1999 Cadillac Escalade 5.7 p0306 code - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Introductions for new members New to the Forum? Introduce yourself here. Been around awhile? Tell us about yourself. We at GMF Love to meet new Members! So pull up a chair and have a beverage.

Reply
 
 
 
Thread Tools Search this Thread
Old 04-12-2011, 10:53 AM   #1
Junior Member
Thread Starter
 
Join Date: Apr 2011
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
nmvettes is on a distinguished road
Default 1999 Cadillac Escalade 5.7 p0306 code

This problem has bugged me for several days already and still the check engine light stays on. The vehicle is a 1999 Cadillac Escalade 5.7 with code P0306. P0306 is a cylinder #6 misfire code. This is what I have done so far: New spark plugs, new plug wires, new cap and rotor, new fuel injector, new air and fuel filter. The compression test shows 150 psi which is very good still, especially for a vehicle with 185 k miles. I have cleaned the air mass sensor, the throttle body, and the connector points for all other sensors as well. Thinking that I may have installed faulty new plugs or wires, I then tested them and moved them around, no difference. Any suggestions anyone? Thanks
nmvettes is offline   Reply With Quote
Old 04-12-2011, 11:03 AM   #2
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

I think the 5.7 has individual ignition coils for each cylinder. Switch the ignition coil for cylinder 6 with another cylinder and see if the misfire follows the coil. If the misfire follows the coil, replace the coil.
2kg4u is offline   Reply With Quote
Old 04-12-2011, 11:28 AM   #3
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

When you pulled the plug, did it look any different from the other plugs? I've seen twice now a broken valve spring cause misfire, and still pass every test we threw at it until we removed the valve cover and actually looked at it.
Danthurs is offline   Reply With Quote
Old 04-12-2011, 11:38 AM   #4
Junior Member
Thread Starter
 
Join Date: Apr 2011
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
nmvettes is on a distinguished road
Default

Great idea, but I forgot to mention that this engine has only one ignition coil. Well what else??? Thank you.
nmvettes is offline   Reply With Quote
Old 04-12-2011, 11:41 AM   #5
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

Here'* what can cause a misfire, most of them you checked.

Bad coil, but you have one so not likely.
Bad dist cap, and or rotor, you swapped them
Bad plug wire, but you swapped them
Bad plug, you tried new ones.
Bad injector, you swapped them.
Bad injector plug, need to test that.
Bad valve spring, need to check that
Damage, such as chipped piston, need a bore scope to check that.
Danthurs is offline   Reply With Quote
Old 04-12-2011, 11:42 AM   #6
Junior Member
Thread Starter
 
Join Date: Apr 2011
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
nmvettes is on a distinguished road
Default

When I did the compression test, I did it whith the valve cover off to check the lift of the rockers and inspecting the springs. They look fine but I do not know if they could be weak. The engine runs fine in higher rpms but idles a little rough. Thank you
nmvettes is offline   Reply With Quote
Old 04-12-2011, 11:46 AM   #7
Retired Senior Admin

Expert Gearhead
 
Danthurs's Avatar
 
Join Date: May 2006
Location: Sheboygan Wisconsin
Posts: 29,661
Thanks: 0
Thanked 16 Times in 13 Posts
Danthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to allDanthurs is a name known to all
Default

Look around for vacuum leaks, like the EGR tube. That can cause problems as well. A bad spring of chipped piston tends to show up more at higher RPMs.
Danthurs is offline   Reply With Quote
Old 04-12-2011, 11:56 AM   #8
Junior Member
Thread Starter
 
Join Date: Apr 2011
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
nmvettes is on a distinguished road
Default

I have checked for vacuum leaks everywhere and cleaned and checked the egr valve. I'm not sure if an o2 sensor could cause this. I guess I'll check the o2. I do not think a bad o2 would affect only one cylinder but I would'nt be surprised. Thanks again...Mike
nmvettes is offline   Reply With Quote
Old 04-12-2011, 12:34 PM   #9
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

he should have vortec 350 which has an injector spider setup, it does not have indiviudual injectors to replace. it does have a kit you can buy to upgrade to individual injectors because the setup is problematic. the kits are expensive though so you want to be sure you know thats it before you lay out the cash.
http://www.amazon.com/Delphi-FJ10566...2622365&sr=8-1
jwfirebird is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Cadillac Escalade 06' gauge repair for instrument cluster Britro Cadillac 2 10-03-2011 06:29 PM
Misfire (P0306) on a '98 Olds LSS with L36 engine (fixed) ScottyB Oldsmobile 17 09-07-2011 05:18 PM
1999 escalade 1los10 Cadillac 1 02-24-2011 01:15 AM
P0301, p0302, p0303, p0304, p0305, p0306 Danthurs OBD-II Trouble Shooting 0 09-23-2009 11:12 PM
Consistent P0306 when cold - RESOLVED gm_jim 1992-1999 5 01-21-2008 08:18 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 07:22 AM.


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.