Inline 250, need some expert advice - The 1947 - Present Chevrolet & GMC Truck Message Board Network

c10hevy · 11-07-2011, 03:19 PM

I think the engine isn't running like it should. sounds like a pinging or possibly knocking? I'm not entirely sure, I'm new at diagnosing engine problems. Here's a video to give you guys an idea of what I'm working with.

http://youtu.be/cvko_jc01Zg

Some more great news, tightening the intake exhaust manifold bolts, the intake ears decided it was time to break up with the rest of the manifold.
Any ideas besides a whole new manifold?

Would this cause the engine to run like it is, obviously it I'snt going to help, but would it cause the sound and performance I'm experiencing?

I really appreciate all the help Ive found on here and my truck wouldn't be running at all without your guys help.

kieth · 11-07-2011, 03:41 PM

Sounded like the manifold was the problem all along,....get a new manifold and it should be just fine........Kieth

shawno72 · 11-07-2011, 03:58 PM

I agree sounded like an exhaust leak. My 292 has a wrist pin knock and it sounds nothing like that.

c10hevy · 11-07-2011, 04:02 PM

Man, I really hope you guys are right! I was worried the whole thing needed a rebuild. Does anyone have a line on a stock intake manifold? I cant seem to find any online by themselves.

Should I even worry about a stocker or just opt for an offy and 4 bbl?

I really appreciate the quick and knowledgeable responses!

shawno72 · 11-07-2011, 04:21 PM

Go with the offy if the motor can push it through.

c10hevy · 11-07-2011, 04:54 PM

What do you mean if the motor can push it? Does mine sound sick or dying? Besides the large hole in the side of the intake haha
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**pdxhall** · 11-07-2011, 05:11 PM

Quote:

Originally Posted by c10hevy

Man, I really hope you guys are right! I was worried the whole thing needed a rebuild. Does anyone have a line on a stock intake manifold? I cant seem to find any online by themselves.

Should I even worry about a stocker or just opt for an offy and 4 bbl?

I really appreciate the quick and knowledgeable responses!

I have a stock intake for sale. It's in the parts for sale section.

powerdriver 1958 · 11-07-2011, 05:32 PM

I'm going to move this to engine & drivetrain , Lots of helpful gents there

68gmsee · 11-07-2011, 07:47 PM

Yeah, it definitely sounds exactly like mine did this morning.

I had the brake booster hose off (bad booster) and had placed a small piece of electrical tape to plug the hole on the fitting on the intake so I could time the engine. When I started the truck part of the tape got swallowed into the hole and engine sounded just like yours. I thought valve or lifter was gone.

83gmc4x4 · 11-07-2011, 11:22 PM

Had a 73 GMC with a 250 that ran like that. A few of the bolt holes were stripped on head. a few heli-coils and a new intake and exhaust gaskets fixed it right up.

geoff.clark · 11-07-2011, 11:51 PM

I dont have a manifold for you, but I do have a new gasket if you need it. Bought it for my 250, but never used it.

c10hevy · 11-08-2011, 01:43 AM

I opted for an offy 4 bbl and a 500 cfm edelbrock. Hopefully that'll fix it right up. I'll let you guys know
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jayman68 · 11-08-2011, 01:59 AM

There is also Clifford Performance. Everything needed for performance inline 6.

http://www.cliffordperformance.net/M...gory_Code=C250

1Bad62Pro/Street · 11-08-2011, 08:00 PM

What year is your truck bud?
Since you live a stones throw away.

http://67-72chevytrucks.com/vboard/s...38#post4183038

http://67-72chevytrucks.com/vboard/f...play.php?f=117

c10hevy · 11-09-2011, 12:20 AM

It's a 66 gmc small back window step side short bed, currently my daily driver with suspension, steering, and brakes from a '91 sub
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c10hevy · 11-12-2011, 03:11 PM

I got the offy and the 500cfm Edelbrock in and running, I think it sounds much better! what do you guys think..?

http://youtu.be/UtI8wdi3qP8

sean1969c10 · 11-13-2011, 10:13 AM

Sounds good to me!
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c10hevy · 11-15-2011, 11:58 AM

So I've got it running, but the idle is real rough, it shakes the whole truck at the light. According to santucci's book, with an Hei you should gap the plugs between.05 and .08. Mine are at .065, could that be the problem?
It runs great when moving its just the idle that's crap. Any help would be great to keepmy daily driver daily.
Posted via Mobile Device

68gmsee · 11-15-2011, 02:03 PM

Quote:

Originally Posted by c10hevy

So I've got it running, but the idle is real rough, it shakes the whole truck at the light. According to santucci's book, with an Hei you should gap the plugs between.05 and .08. Mine are at .065, could that be the problem?
It runs great when moving its just the idle that's crap. Any help would be great to keepmy daily driver daily.
Posted via Mobile Device

I gapped mine to .045 in my 250 and it runs good.

c10hevy · 11-24-2011, 05:53 PM

I still cant figure out my idle. I took a video, but lost it. At idle it will knock a little bit and then increase idle a little and the knock goes away then it decreases rpm and knocks again. This goes on and on... any ideas?

everything is mechanical, manual choke etc...

c10hevy · 11-24-2011, 08:44 PM

After looking through a couple jeep 4.0 forums that have the exact same problem. Knocking at idle then fine after acceleration, and they were saying it was flexplate or torque converter. Does that have any relevance to my 250?

Thanks for all your guys input and advice!

c10hevy · 11-26-2011, 12:31 PM

any ideas?

11-07-2011, 03:19 PM	#1
c10hevy Registered User Join Date: Mar 2008 Location: Sandpoint ID Posts: 112	Inline 250, need some expert advice I think the engine isn't running like it should. sounds like a pinging or possibly knocking? I'm not entirely sure, I'm new at diagnosing engine problems. Here's a video to give you guys an idea of what I'm working with. http://youtu.be/cvko_jc01Zg Some more great news, tightening the intake exhaust manifold bolts, the intake ears decided it was time to break up with the rest of the manifold. Any ideas besides a whole new manifold? Would this cause the engine to run like it is, obviously it I'snt going to help, but would it cause the sound and performance I'm experiencing? I really appreciate all the help Ive found on here and my truck wouldn't be running at all without your guys help. Attached Images

11-07-2011, 03:41 PM	#2
kieth Registered User Join Date: Sep 2010 Location: Tulsa, Oklahoma Posts: 1,925	Re: Inline 250, need some expert advice Sounded like the manifold was the problem all along,....get a new manifold and it should be just fine........Kieth

11-07-2011, 03:58 PM	#3
shawno72 C/10 junkie Join Date: Nov 2010 Location: Stockton Ca Posts: 9,093	Re: Inline 250, need some expert advice I agree sounded like an exhaust leak. My 292 has a wrist pin knock and it sounds nothing like that. __________________ Shawn 70 LWB C10 current driver/project http://67-72chevytrucks.com/vboard/s...d.php?t=663051 68 SWB C10 Work in progress.....SOLD http://67-72chevytrucks.com/vboard/s...d.php?t=559520 72 LWB C10 Sold 71 LWB C10 Sold 68 LWB C10 CST Sold http://youtu.be/kbB0QrBIs9k My mom always had the best advice. It was just a tad late. After a fall that involved blood, she'd say....."Careful!"

11-07-2011, 04:02 PM	#4
c10hevy Registered User Join Date: Mar 2008 Location: Sandpoint ID Posts: 112	Re: Inline 250, need some expert advice Man, I really hope you guys are right! I was worried the whole thing needed a rebuild. Does anyone have a line on a stock intake manifold? I cant seem to find any online by themselves. Should I even worry about a stocker or just opt for an offy and 4 bbl? I really appreciate the quick and knowledgeable responses!

11-07-2011, 04:21 PM	#5
shawno72 C/10 junkie Join Date: Nov 2010 Location: Stockton Ca Posts: 9,093	Re: Inline 250, need some expert advice Go with the offy if the motor can push it through. __________________ Shawn 70 LWB C10 current driver/project http://67-72chevytrucks.com/vboard/s...d.php?t=663051 68 SWB C10 Work in progress.....SOLD http://67-72chevytrucks.com/vboard/s...d.php?t=559520 72 LWB C10 Sold 71 LWB C10 Sold 68 LWB C10 CST Sold http://youtu.be/kbB0QrBIs9k My mom always had the best advice. It was just a tad late. After a fall that involved blood, she'd say....."Careful!"

11-07-2011, 04:54 PM	#6
c10hevy Registered User Join Date: Mar 2008 Location: Sandpoint ID Posts: 112	Re: Inline 250, need some expert advice What do you mean if the motor can push it? Does mine sound sick or dying? Besides the large hole in the side of the intake haha Posted via Mobile Device

11-07-2011, 05:32 PM	#8
powerdriver 1958 Kid's Mechanic Join Date: Nov 2006 Location: Kansas City Posts: 8,241	Re: Inline 250, need some expert advice I'm going to move this to engine & drivetrain , Lots of helpful gents there

11-07-2011, 07:47 PM	#9
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: Inline 250, need some expert advice Yeah, it definitely sounds exactly like mine did this morning. I had the brake booster hose off (bad booster) and had placed a small piece of electrical tape to plug the hole on the fitting on the intake so I could time the engine. When I started the truck part of the tape got swallowed into the hole and engine sounded just like yours. I thought valve or lifter was gone.

11-07-2011, 11:22 PM	#10
83gmc4x4 Registered User Join Date: Jun 2010 Location: Parsons, KS Posts: 36	Re: Inline 250, need some expert advice Had a 73 GMC with a 250 that ran like that. A few of the bolt holes were stripped on head. a few heli-coils and a new intake and exhaust gaskets fixed it right up.

11-07-2011, 11:51 PM	#11
geoff.clark SheetMetalNoob Join Date: Jan 2010 Location: Fort Mill, SC Posts: 126	Re: Inline 250, need some expert advice I dont have a manifold for you, but I do have a new gasket if you need it. Bought it for my 250, but never used it. __________________ Geoff Clark Classic Truck NoOb 83 Chevy Custom Deluxe I6 250 lwb (aka) Trash Runner

11-08-2011, 01:43 AM	#12
c10hevy Registered User Join Date: Mar 2008 Location: Sandpoint ID Posts: 112	Re: Inline 250, need some expert advice I opted for an offy 4 bbl and a 500 cfm edelbrock. Hopefully that'll fix it right up. I'll let you guys know Posted via Mobile Device

11-08-2011, 01:59 AM	#13
jayman68 Fun Stuff Join Date: Jan 2010 Location: Sedro Woolley, WA Posts: 400	Re: Inline 250, need some expert advice There is also Clifford Performance. Everything needed for performance inline 6. http://www.cliffordperformance.net/M...gory_Code=C250 __________________ Jay 68 C10(project) 88 Honda Accord(DD) 93 Chevy Astro EXT 2wd

11-08-2011, 08:00 PM	#14
1Bad62Pro/Street "Where were you in '62?" Join Date: Jul 2004 Location: Cleveland County, North Cackalacky Posts: 5,013	Re: Inline 250, need some expert advice What year is your truck bud? Since you live a stones throw away. http://67-72chevytrucks.com/vboard/s...38#post4183038 http://67-72chevytrucks.com/vboard/f...play.php?f=117 __________________ PROJECT: "FULL METAL YELLOW JACKET" 1962 Chevy C-10 Stepside Shortbed Nostalgia Pro/Street Pickup Truck PROJECT: "FULL METAL YELLOW JACKET Build Thread What Are You Workin' On? - 1Bad62ChevyPickup PROJECT: "TYRANNORAMBLER REX" 1969 AMC Rambler American Nostalgia Pro/Street Youtube Channel: Father Son Projects Youtube Channel: 2TIMOTHY2FITHTEEN "North and South Carolina Folks Click Here!" (((( ~ I have Parts For Sale & Miscellaneous Stuff ~ )))) "Well being as there's no other place around the place, I reckon this must be the place, I reckon...Nyuk Nyuk Nyuk" -Curly Howard Ph.D.

11-09-2011, 12:20 AM	#15
c10hevy Registered User Join Date: Mar 2008 Location: Sandpoint ID Posts: 112	Re: Inline 250, need some expert advice It's a 66 gmc small back window step side short bed, currently my daily driver with suspension, steering, and brakes from a '91 sub Posted via Mobile Device

11-12-2011, 03:11 PM	#16
c10hevy Registered User Join Date: Mar 2008 Location: Sandpoint ID Posts: 112	Re: Inline 250, need some expert advice I got the offy and the 500cfm Edelbrock in and running, I think it sounds much better! what do you guys think..? http://youtu.be/UtI8wdi3qP8



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11-13-2011, 10:13 AM	#17
sean1969c10 Registered User Join Date: Mar 2008 Location: Powhatan, Va. Posts: 376	Re: Inline 250, need some expert advice Sounds good to me! Posted via Mobile Device __________________ Sean "If your gonna be dumb, you gotta be tough" 1960 Chevy Impala Sedan - my 25 year search is over!! 1969 C-10 longbed - Nice day DD 1970 Chevy Nova - Street and Strip Project 2002 Acura MDX my DD 2007 Honda Odssey - My Wife's "Mommy Van"

11-15-2011, 11:58 AM	#18
c10hevy Registered User Join Date: Mar 2008 Location: Sandpoint ID Posts: 112	Re: Inline 250, need some expert advice So I've got it running, but the idle is real rough, it shakes the whole truck at the light. According to santucci's book, with an Hei you should gap the plugs between.05 and .08. Mine are at .065, could that be the problem? It runs great when moving its just the idle that's crap. Any help would be great to keepmy daily driver daily. Posted via Mobile Device

11-24-2011, 05:53 PM	#20
c10hevy Registered User Join Date: Mar 2008 Location: Sandpoint ID Posts: 112	Re: Inline 250, need some expert advice I still cant figure out my idle. I took a video, but lost it. At idle it will knock a little bit and then increase idle a little and the knock goes away then it decreases rpm and knocks again. This goes on and on... any ideas? everything is mechanical, manual choke etc...

11-24-2011, 08:44 PM	#21
c10hevy Registered User Join Date: Mar 2008 Location: Sandpoint ID Posts: 112	Re: Inline 250, need some expert advice After looking through a couple jeep 4.0 forums that have the exact same problem. Knocking at idle then fine after acceleration, and they were saying it was flexplate or torque converter. Does that have any relevance to my 250? Thanks for all your guys input and advice!

11-26-2011, 12:31 PM	#22
c10hevy Registered User Join Date: Mar 2008 Location: Sandpoint ID Posts: 112	Re: Inline 250, need some expert advice any ideas?

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