White smoke at startup, 2004 Chevy Avalanche 5.3

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I bought a 2004 Chevy Avalanche 5.3 recently. It has 200K miles. I was impressed how well it seemed to have been maintained and cared for. Garaged, not a scratch on it, etc. Owned by an elderly man who I presume babied it.

It runs great, but upon cold start up it emits white smoke for about 1-2 minutes at idle. After that, it stops completely. I have surfed the net, and I see there are multiple causes that could be doing this. I am confident it is not condensation. It happens every time, even if its 100 degrees outside. It does not smoke during warm start ups.

It consumes more oil than I thought it would. I add a quart every 1000-1500 miles. Oil remains perfectly clear. I am running 10w-30 SuperTech High Mileage Synthetic, NAPA Gold filter. Opinions and advice are welcome. Thanks.
 
These engines have an issue with some heads from one supplier, which become porous or crack, and allow coolant into the oil. Start a routine of checking the level of coolant in the overflow tank on a regular basis at the same time (first start of the day, when it has sat overnight), and monitor the level.

My mechanic had a head fail on their 2005 Silverado, which is their shop truck, at 160,000 miles.

There is also a known issue with the driver's side valve cover, which can lead to increased oil consumption.

If you aren't already familiar with used oil testing/oil analysis... now might be a good time to do so.
 
I bought a 2004 Chevy Avalanche 5.3 recently. It has 200K miles. I was impressed how well it seemed to have been maintained and cared for. Garaged, not a scratch on it, etc. Owned by an elderly man who I presume babied it.

It runs great, but upon cold start up it emits white smoke for about 1-2 minutes at idle. After that, it stops completely. I have surfed the net, and I see there are multiple causes that could be doing this. I am confident it is not condensation. It happens every time, even if its 100 degrees outside. It does not smoke during warm start ups.

It consumes more oil than I thought it would. I add a quart every 1000-1500 miles. Oil remains perfectly clear. I am running 10w-30 SuperTech High Mileage Synthetic, NAPA Gold filter. Opinions and advice are welcome. Thanks.
I noticed some oil consumption on my high mileage 5.3 on long, high-speed highway trips. I switched from 10w-30 to a European 0w-40 oil and it curbed the consumption. I used the 0w-40 because I got a good deal on it. Next time I'm going to use 5w-40 because it's cheaper.

I do not have any white smoke on startup, whether it sits for an hour or a week. Some white steam when it's cold is normal though!
 
My 05 4.8 blows whitish blue smoke occasionally on cold starts or occasionally on hot soaks only on hot days. I'm fairly confident it's valve seals because I have to pull the plugs and clean valve seal oil deposits off them every 20k or so. Running high mileage oil the last few changes has maybe reduced the occurence, will see how the fresh plugs are holding up in another 10-15k.

Mine uses no coolant, so it's not a cracked head (knock on wood). Oil stays clean all through the oil change interval. It has historically used a qt every 2-3k miles (with lots of idle time). If yours is using it in 1-1.5k and the smoke lasts that much longer, it's probably just that the valve seals have gotten that much worse than mine are.

The couple mid 2000s 5.3s that appeared to have a cracked head, I saw in the express lube back when I worked there, it was obviously going into the oil, because it drained out in chunks.
 
Valve stem seals being old/stiff. Add some ATP AT-205 or LiquiMoly Oil Saver to help restore them. They may be damaged at this point and need replacing to truly solve the problem - so instead you can run heavier weight oil to help.

Valvoline HM Maxlife works too. I like, use and recommend Supertech but the Valvoline HM is just much better than the HM version of Supertech in my experience.

EDIT: you may have lots on crud on there too by now - add 1oz per quart of oil in crankcase Gumout Multi-System (something PEA aka Techron based). Or B-12 Chemtool, MMO, or Seafoam if you are oldskool. Or BG 109 EPR flush before next oil change if you are just kinda oldskool.

EDIT2: I do know oil smoke is usually blue-ish. This is condensation, maybe some fuel, and and oil from the leaky valve steams leaking into the cylinders.
 
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White smoke from a cold engine is totally normal, without looking at it I cant say it it excessive or out of the ordinary.
Pure guess works on my part but it could be a injector leaking. White smoke is a tell tale sign of that, increased oil consumption can also occur, as fuel dilution increases the diluted oil burns off faster.
This what I think may be happening, the injector sticks when it cools off overnight (I see this quite a bit it is common enough), when you start it the engine will bellow white smoke if its stuck wide open and much less if only opened partially.

Once it warms up a little it begins to operate normally and its all good till next time. Again white smoke is normal with a cold engine but at 100f it would be minimal.
I would check the cooling system and do an UOA in this case, look for high fuel dilution and evidence of coolant in the oil.

Something else you can try that cost very little and you dont have to do anything is put a bottle of Redline SI-1 and a can of Berrymans chemtool in a full tank of fuel. Both at the same time is fine. See if it makes any difference.

Edit: I personally would not put any sort of sealer in the oil for the valve stem seals or any other seal for that matter just yet, it could be seals or worn guides, sticking rings also. I would do a flush with Chemtool at idle only for 15 min at the next OCI to possibly help with sticking rings.
Piston soaking on V engines seems to be less effective than on straight engines.
 
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One more thing I forgot. Get some of that Lucasoil Synthetic Oil Stabilizer snot. It’s like 90 weight pure oil base. Add a quart. Idle for 10 minutes. If it cures/improves this on your next cold start, it’s definitely the valve stem seals. I don’t recommend using that stuff as a long term cure though, more of a diagnostic. Well on second thought at 200k miles maybe it is fine as a “cure”.
 
You should listen to Trav. He had the focus and discipline to address your concern (the smoke) without being led astray by wanting to fix the high oil consumption (like me). I can tell already he’s a top notch troubleshooter and I just “met” him.
 
Maybe remove the Injectors & send them to Trav?

I've had great luck cleaning the Multec II & Bosch Flex Fuel injectors found in LSx truck engines with GM top engine cleaner using a pressure vessel, You can not add it to the tank!!!

I also use GM top engine cleaner to soak pistons, It's best to get the piston close to BDC or at least far enough down so the cleaner covers the entire piston
 
Maybe remove the Injectors & send them to Trav?

I've had great luck cleaning the Multec II & Bosch Flex Fuel injectors found in LSx truck engines with GM top engine cleaner using a pressure vessel, You can not add it to the tank!!!

I also use GM top engine cleaner to soak pistons, It's best to get the piston close to BDC or at least far enough down so the cleaner covers the entire piston

Better yet, my daughter lives in Fort Worth. Next time we visit her maybe I can swing by your shop? Can you PM me the contact info /address? Thanks.
 
I've had great luck cleaning the Multec II & Bosch Flex Fuel injectors found in LSx truck engines with GM top engine cleaner using a pressure vessel, You can not add it to the tank!!!

I also use GM top engine cleaner to soak pistons, It's best to get the piston close to BDC or at least far enough down so the cleaner covers the entire piston

Can you give my truck this service?
 
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