Random Misfires - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


2000-2005 Discuss your 2000-2005 Bonneville SE, SLE, and SSEi Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 03-04-2013, 07:04 PM   #1
Member
Posts like a V-Tak
Thread Starter
 
SLE2005's Avatar
 
Join Date: Nov 2010
Location: Cleveland, Ohio
Posts: 39
Thanks: 0
Thanked 0 Times in 0 Posts
SLE2005 is on a distinguished road
Default Random Misfires

I have a 05 Bonneville SLE with a 3.8 and I just started getting the Service Engine Soon light, I check with my ODBII reader and it just tells me "Random Misfires" I have 83K mile on original plugs, but would a O2 Sensor cause this or a Cam Sensor? I can drive the car, but it has NO Power and smells as if the brake pads are burning, but they are not. If it is the O2 sensor, Im not sure which one it would be.

Thanks.
SLE2005 is offline   Reply With Quote
Old 03-04-2013, 08:43 PM   #2
Senior Administrator








Certified Car Nut
 
Mike's Avatar
 
Join Date: Jul 2003
Location: Horseheads, NY
Posts: 15,649
Thanked 1,001 Times in 777 Posts
Mike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond reputeMike has a reputation beyond repute
Default

Umm, just so you know, the 3800'* are know for engine fires because of oil leaking from the front valve cover, dripping down the 1,3,5 sparkplug wires and onto the hot exhaust. I wonder if the smell your smelling is the oil burning up your plug wires causing the misfire??
Mike is offline   Reply With Quote
Old 03-04-2013, 09:39 PM   #3
certified crazy person
Certified GM nut
 
eltatertoto's Avatar
 
Join Date: Sep 2010
Location: hobart indiana (1 hr from chicago)
Posts: 1,871
Thanked 64 Times in 52 Posts
eltatertoto is a jewel in the rougheltatertoto is a jewel in the rougheltatertoto is a jewel in the rougheltatertoto is a jewel in the rough
Default

could be coils, wires, plugs or the crank sensor among other things. id do the plugs wires and coils. just general maintenance stuff anyway.
eltatertoto is offline   Reply With Quote
Old 03-04-2013, 10:56 PM   #4
Member
Posts like a V-Tak
Thread Starter
 
SLE2005's Avatar
 
Join Date: Nov 2010
Location: Cleveland, Ohio
Posts: 39
Thanks: 0
Thanked 0 Times in 0 Posts
SLE2005 is on a distinguished road
Default Misfires

I replaced the Plugs with AC Delco Platnium with AC Delco Wires, and it is still misfiring. All the wires are dry, and do not have any oil on them, plus I use Mobil 1 Full Synthetic Oil, which has a higher burn factor. I suspect the Cam Sensor, which is throwing the timing off, but I never replaced one on the Series II, I replaced it on a Series I Supercharged, but never on this series II, what do I need to remove for the Cam Sensor, the Water pump?
SLE2005 is offline   Reply With Quote
Old 03-05-2013, 07:47 AM   #5
Senior Member
True Car Nut
 
jwfirebird's Avatar
 
Join Date: Dec 2009
Location: western,ny state
Posts: 9,616
Thanked 563 Times in 481 Posts
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

ive never had to replace a cam sensor. why do you think the timing is off? i would test the fuel pressure and sniff the vacuum line on the fpr for gas (if you smell it its bad) it could be coils, icm, low fuel pressure, bunch of other things
jwfirebird is offline   Reply With Quote
Old 03-05-2013, 09:35 AM   #6
Senior Member

True Car Nut
 
2kg4u's Avatar
 
Join Date: Sep 2006
Location: Windsor, Ontario / Detroit, Michigan
Posts: 4,804
Thanked 220 Times in 181 Posts
2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of2kg4u has much to be proud of
Default

Quote:
Originally Posted by SLE2005 View Post
I replaced the Plugs with AC Delco Platnium with AC Delco Wires, and it is still misfiring. All the wires are dry, and do not have any oil on them, plus I use Mobil 1 Full Synthetic Oil, which has a higher burn factor. I suspect the Cam Sensor, which is throwing the timing off, but I never replaced one on the Series II, I replaced it on a Series I Supercharged, but never on this series II, what do I need to remove for the Cam Sensor, the Water pump?

Stick to the more common failures before you get into the cam sensor. If you replaced wires and plugs, I would check fuel pressure next. Have you changed the fuel filter in recent history? If not, change it. If that doesn't clear things up have the fuel pressure tested to see if the fuel pump is failing.

The other possibility is a bad ignition coil. Sometimes misfires on two cylinders will read as random misfires. Here is a link to a write up on how to check the coils:

https://www.gmforum.com/trouble-shoo...-wires-278818/
2kg4u is offline   Reply With Quote
Old 03-05-2013, 01:03 PM   #7
Member
Posts like a V-Tak
Thread Starter
 
SLE2005's Avatar
 
Join Date: Nov 2010
Location: Cleveland, Ohio
Posts: 39
Thanks: 0
Thanked 0 Times in 0 Posts
SLE2005 is on a distinguished road
Default

The problem was with the Ignition Control Module ICM. Thanks for all the advice
SLE2005 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Random misfires with code P0321 FaceShot 1992-1999 9 09-21-2009 09:23 AM
1998 Random cylinder misfires and code P0420 jllracer55 1992-1999 0 10-07-2008 12:41 PM
Help Please!! 03 SE pulled out code P-0300B random misfires. GM-Maine 2000-2005 8 03-18-2007 11:59 AM
Hmmm...KR @WOT w/93 Octane and misfires... Daron97SSE 1992-1999 6 03-13-2007 05:39 PM
P0300 Misfires past 4000 RPM impy 2000-2005 20 10-27-2006 10:00 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 03:43 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.