|
03-30-2013, 04:56 PM
|
#1 |
|
Senior Member
 
Join Date: Oct 2012
Location: mountain view arkansas
Posts: 1,316
|
350 vibration
I have a 84 Chevy 4x4 with a 350 auto. At idle it vibrates and when revved up you can feel it vibrate. I thought it was missing but you can put it in gear and give it gas and hold the brake and it does not miss. I replaced the plug wires and the plugs looked good. Could it be the harmonic balancer? I need it smooth because I am trying to sell the truck.
__________________
http://67-72chevytrucks.com/vboard/s...d.php?t=548705 |
|
|
|
03-31-2013, 09:11 AM
|
#2 |
|
Registered User
Join Date: Sep 2011
Location: Chesterfield, Va.
Posts: 339
|
Re: 350 vibration
Could be the H.B., but I'd check 1 more thing before I replaced it... Run a compression test across all the cylinders and make sure they are even. It could be all 8 are firing, but 1 cylinder is way weaker than the others. For example all are 120 and one is 80, or some stuff like that. A burnt valve can act like this.
|
|
|
|
03-31-2013, 08:44 PM
|
#3 |
|
78K & 79C Jimmys
Join Date: Nov 2009
Location: Ottawa Ont CANADA
Posts: 7,901
|
Re: 350 vibration
check for bent/cracked/broken fan blades
Posted via Mobile Device
__________________
John 1978 GMCJimmy4X4-350/203 1979 GMCJimmy4X2-305/350 |
|
|
|
|
03-31-2013, 08:53 PM
|
#4 |
|
Senior Member
Join Date: Oct 2012
Location: mountain view arkansas
Posts: 1,316
|
Re: 350 vibration
Thanks for the replies Compression was good. I slowed the timing down a little and it seemed to help at idle. The engine runs very well so it shouldn't be much.
__________________
http://67-72chevytrucks.com/vboard/s...d.php?t=548705 |
|
|
|
|
03-31-2013, 09:12 PM
|
#5 |
|
Registered User
Join Date: Sep 2010
Location: Marble Falls, TX
Posts: 1,575
|
Re: 350 vibration
Just tell 'em it has a mean cam in it
__________________
Michael Re-starting the neglected '77...http://67-72chevytrucks.com/vboard/s...=425464&page=9 |
|
|
|
 |
| Bookmarks |
|
|
Linear Mode
