engine shakes on startup

If there isn't a place for your question then put it here.
User avatar
Berry
Registered User
Posts: 176
Joined: Sun Sep 02, 2012 11:29 am

engine shakes on startup

Postby Berry » Sun May 15, 2016 7:49 am

hi
I hadn't this issue before: when I start the engine, it shakes badly together with the rattling exhaust pipe. only on startup.
I'm sure it's mount-related. so when I put a jack with a block of wood under the oil pan there is no shaking.
but which could be the likely culprit? the motor mount, transmission mount or torque strut mount? or or?
any ideas?


...cruising
92 GT 3.1 MPFI auto 57K white

Image

User avatar
1988GTU
Registered User
Posts: 2744
Joined: Sat Mar 23, 2002 1:06 pm
Location: A town up north
Has thanked: 18 times
Been thanked: 11 times

Re: engine shakes on startup

Postby 1988GTU » Sun May 15, 2016 11:06 am

TSM with a shot in the dark guess with no visual identification of your vehicles actual parts in question. Also assuming no service engine soon illuminated, all ignition components working as they should, and exhaust hangers in tact.


_________
Image
-------------

User avatar
Berry
Registered User
Posts: 176
Joined: Sun Sep 02, 2012 11:29 am

Re: engine shakes on startup

Postby Berry » Sun May 15, 2016 5:53 pm

everything works as it should. except this: since yesterday there is a ticking noise coming from the back exhaust manifold. seems to be a exhaust leak.


...cruising
92 GT 3.1 MPFI auto 57K white

Image

User avatar
1988GTU
Registered User
Posts: 2744
Joined: Sat Mar 23, 2002 1:06 pm
Location: A town up north
Has thanked: 18 times
Been thanked: 11 times

Re: engine shakes on startup

Postby 1988GTU » Sun May 15, 2016 7:25 pm

make sure you dont have an ign wire arcing pre-plug back there.


_________
Image
-------------

User avatar
Berry
Registered User
Posts: 176
Joined: Sun Sep 02, 2012 11:29 am

Re: engine shakes on startup

Postby Berry » Mon May 16, 2016 7:41 am

thanks for the hint.
update: the engine shakes only along the horizontal axis parallel to the axle. i think it's a bad engine mount.

startup:
http://www.youtube.com/watch?v=q1dXzl5Wd1U

ticking noise:
http://www.youtube.com/watch?v=TsY6AUABEtY


...cruising
92 GT 3.1 MPFI auto 57K white

Image

User avatar
3X00-Modified
Administrator
Posts: 10657
Joined: Thu Jul 05, 2007 9:18 am
Location: Plainfield CT
Has thanked: 12 times
Been thanked: 46 times

Re: engine shakes on startup

Postby 3X00-Modified » Mon May 16, 2016 8:57 am

Thats pretty typical engine movement on startup, especially one with stock mounts that aren't changed for polyurethane... You may have a worn torque strut that is making it a bit more aggressive than normal so I'd start there if you still want to check. The ticking is probably a manifold leak at the pipe, OR at the head unfortunately. When manifold to head exhaust gaskets start leaking they almost sound like a bad lifter and it's just a small exhaust leak.



User avatar
Berry
Registered User
Posts: 176
Joined: Sun Sep 02, 2012 11:29 am

Re: engine shakes on startup

Postby Berry » Tue May 17, 2016 5:35 pm

thanks mr. pink!
hey guys, you know what? a part of the problem was my aftermarket starter motor (remy). it grinded up the flywheel a bit. too much clearance even without shim caused this shaking. i swapped the starter with a original one: the engine shakes less than before. not perfect, but much better. anyway i ordered a torque strut.


...cruising
92 GT 3.1 MPFI auto 57K white

Image

User avatar
Berry
Registered User
Posts: 176
Joined: Sun Sep 02, 2012 11:29 am

Re: engine shakes on startup

Postby Berry » Fri May 20, 2016 6:29 pm

oops! the exhaust leak turned out to be a loose spark plug on cyl #3


...cruising
92 GT 3.1 MPFI auto 57K white

Image

User avatar
3X00-Modified
Administrator
Posts: 10657
Joined: Thu Jul 05, 2007 9:18 am
Location: Plainfield CT
Has thanked: 12 times
Been thanked: 46 times

Re: engine shakes on startup

Postby 3X00-Modified » Fri May 20, 2016 7:48 pm

Good catch, and easy fix

Sent from my Nexus 5X using Tapatalk



User avatar
1988GTU
Registered User
Posts: 2744
Joined: Sat Mar 23, 2002 1:06 pm
Location: A town up north
Has thanked: 18 times
Been thanked: 11 times

Re: engine shakes on startup

Postby 1988GTU » Sat May 21, 2016 4:55 pm

Now ya have ignition components work as they should!


_________
Image
-------------

User avatar
Berry
Registered User
Posts: 176
Joined: Sun Sep 02, 2012 11:29 am

Re: engine shakes on startup

Postby Berry » Sat May 21, 2016 6:29 pm

true. you were right about the ignition components!


...cruising
92 GT 3.1 MPFI auto 57K white

Image

User avatar
1988GTU
Registered User
Posts: 2744
Joined: Sat Mar 23, 2002 1:06 pm
Location: A town up north
Has thanked: 18 times
Been thanked: 11 times

Re: engine shakes on startup

Postby 1988GTU » Sat May 21, 2016 9:00 pm

It's usually the first place I'd start* for those symptoms... *[snare drum and cymbal]


_________
Image
-------------


Return to “General Questions”

Who is online

Users browsing this forum: No registered users and 1 guest