filler tube its not a good idea to modify the worn engine. But seeing as though it only coming out the dipstick do you think it would hurt the engine to add injectors and a chip? Do you know how much power the chip gives at the wheels? I know from experience, buying for a Duramax, its easy to put numbers on the box but what it actually puts out is different. Who would you recomend going threw Heath, Kennedy, or SS Diesel?
Thanks a lot for your help!!
Offline   Quick reply to this message
Old 10-07-2009, 11:32 PM   #9 (permalink)
94C1500
Diesel Master
 
94C1500's Avatar
 
Join Date: Mar 2009
Posts: 2,690
iTrader Score: 1 reviews

Heath, Kennedy, Westers, Engh Motors.

pull the CDR hose off and see blowby is coming out there, if not CDR is stuck closed. I have a good amount of vapor/mist, still runs awesome and hard.
__________________
1994 C1500 - 4L80E & 3.42 rear; Custom Multi-Program Chip; L65 intake; "FTB", Walbro FRC-10 lift pump, pre-LP fuel filter & OPS relay mod; D-Tech FSD on heatsink; Big Turbo, 4" to 5" exhaust exits before axle, Cone air filter; "marine" injectors. Propane fumigation and WMI.
ENGINE DESIGN CALCULATORS
LIST OF RECOMMENDED MNX & MODS
HX40 or HX35 V-Band Exhaust Elbows
Offline   Quick reply to this message
Old 10-08-2009, 12:41 AM   #10 (permalink)
Bison
Diesel Master
 
Bison's Avatar
 
Join Date: Apr 2007
Location: Close to Peace river,Alberta
Posts: 2,967
iTrader Score: 1 reviews

a compression test will give an good indication of the condition of the rings and valves.
anything between 350 to 400 psi with no more than 20/25 psi spread between high and low across all 8 is OK.

My wife's 95 has over 350 k on it and starts and runs very good,but blowby was so bad that i vented the CDR to the world,that cut the oil burning to allmost zero.Been running like that for 40 K
__________________
98 GMC 2500 hd sle 6.5td ext cab l box 4x4 auto 4.10 difs 268000 km. HOME REBUILD ENGINE at 268.000 km,currently 307.000
Removed CDR an installed PROVENT CRANK CASE OIL SEPERATOR/VENTILATION VALVE,3 1/2" straight pipe.
PMD heatsink relocated to inside air stream in pass fender between batt and air filter.PMD is easely accessable.
Other mods, to nummerous to mention.
95 GMC SL 2500 6.5td ext cab sh box auto, 409.000 km,CDR vented to atmosfeer at 307 k, remote pmd, extra glow bypass/LP test switch, relocated OPS ,in cab fuel gauge .High idle switch,new paint.Foot dimmer swich for simultaniously high/low beam. The Wife's pride and joy.
89 GMC 2500 sle 4x4 ext cab 6.2 na stock 740000+ km, engine rebuilt at 660000 km, rusting out now, but runs like new.
Waldon Wheelloader repowered with 6.2 na.
3 tractors dsl ,72 AC 940 whj loader,ASV 4810 Positrack skidsteer
Offline   Quick reply to this message
Sponsored Links
Advertisement
 
Sponsored Links
Advertisement
 
Closed Thread

Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
BFG - Blow Out ikoolu Wheels & Tires 5 07-30-2010 01:55 PM
What I blow?? captkirk Electrical 3 03-02-2009 11:20 PM
Blow by vsandmnv 6.2L Diesel Engine 2 02-27-2009 08:45 AM
Blow by hoot_223 6.2L Diesel Engine 5 06-13-2006 03:32 PM
Blow-by 4x4_76 Any Other Vehicles 1 09-28-2005 12:38 AM


All times are GMT -4. The time now is 06:18 AM.


Shoutbox provided by vBShout v6.2.1 (Lite) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
© AutoGuide

SEO by vBSEO 3.6.0