• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

Drew

Full Member
Joined
Oct 25, 2020
Messages
52
I have white exhaust smoke, no oil discoloration and car does not overheat. Engine slopes, service traction system, abs light, check engine, code p0306. Replaced all 8 spark plugs, replaced ignition coil 3rd in left side I believe is cylinder 6. Any help is greatly appreciated, thanks.
 
White smoke = Coolant burning
Blue/grey smoke = Oil Burning
 
White smoke = Coolant burning
Blue/grey smoke = Oil Burning
Sounds like you may have what I had...to a degree. My heads developed a crack causing two unfortunate results... (1) coolant getting into my oil and (2) coolant getting into my exhaust. Fortunately I caught it soon enough as I monitor my truck fluids closely and was able to put on new heads. The gaskets showed some signs that contributed as well. Does yours look like this?
 

Attachments

  • 20200504_165543.mp4
    4.1 MB
My lifters began to clickety clap as well...fortunate to catch it early. It was a little work to get repaired, but its been running well since.
 
Sounds like you may have what I had...to a degree. My heads developed a crack causing two unfortunate results... (1) coolant getting into my oil and (2) coolant getting into my exhaust. Fortunately I caught it soon enough as I monitor my truck fluids closely and was able to put on new heads. The gaskets showed some signs that contributed as well. Does yours look like this?
Yes exactly like that.
 
Yes mine smoke exactly like that, I'm not losing fluid but I topped off before these problems began, checking all fluid levels.
 
My lifters began to clickety clap as well...fortunate to catch it early. It was a little work to get repaired, but its been running well since.
I hear clicking I think it's the sound of the misfire on cylinder 6 code p0306.
 
you may be flooding cylinder 6 with coolant, misfiring it and then smoking our of your exhaust. #6 plug show signs of water, or does it smell like antifreeze when you remove it?
 
My lifters began to clickety clap as well...fortunate to catch it early. It was a little work to get repaired, but its been running well since.
I hear clicking I think it's the sound of the misfire on cylinder 6 code p0306
you may be flooding cylinder 6 with coolant, misfiring it and then smoking our of your exhaust. #6 plug show signs of water, or does it smell like antifreeze when you remove it?
It looked corroded, I didn't check for odor but I will. Sounds like my head gasket then?
 
I hear clicking I think it's the sound of the misfire on cylinder 6 code p0306

It looked corroded, I didn't check for odor but I will. Sounds like my head gasket then?
Thank you
 
No he is saying a possible cracked head.
 
A spark plug looking "corroded" is a good sign of coolant getting into the cylinder.

Fuel or oil normally would not do that.

Water (coolant) getting into the cylinder will have a tendency to "steam clean" the spark plug, where too much fuel or oil will left dirty black deposits.

Light tan deposits are normal.
 
cracked head is more likely than a gasket...either way, you will have new gaskets and head if you get into it. I suggest installing new hydraulic lifters while your in there, the cost is minimal for the amount of work to get down to the block. Our aluminum heads are renowned for developing small cracks. Post a pic of that spark plug, there are enough folks on here with experience that should be able to help determine if it is being flooded with coolant. As far as the cracked heads, mine was bad enough to see with my eyes once I removed the valve covers. You may be able to perform a pressure test by pressurizing your coolant system and seeing if it holds pressure, but based on your exhaust smoking, it would just be a formality.
 
cracked head is more likely than a gasket...either way, you will have new gaskets and head if you get into it. I suggest installing new hydraulic lifters while your in there, the cost is minimal for the amount of work to get down to the block. Our aluminum heads are renowned for developing small cracks. Post a pic of that spark plug, there are enough folks on here with experience that should be able to help determine if it is being flooded with coolant. As far as the cracked heads, mine was bad enough to see with my eyes once I removed the valve covers. You may be able to perform a pressure test by pressurizing your coolant system and seeing if it holds pressure, but based on your exhaust smoking, it would just be a formality.
I look for other signs of a cracked head such as over heating and milky looking oil, none found.
 
you may be flooding cylinder 6 with coolant, misfiring it and then smoking our of your exhaust. #6 plug show signs of water, or does it smell like antifreeze when you remove it?

you may be flooding cylinder 6 with coolant, misfiring it and then smoking our of your exhaust. #6 plug show signs of water, or does it smell like antifreeze when you remove it?
I found I have collapsed lifter on cylinder 6 (AFM lifter). I replaced it in process of wrapping up head gasket replacement. Didn't know these Avalanches have AFM, DOD and VLOM. Need a DOD delete.
 
I found I have collapsed lifter on cylinder 6 (AFM lifter). I replaced it in process of wrapping up head gasket replacement. Didn't know these Avalanches have AFM, DOD and VLOM. Need a DOD delete.
How'd it go Drew? There are DOD delete kits out there.
 
How'd it go Drew? There are DOD delete kits out there.
I replaced the single lifter, could not afford all 16 though I wish I had done all AFMs (1, 4, 6 and 7). I cleaned and polished the heads and block, replaced head, intake manifold and valve cover gaskets, now it purrs like a kitten, no more white exhaust smoke. Apparently DOD deletes involve changing out your camshaft to accommodate non DOD hydraulic lifters. I think the DOD delete is inevitable for all Avalanche owners.
 
I replaced the single lifter, could not afford all 16 though I wish I had done all AFMs (1, 4, 6 and 7). I cleaned and polished the heads and block, replaced head, intake manifold and valve cover gaskets, now it purrs like a kitten, no more white exhaust smoke. Apparently DOD deletes involve changing out your camshaft to accommodate non DOD hydraulic lifters. I think the DOD delete is inevitable for all Avalanche owners.
Glad you got it...Im also glad mine was built before all that extra fun...
 
Back
Top