2005 silverado 5.3 smoke on start up

[lawdog]

Its got like 102,000 on it now. When I start it up, I often get a pretty big cloud of blue smoke. It doesn't smoke all the time but just a puff on start up, usually after sitting for a little while. I checked oil after about 2500 miles since a change and it was about 2/3 to 3/4 quart low, not a tremendous amount.

Should I be concerned? What can it be and what can I do? Does that Valvoline "max life" type oil do any good on higher mileage engies or is that just a scam?

[Jeremy airjer W]

Your still well under gm's oil consumption guidelines.

all Max life oil does is make the maximum impact on your wallet! If your paying more than $30 for an oil change your at the wrong place!

[delcecchi]

Isn't blue smoke on starting the classic sign of valve seals going? Had an 84 civic cvcc that ran great except for fogging the neighborhood in the morning when the kids left for school.

[PurpleFloyd]

I thnk it is a classic sign of a 5.3 chevy. Both my dad and brother have them and they both have done this as long as they have had them from what i remember and they were new or near new when they bought them.

[Eric Wettschreck]

Dawg, couple things.

Max life oil means max wallet drainage. Nothing more, nothing less. Don't waste your money.

Big ole puff of blue smoke outta the chev at start up is textbook valve seals leaking. If it smokes and goes away, no worries. Point her at the skeeter next and start her up.

Not really an issue. Big thing is don't waste your money on fancy labeled oil that doesn't produce..........aka Max life.

[Steve Foss]

I've owned a number of Chevy trucks with small-block V8 motors. And driven a bunch more. Ranging from almost new to 250,000 miles. Never met one that didn't smoke for a few seconds to a minute on start-up after sitting overnight or longer.

Tiny amounts of oil passing through the valve stem seals is what the Chevy mechanics always told me.

As already mentioned, if you're only going through 2/3 to 3/4 quart after 2,500 miles, I don't think you have any worries.

[Pistol Pete]

Hope yours lasts better than mine. Had an 08. Was fine till 65000 then started useing oil. From 70-74000 miles I put in 3 1/2 quarts....traded it

[lawdog]

Valve seals was my first thought too, but I didn't know if it could be something else. Never know with these new technologies. It only lasts a couple seconds, not much of an issue really I just didn't know the history on these motors if they were known for problems with this. It just started recently, I've never noticed it before the last month or so.

[Tator2k]

Valve seals is what I was told on my 02 Avalanche a few years ago.

[Scott K]

You would have thought, all of those years with the same issue, they may have thought about correcting them? No?

[Wallgeye]

At least you made it to 100K miles!! My 04 Silverado was on it's 3rd ENGINE (5.3L) by 40K miles! I smoked out the lakeville gander mountain parking lot one day when I started it up.

Original engine, water pump at 12k miles.

Blown head gasket and a hydraulic'd engine at 22K

Second engine lasted 6K miles, had a dealer ask me why I still had original oil filter on engine. (was my second oil change on this engine, guessing someone "forgot" to replace it) Different dealer then usual because of strike going on at my normal shop. Blown headgasket again.

Third engine went about 4k miles and on a Sunday afternoon after just passing Hudson, WI the engine suddenly started sounding like a diesel with the engine brake stuck on. No one open in Hudson, called my dealer, Service writer heard engine on the phone and told me to drive it back to him. He promised that he had never heard the noise before I pulled into the shop. (I was worried about driving it all the way to the west metro from Hudon like that for warranty purposes) Turns out this one had several rocker arms come loose!

I lemon-lawed the truck and got my money back. I loved the truck, had the quadra steer option on it that I hated to part with!

Current truck (08 Sierra) still has original engine, but I cannot seem to keep brakes in this one. Rotors turned at 12k, needed front brakes because 1 pad was worn down to nothing at 24K miles and I needed the rotors turned again!

If it's not one thing, it's another....

[timjones]

I have a 2002 Silverado with the 5.3L and have absolutely no complaints. Have the oil and filter changed every time the little [PoorWordUsage] display tells me its time. Check the oil a couple of times between changes and have never had to add any oil. Never smoked. Coming up on 150K miles.

[SpecialK]

Current truck (08 Sierra) still has original engine, but I cannot seem to keep brakes in this one. Rotors turned at 12k, needed front brakes because 1 pad was worn down to nothing at 24K miles and I needed the rotors turned again!

If it's not one thing, it's another....

That sounds like a sticky caliper or a faulty ABS valve to me...

[bassmann77]

How is your coolant levels? I had the same thing going and both of the heads were cracked. Chevy had a bad casting with the Castech heads. It is common from the 04-07 Chevy truck models. If it is the heads, get them repaired at a Chevy dealership and try to have them pay for it. Chevy knows about the issue and they will respond to letters and having it done at the dealership helps with the issues. Make sure if it is the heads, they are the Castech. Just google this information and there is a lot of pictures of how to identify the Castech heads.

[TLOz28]

I had the same problem on my 6.0 ( just a larger version of the 5.3 and the 4.8 LS series engine) I tried new valve seals but that was not the problem. The smoke is caused by a small amount of oil accumulating in the intake manifold or in the drivers side valve cover where the PCV hose connects to the valve cover. If you remove the driver side valve cover, on the inside you will see a metal plate that is fastened to the valve cover. Do not try to remove this cover. The problem is that the channels behind this plate and the drains become clogged with carbon and oil deposits. The channels are meant to allow the oil vapors and mist to condense and then drain back to the crankcase. When the channels and drains become clogged, the engine will pull too much oil mist into the intake or it will puddle right inside the channel area inside the valve cover instead of draining back. The valve cover won't appear to be stopped up because you can actually still blow through it, don't let this trick you, that will be the problem. You can clean this out either by soaking it in carb cleaner (soaking type that comes in buckets) for a few hours, or if you have parts cleaning tank, let the solvent run through the pcv port for a while and then carefully blow it out. Make sure you blow out all the drains in the cover, especially the 1/8" hole right below the pcv hose port. Also you can by a new aftermarket valve cover for this engine that comes with a new gasket for around $80.00. Hope this helps. I've got 406K on my 6.0 and this is the only problem I've had with the engine. I always use either full synthetic or the blend oil.