99 suburban miss fire - Chevrolet Forum - Chevy Enthusiasts Forums

99 suburban miss fire


  Reply  
ekamm's Avatar
CF Beginner

Join Date: Mar 2011
Posts: 5
Derby Kansas

March 18th, 2011, 8:56 AM   #1  
99 suburban miss fire

I am a first time poster here and have an issue with my 1999 suburban, 4wd, 5.7L, 153K. The engine light came on the other day after it had been idling a little rough. I went have the code read and the guy said that it was a miss fire on #6 cylinder. Are there any obvious things to check or look for? Is there a common issue that I should check first?

 
EinST's Avatar
CF Veteran

Join Date: Mar 2011
Posts: 1,706

March 18th, 2011, 6:16 PM   #2  
Do a web search for trouble code P0306? It basically means cylinder #6 didn't contribute enough to the crankshaft output. Check for the usual suspects such as ignition and fuel injection components, and compression on that cylinder.

 
loneViper's Avatar
CF Beginner

Join Date: Feb 2011
Posts: 3
Great Falls, MT

March 19th, 2011, 6:44 AM   #3  
I know this is gonna sound strange but my 99 Suburban had the exact thing and it turned out to be a leaking intake manifold gasket. apparently the Dex cool antifreeze ate the gaskets out. The problem was fixed with new gaskets and green antifreeze.

 
shamrock246's Avatar
CF Senior Member

Join Date: Feb 2011
Posts: 345
Middletown DE

March 19th, 2011, 8:30 AM   #4  
got that problem after changing/upgrading the intake manifold gaskets it turnout being a stuck poppet valve in the fuel injection spider i did the spider upgrade and cleaned the mass airflow sensor and it runs great now the fuel injection spider upgrade is worth every penny,check for spark and compression


Sean
1997 burb

 
ekamm's Avatar
CF Beginner

Join Date: Mar 2011
Posts: 5
Derby Kansas

March 20th, 2011, 12:39 PM   #5  
I have been losing coolant as well but no leak visible. So I guess that it is possible but how to tell for sure ?

 
73shark's Avatar
Administrator

Join Date: Apr 2006
Posts: 9,196
KC, MO area

March 20th, 2011, 9:36 PM   #6  
Check around the water pump weep hole. If it's not coming out there, then it is either going into the crankcase or combustion chamber. Neither are good options.

 
legolas894's Avatar
CF Junior Member

Join Date: Jul 2009
Posts: 52
Ridgeway, Ontario, Canada

March 20th, 2011, 10:24 PM   #7  
Posted By: loneViper I know this is gonna sound strange but my 99 Suburban had the exact thing and it turned out to be a leaking intake manifold gasket. apparently the Dex cool antifreeze ate the gaskets out. The problem was fixed with new gaskets and green antifreeze.
I'm going down this road too. Can I ask you what it cost for that work? I was told $800. They do a couple of these every month.

 
73shark's Avatar
Administrator

Join Date: Apr 2006
Posts: 9,196
KC, MO area

March 20th, 2011, 10:28 PM   #8  
If the antifreeze is getting in the oil for very long, then there'll be more to fix than just the gaskets.

 
loneViper's Avatar
CF Beginner

Join Date: Feb 2011
Posts: 3
Great Falls, MT

March 21st, 2011, 6:16 AM   #9  
It's been a while since I had ours done but I do think it was in that $600 range. Course the Dex cool had to be flushed and green anti freeze installed. There is also a significant amount of labor. It deffinately cured the problem though. It would only be a matter of time before it got into the oil.

 
Tags
Search this Thread
Sponsors
Related Topics