Vibraton - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Kmart2352 · 04-09-2009, 04:21 PM

I've got a 87 Sierra Classic and i have a huge vibration in the motor. It is a 350 fuel enject. It has the vibration when it is about 2-3 thousand rpms and when i accelerate. Not sure what the problem could be. If you have any info on what it would be can really help me out.

Thanks

killerpickup · 04-09-2009, 04:50 PM

Boy: youve opened a real hornets nest here. 1. it could be anything from a fuel injecter thats dirty to a mismatched piston, also valve train problems, bad plug or wire, you have to check each out, one at a time.

Kmart2352 · 04-09-2009, 05:06 PM

The engine runs fine and I just did a whole tune up on the truck and i cleaned out the throttle body. I thought the vibration was the trans mount because the rubber was totally gone on that mount.

J_PEPIN87 · 04-09-2009, 05:13 PM

Maybe a harmonic balancer

Kmart2352 · 04-09-2009, 05:36 PM

I was thinking of that or the motor mounts

Adams74Chevy · 04-09-2009, 05:53 PM

Quote:

Originally Posted by Kmart2352

The engine runs fine and I just did a whole tune up on the truck...

How long ago? When I had my S-10 I changed the plugs & wires but didn't realize till later that one plug wire didn't snap onto the plug the boot just held it in place...sometimes the simplest things are the biggest problems, plus it's a free and quick check. YMMV

billnorman · 04-09-2009, 07:44 PM

Has anybody had the flywheel off lately? I believe 350's and 4.3's require an internally balanced (engine) flexplate, and other blocks use an externally balanced flexplate/flywheel. However, the wrong flywheels will bolt up.

Kmart2352 · 04-09-2009, 09:53 PM

I did it last year in the middle of the summer.Then this year i went and checked it all.

85Bowtie · 04-10-2009, 07:50 AM

Does it do it while your driving or while it's in park and you rev it up?

Kmart2352 · 04-10-2009, 08:50 AM

yes, when i rev it up it still vibrates.

bigarmzz · 04-10-2009, 12:02 PM

Quote:

Originally Posted by Kmart2352

I've got a 87 Sierra Classic and i have a huge vibration in the motor. It is a 350 fuel enject. It has the vibration when it is about 2-3 thousand rpms and when i accelerate. Not sure what the problem could be. If you have any info on what it would be can really help me out.

Thanks

since you've already done a full tune up, i'd def check the motor mounts bud

f.monroe · 04-12-2009, 03:37 PM

Remove all of the drive belts from the engine and crank it . See if it still does it . If not , it iis in the accessories on the front of the engine . I have seen a bent fan blade cause this and this is how I found it .
Frank

Kmart2352 · 04-12-2009, 04:46 PM

Thanks Frank i will check that on my next free day.

Kmart2352 · 04-17-2009, 10:22 PM

Thanks for all of the input guys. I figure out is something electrical or something not going right in side the motor but prolly something elctrical. It gets better every time i replace or fix something. Thanks again.

04-09-2009, 04:21 PM	#1
Kmart2352 Registered User Join Date: Apr 2009 Location: Saco, Maine Posts: 151	Vibraton I've got a 87 Sierra Classic and i have a huge vibration in the motor. It is a 350 fuel enject. It has the vibration when it is about 2-3 thousand rpms and when i accelerate. Not sure what the problem could be. If you have any info on what it would be can really help me out. Thanks

04-09-2009, 04:50 PM	#2
killerpickup Registered User Join Date: Aug 2008 Location: Seabeck WA. Posts: 20	Re: Vibraton Boy: youve opened a real hornets nest here. 1. it could be anything from a fuel injecter thats dirty to a mismatched piston, also valve train problems, bad plug or wire, you have to check each out, one at a time.

04-09-2009, 05:06 PM	#3
Kmart2352 Registered User Join Date: Apr 2009 Location: Saco, Maine Posts: 151	Re: Vibraton The engine runs fine and I just did a whole tune up on the truck and i cleaned out the throttle body. I thought the vibration was the trans mount because the rubber was totally gone on that mount.

04-09-2009, 05:13 PM	#4
J_PEPIN87 Registered User Join Date: Sep 2008 Location: PASADENA,TX Posts: 206	Re: Vibraton Maybe a harmonic balancer

04-09-2009, 05:36 PM	#5
Kmart2352 Registered User Join Date: Apr 2009 Location: Saco, Maine Posts: 151	Re: Vibraton I was thinking of that or the motor mounts

04-09-2009, 07:44 PM	#7
billnorman Registered User Join Date: Mar 2009 Location: glen burnie md Posts: 174	Re: Vibraton Has anybody had the flywheel off lately? I believe 350's and 4.3's require an internally balanced (engine) flexplate, and other blocks use an externally balanced flexplate/flywheel. However, the wrong flywheels will bolt up.

04-09-2009, 09:53 PM	#8
Kmart2352 Registered User Join Date: Apr 2009 Location: Saco, Maine Posts: 151	Re: Vibraton I did it last year in the middle of the summer.Then this year i went and checked it all.

04-10-2009, 07:50 AM	#9
85Bowtie Registered User Join Date: Mar 2009 Location: TN Posts: 410	Re: Vibraton Does it do it while your driving or while it's in park and you rev it up? __________________ '69 Dodge Charger R/T 440, 727, 3.55 Sure Grip '68 Plymouth Road Runner 383, 727, 3.23 Sure Grip '89 Dodge Diplomat ex cop car 408, 727, 3.55 Sure Grip '77 Dodge Monaco ex cop car 440, 727, 2.71 '79 Dodge 'Lil Red Express pickup 360, 727, 3.55 Sure Grip '12 Dodge Challenger SRT8 392, M6, 3.92 '85 Chevrolet C-10 SWB 2wd 305, TH350, 2.73

04-10-2009, 08:50 AM	#10
Kmart2352 Registered User Join Date: Apr 2009 Location: Saco, Maine Posts: 151	Re: Vibraton yes, when i rev it up it still vibrates.

04-12-2009, 03:37 PM	#12
f.monroe Senior Member Join Date: May 2004 Location: Caldwell,Tx. Posts: 3,648	Re: Vibraton Remove all of the drive belts from the engine and crank it . See if it still does it . If not , it iis in the accessories on the front of the engine . I have seen a bent fan blade cause this and this is how I found it . Frank __________________ Born and proudly residing in a Red State !

04-12-2009, 04:46 PM	#13
Kmart2352 Registered User Join Date: Apr 2009 Location: Saco, Maine Posts: 151	Re: Vibraton Thanks Frank i will check that on my next free day.

04-17-2009, 10:22 PM	#14
Kmart2352 Registered User Join Date: Apr 2009 Location: Saco, Maine Posts: 151	Re: Vibraton Thanks for all of the input guys. I figure out is something electrical or something not going right in side the motor but prolly something elctrical. It gets better every time i replace or fix something. Thanks again. __________________ 87 2wd GMC Sierra Classic. 86 4wd GMC Sierra Classic. 95 2wd GMC Sierra. 96 2wd Chevrolet S-10.

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