Diesel question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**old Rusty C10** · 11-03-2012, 07:53 PM

My 6.2 has a problem that im hoping is an easy fix. Its a CUCV . I start it cold and for a while it runs with an exhaust valve that i think is stuck open as exhaust backs up through the intake and you see puffs of smoke coming out the air cleaner.During this it misses and doesnt want to rev up past 2000 RPM. Usually after it warms up this goes away and it runs good..
The truck has just over 30K on it
Is there something i can run through the motor in the oil or something that is a quick easy fix or am i looking at a major job rebuilding heads or the motor?

**hatzie** · 11-03-2012, 08:01 PM

Sticking Intake valve? Sticky EGR?

**old Rusty C10** · 11-03-2012, 08:47 PM

it makes a popping noise and you see a puff of smoke come out the intake on the left side so i was thinking it was something with a valve?

Phillip Pennartz · 11-03-2012, 09:44 PM

Don't egr s work after the engine gets warm?

ElGracho · 11-03-2012, 09:52 PM

J code 6.2s in cucvs dont have egr. Are you sure its exhaust?
Posted via Mobile Device

**old Rusty C10** · 11-03-2012, 10:05 PM

im not 100% sure i was thinking because i saw smoke coming out it was prolly exhaust ill see if i can video it tomorrow

86c20 · 11-03-2012, 11:55 PM

the only other thing i can think of would be late timing to cause white smoke but that is a really far shot. i would try some mistory oil just to losen things up and where it has been sitting a long time to may just be some gunk in there

**Corts60** · 11-04-2012, 12:54 AM

Hey Bob, if you own or can get ahold of a digital temp gun, shoot the exhaust at each cylinder while it is running and see which one is colder than the rest...that'll at least point you in the direction of where to start looking for issues.

**old Rusty C10** · 11-04-2012, 08:21 AM

Quote:

Originally Posted by Corts60

Hey Bob, if you own or can get ahold of a digital temp gun, shoot the exhaust at each cylinder while it is running and see which one is colder than the rest...that'll at least point you in the direction of where to start looking for issues.

That's an excellent idea i know someone with one for construction im gonna see if it will work for this thanks!!

GM72K10 · 11-04-2012, 12:12 PM

You may also have Sticking injector, run some diesel
Clean thru these trucks hAve been sitting sometimes for years
Posted via Mobile Device

**old Rusty C10** · 11-04-2012, 01:47 PM

Its funny because i was one step ahead of you on that one.. the first day i went and got batteries for the truck i picked up a 16 oz bottle of that and dumped half of it in the gas. The truck came with almost a full tank of gas and i was thinking the same thing.. I always throw Stabil in the gas motors so this thing I was told this is the best stuff for it so i said why not.. I got the Diesel Kleen plus octane boost by Power Service

ElGracho · 11-04-2012, 09:36 PM

First thing I would do is run it. It might just be wishful thinking, but the 6.2s I've gotten have all sat around a bit before I got hold of them. I've had 4 now and all of them got better and better the more I ran them.

What I meant by "are you sure it's exhaust" is that you often see some fuel/oil mist coming back into the intake when these 6.2s are running. I'm not sure of the dynamics but it's probably mostly the crankcase venting scheme they have and some blowby. With no vacuum, they don't use PCV systems but they have something similar. Each intake manifold on the 6.2s I have has been coated down pretty well with fuel and oil and there is an occasional fog / fuel oil mist rolling by.

Before people say all of my 6.2s were worn out junk, that may be true but after about 400k miles of running them, I'll take that junk any day...

11-03-2012, 07:53 PM	#1
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,310	Diesel question My 6.2 has a problem that im hoping is an easy fix. Its a CUCV . I start it cold and for a while it runs with an exhaust valve that i think is stuck open as exhaust backs up through the intake and you see puffs of smoke coming out the air cleaner.During this it misses and doesnt want to rev up past 2000 RPM. Usually after it warms up this goes away and it runs good.. The truck has just over 30K on it Is there something i can run through the motor in the oil or something that is a quick easy fix or am i looking at a major job rebuilding heads or the motor? __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

11-03-2012, 08:01 PM	#2
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,977	Re: Diesel question Sticking Intake valve? Sticky EGR? __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

11-03-2012, 08:47 PM	#3
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,310	Re: Diesel question it makes a popping noise and you see a puff of smoke come out the intake on the left side so i was thinking it was something with a valve? __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

11-03-2012, 09:44 PM	#4
Phillip Pennartz Registered User Join Date: Jun 2000 Location: Wichita Falls,Tx Posts: 56	Re: Diesel question Don't egr s work after the engine gets warm?

11-03-2012, 09:52 PM	#5
ElGracho Gentleman Jim Driver Join Date: Nov 2002 Location: Poulsbo, WA Posts: 1,553	Re: Diesel question J code 6.2s in cucvs dont have egr. Are you sure its exhaust? Posted via Mobile Device __________________ Joe '75 GMC Gentleman Jim '84 Chev C10 Short Wide - Super duper plain (manual steering, manual brakes, no dome light, no cig lighter) '85 Chev C10 Short Wide - Super plain Vortec 4.8 4L60E trans also: '81 K30, '83 C30 Crew Dually, '84 M1028 CUCV, '85 M1009 CUCV, another '85 C10 SWB, '89 R3500 Flatbed

11-03-2012, 10:05 PM	#6
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,310	Re: Diesel question im not 100% sure i was thinking because i saw smoke coming out it was prolly exhaust ill see if i can video it tomorrow __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

11-03-2012, 11:55 PM	#7
86c20 Registered User Join Date: Mar 2012 Location: edgartown mass Posts: 852	Re: Diesel question the only other thing i can think of would be late timing to cause white smoke but that is a really far shot. i would try some mistory oil just to losen things up and where it has been sitting a long time to may just be some gunk in there __________________ 1986 c20 "the hillbilly" 350 sm465 3.42gears 21mpg at 70mph 1985 k30 "the ice cream truck from hell" no rust az truck 197-8??? c30 "ramp truck" 454 1978 monte carlo 350 350th with 2.73 gears. no rust. sc car

11-04-2012, 12:54 AM	#8
Corts60 Just here to tinker Join Date: Jun 2008 Location: Holland, MI Posts: 3,697	Re: Diesel question Hey Bob, if you own or can get ahold of a digital temp gun, shoot the exhaust at each cylinder while it is running and see which one is colder than the rest...that'll at least point you in the direction of where to start looking for issues. __________________ 78 C10 SWB Diesel #1 (wrecked)http://67-72chevytrucks.com/vboard/s...1978+silverado 78 C10 SWB Diesel #2 (sold)http://67-72chevytrucks.com/vboard/s...d.php?t=650751 60 GMC Suburban (sold)http://67-72chevytrucks.com/vboard/s...d.php?t=445526 60 GMC 1000 (sold)http://67-72chevytrucks.com/vboard/showthread.php?t=298235 67 GMC 1500 (sold) http://67-72chevytrucks.com/vboard/s...d.php?t=803695 73 Chevy C20(Daily)http://67-72chevytrucks.com/vboard/s...d.php?t=852767 86 Suburban(summer unit) http://67-72chevytrucks.com/vboard/s...d.php?t=810697 88 Suburban 4x4(sold)

11-04-2012, 12:12 PM	#10
GM72K10 Next! Join Date: Jan 2003 Location: Eastern Pa. Posts: 2,483	Re: Diesel question You may also have Sticking injector, run some diesel Clean thru these trucks hAve been sitting sometimes for years Posted via Mobile Device __________________ 86 K30 CUCV M1028A1 86 K30 CUCV M1028a2 dually 86 K30 C&C 6.2 4:56s, 4M, 11,000 gvw, ex fire truck, now lowboy dump More square bodies and CUCVs than I care to admit to 2020 Silverado K3500HD Work truck

11-04-2012, 01:47 PM	#11
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,310	Re: Diesel question Its funny because i was one step ahead of you on that one.. the first day i went and got batteries for the truck i picked up a 16 oz bottle of that and dumped half of it in the gas. The truck came with almost a full tank of gas and i was thinking the same thing.. I always throw Stabil in the gas motors so this thing I was told this is the best stuff for it so i said why not.. I got the Diesel Kleen plus octane boost by Power Service __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

11-04-2012, 09:36 PM	#12
ElGracho Gentleman Jim Driver Join Date: Nov 2002 Location: Poulsbo, WA Posts: 1,553	Re: Diesel question First thing I would do is run it. It might just be wishful thinking, but the 6.2s I've gotten have all sat around a bit before I got hold of them. I've had 4 now and all of them got better and better the more I ran them. What I meant by "are you sure it's exhaust" is that you often see some fuel/oil mist coming back into the intake when these 6.2s are running. I'm not sure of the dynamics but it's probably mostly the crankcase venting scheme they have and some blowby. With no vacuum, they don't use PCV systems but they have something similar. Each intake manifold on the 6.2s I have has been coated down pretty well with fuel and oil and there is an occasional fog / fuel oil mist rolling by. Before people say all of my 6.2s were worn out junk, that may be true but after about 400k miles of running them, I'll take that junk any day... __________________ Joe '75 GMC Gentleman Jim '84 Chev C10 Short Wide - Super duper plain (manual steering, manual brakes, no dome light, no cig lighter) '85 Chev C10 Short Wide - Super plain Vortec 4.8 4L60E trans also: '81 K30, '83 C30 Crew Dually, '84 M1028 CUCV, '85 M1009 CUCV, another '85 C10 SWB, '89 R3500 Flatbed



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.