It is currently Fri Mar 29, 2024 2:17 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 8 posts ] 
Author Message
PostPosted: Fri Apr 18, 2014 7:37 pm 
Offline
SE Member
SE Member
User avatar

Joined: Sun Nov 14, 2010 3:29 pm
Posts: 21
Year and Trim: 2002 SLE
It fine at idle but when you drive and accelerate especially after 20-30mph she starts to shudder and any faster than that and you hit the gas good it shudders real hard. But stops as soon as you let off the gas. First thing in morning no noticeable, but after a few minutes of driving it starts and the hotter the motor the harder the shudder. I changed my wires a few weeks ago have had my front end looked at by two diff garages and I just swapped coil pack and tested, they all sparked. Can anyone please help me figure this out??


Top
 Profile  
 
PostPosted: Fri Apr 18, 2014 7:38 pm 
Offline
SE Member
SE Member
User avatar

Joined: Sun Nov 14, 2010 3:29 pm
Posts: 21
Year and Trim: 2002 SLE
Oh and I have the evap code p0446 and p0300, it doesn't sputter like a bad plug normally would


Top
 Profile  
 
PostPosted: Fri Apr 18, 2014 11:18 pm 
Offline
Resident Gearhead
Resident Gearhead
User avatar

Joined: Mon May 19, 2008 10:30 pm
Posts: 8781
Location: Grand Rapids, Michigan
Year and Trim: 2014 Cadillac XTS Vsport.
Sounds like a plugged cat.

_________________
*Gone, but not forgotten* - Black 2000 SSEi, HIR Headlights, Angel Eyes fogs, 3rd brake light overlay, hi-flo cat, 180 degree thermostat, HS 1.9 rockers, LSx yellow springs, Intense FWI, PCM, shift kit, push rods, and 3.4 Pulley. ZZP Power Log.


Top
 Profile  
 
PostPosted: Sat Apr 19, 2014 8:15 am 
Offline
SLE Member
SLE Member

Joined: Sat Apr 19, 2014 8:02 am
Posts: 87
Year and Trim: 2004 Bonneville SE
Hi Everyone... New to the Group.

I had the EXACT same problem. And it turned out to be a Bad ICM. The ICM sits on a heatsink with thermal grease on it. Pretty much like a CPU in a PC.
My Bonne was throwing P0300 in Torque with a flashing CEL ( if you don't have Torque on your Droid Phone and an ELM327 bluetooth adapter.. you need to get on the train ASAP... its great) .

I had already changed the CAT, both 02 sensors, New MAP and MAF , Crankshaft Position sensor, New Plugs and wires and new coils.... not fixed

Took out the old ICM... wasnt a spec of thermal grease on it...cleaned the heatsink with Alcohol. Coated the new ICM with high end CPU thermal grease. Installed. Car is now running like new money.

I used to be under the impression that a BAD ICM's only symptom is a no-start. But some ICMs will cause misfires when HOT and eventually misfire even when COLD. However the car may still start fine.

Seen a guy an on an IMPALA group with the same exact problem and a new ICM fixed his as well on that 3800 S2 engine.


Top
 Profile  
 
PostPosted: Sun Apr 20, 2014 11:42 pm 
Offline
SE Member
SE Member
User avatar

Joined: Sun Nov 14, 2010 3:29 pm
Posts: 21
Year and Trim: 2002 SLE
I just had the cat changed two weeks ago


Top
 Profile  
 
PostPosted: Sun Apr 20, 2014 11:46 pm 
Offline
SE Member
SE Member
User avatar

Joined: Sun Nov 14, 2010 3:29 pm
Posts: 21
Year and Trim: 2002 SLE
Ok I will look into that tomorrow. But for some reason it stopped throwing the p0300 code and is now only saying p0446 evap thing not sure if that makes a difference but still will look. Do u have a diagram of where it is?


Top
 Profile  
 
PostPosted: Tue Apr 22, 2014 12:18 pm 
Offline
SLE Member
SLE Member

Joined: Sat Apr 19, 2014 8:02 am
Posts: 87
Year and Trim: 2004 Bonneville SE
bad fuel filter will make the 3800 S2 engine run like it has one cylinder... has that been changed?


Top
 Profile  
 
PostPosted: Sun Apr 27, 2014 8:49 pm 
Offline
SE Member
SE Member
User avatar

Joined: Sun Nov 14, 2010 3:29 pm
Posts: 21
Year and Trim: 2002 SLE
Bought one today will change it when it stops raining, also hanged my plugs today as well


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 

All times are UTC - 5 hours [ DST ]


Related topics
 Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. "shuddering" on acceleration - SOLVED

Oldman

15

2045

Mon Jul 06, 2015 3:11 pm

MKMike View the latest post

There are no new unread posts for this topic. Car bucks on hard acceleration

rongor

6

1583

Sun Mar 16, 2014 5:58 pm

J Wikoff View the latest post

There are no new unread posts for this topic. Flashing SES Light under hard Acceleration

[ Go to pageGo to page: 1, 2 ]

loudog1972

25

4107

Thu Jan 05, 2012 11:19 am

loudog1972 View the latest post

There are no new unread posts for this topic. Shuddering/shaking issue

jtmontano

1

897

Sun Aug 02, 2015 11:22 pm

1oldman View the latest post

There are no new unread posts for this topic. 2005 bonneville sometimes shifts hard

jcweis1

9

1747

Fri Jun 20, 2014 11:59 am

walnut777 View the latest post

 


Who is online

Users browsing this forum: Google [Bot] and 10 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group


phpBB SEO