« previous next »
Pages: [1] 2   Go Down

Author Topic: engine vibration  (Read 6871 times)

Offline Low87

  • Newbie
  • Posts: 91
engine vibration
« on: May 25, 2011, 08:22:45 am »
The 89 Jimmy has some vibration in the steering wheel at idle.  If you pop the hood with the engine running you can see the engine moving side to side more than it should.  I'm hoping it's just engine mounts, but is there anything else I should look at?
Logged

Offline PromiseKeeper

  • Frequent Member
  • **
  • Posts: 438
Re: engine vibration
« Reply #1 on: May 25, 2011, 08:30:59 am »
Could it be that your idle is just set too low? See if it gets better by increasing the engine speed just a tad with the gas pedal while its idling and see if it smooths out.
Logged
1980 C-10 2WD short & wide. 305 auto.

Offline Low87

  • Newbie
  • Posts: 91
Re: engine vibration
« Reply #2 on: May 25, 2011, 01:42:50 pm »
That seems to help for the most part.  How do I adjust idle on a TBI engine?
Logged

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19171
Re: engine vibration
« Reply #3 on: May 25, 2011, 08:44:40 pm »
Don't.

Unplug the vacuum hose at the egr valve and see if it idles better.
Logged
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline the_legend_1981

  • Frequent Member
  • **
  • Posts: 288
Re: engine vibration
« Reply #4 on: May 25, 2011, 10:04:05 pm »
what if it does? leave it unplugged?
Logged

Offline 1979C20

  • Senior Member
  • ****
  • Posts: 1659
  • Kyle Taulton.
Re: engine vibration
« Reply #5 on: May 26, 2011, 12:26:39 am »
Quote from: the_legend_1981 on May 25, 2011, 10:04:05 pm
what if it does? leave it unplugged?
If it does than than the EGR is bad and either needs replaced or removed.
Logged
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline Blazin

  • Blazin new trails!
  • Senior Member
  • ****
  • Posts: 6130
Re: engine vibration
« Reply #6 on: May 26, 2011, 05:46:47 am »
Probably not the case here but bought a truck with a 350 one time that did this. Turns out some dub had put a 400 flex plate on it!
Logged
Some people are like Slinkies. Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs

Offline Low87

  • Newbie
  • Posts: 91
Re: engine vibration
« Reply #7 on: May 26, 2011, 08:15:26 am »
Thanks Vile, I'll check that tonight.  Acceleration & driving is smooth, so hopefully it's something simple.
Logged

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19171
Re: engine vibration
« Reply #8 on: May 26, 2011, 01:10:18 pm »
Quote from: 1979C20 on May 26, 2011, 12:26:39 am
Quote from: the_legend_1981 on May 25, 2011, 10:04:05 pm
what if it does? leave it unplugged?
If it does than than the EGR is bad and either needs replaced or removed.

No, if it does that means the EGR solenoid is sticking allowing vacuum to the EGR valve at idle. Very common problem.
Logged
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline 1979C20

  • Senior Member
  • ****
  • Posts: 1659
  • Kyle Taulton.
Re: engine vibration
« Reply #9 on: May 26, 2011, 03:02:53 pm »
Quote from: VileZambonie on May 26, 2011, 01:10:18 pm
Quote from: 1979C20 on May 26, 2011, 12:26:39 am
Quote from: the_legend_1981 on May 25, 2011, 10:04:05 pm
what if it does? leave it unplugged?
If it does than than the EGR is bad and either needs replaced or removed.

No, if it does that means the EGR solenoid is sticking allowing vacuum to the EGR valve at idle. Very common problem.
Or, in laymens terms "bad".
Logged
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline PromiseKeeper

  • Frequent Member
  • **
  • Posts: 438
Re: engine vibration
« Reply #10 on: May 26, 2011, 09:12:05 pm »
Vile can correct me if I'm wrong on this. You should be able to take that vacuum line off of the EGR and suck on it enough to tell if the diaphragm in the EGR is working. I had one once that was stuck and when I did this it freed up and worked correctly again.
Logged
1980 C-10 2WD short & wide. 305 auto.

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19171
Re: engine vibration
« Reply #11 on: May 26, 2011, 11:09:58 pm »
Quote from: 1979C20 on May 26, 2011, 03:02:53 pm
Quote from: VileZambonie on May 26, 2011, 01:10:18 pm
Quote from: 1979C20 on May 26, 2011, 12:26:39 am
Quote from: the_legend_1981 on May 25, 2011, 10:04:05 pm
what if it does? leave it unplugged?
If it does than than the EGR is bad and either needs replaced or removed.

No, if it does that means the EGR solenoid is sticking allowing vacuum to the EGR valve at idle. Very common problem.
Or, in laymens terms "bad".

No, the EGR Solenoid would be "bad" not the EGR valve
Logged
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Low87

  • Newbie
  • Posts: 91
Re: engine vibration
« Reply #12 on: May 27, 2011, 08:20:55 am »
I took the line off the EGR valve last night and it didn't seem to make a difference.  When I went to put it back in place, I noticed there are two nipples coming off the back of it.  I plugged the line into the other one (I think) and the engine smoothed out. 
Logged

Offline 1979C20

  • Senior Member
  • ****
  • Posts: 1659
  • Kyle Taulton.
Re: engine vibration
« Reply #13 on: May 27, 2011, 03:40:39 pm »
When you unplug the hose to the egr, you have to plug the hose with a screw, bolt, thumb otherwise there will be a vacuum leak.
Logged
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF

Offline VileZambonie

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 19171
Re: engine vibration
« Reply #14 on: May 27, 2011, 09:09:38 pm »
No, there should be NO vacuum to the EGR valve. If you unplug the vaccum hose and there's vacuum present, there's your problem.
Logged
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10
Pages: [1] 2   Go Up
« previous next »