Blue smoky start up

[SPEJ04]

Hi yall. New guy here. I recently came up on a very low priced 2004 tahoe with about 188000 miles on it. Body in great condition and drove fine so i grabbed it. Did all the usual,changed all fluids and tuned up under the hood( plugs wires pcv,etc). I got a new job not too long ago which lengthened my commute from 3 miles to 12 one way and the weather got hot. On the first day back from work after the new day trip it blew out hella blue smoke when i started it up. Never did it before. First thing i thought was pcv but id already switched it . Fixed orifice. Tube and all. Checked throttle body and intake and theres oil in there. But it only does it when its hot outside. Im thinking of all the culprits from bad gaskets to piston rings to everything and im just trying to find a direction before i start tearing crap apart. Intake is coming off and getting cleaned regardless. Running 5w30 royal purple

 

[SPEJ04]

Hi yall. New guy here. I recently came up on a very low priced 2004 tahoe with about 188000 miles on it. Body in great condition and drove fine so i grabbed it. Did all the usual,changed all fluids and tuned up under the hood( plugs wires pcv,etc). I got a new job not too long ago which lengthened my commute from 3 miles to 12 one way and the weather got hot. On the first day back from work after the new day trip it blew out hella blue smoke when i started it up. Never did it before. First thing i thought was pcv but id already switched it . Fixed orifice. Tube and all. Checked throttle body and intake and theres oil in there. But it only does it when its hot outside. Im thinking of all the culprits from bad gaskets to piston rings to everything and im just trying to find a direction before i start tearing crap apart. Intake is coming off and getting cleaned regardless. Running 5w30 royal purple

Not sure if im adding on right but i just want to point out that mileage aside this truck was treated well. Had to replace some evap stuff but it was and still is smooth. No eng lights no codes.

 

[OBSandaNNBS]

Welcome and sorry it's giving you problems...smoke disappears after running or is constant after warmup?

 

[Scottydoggs]

sounds like bad valve seals to me. when the oil gets hot it becomes thinner, and can pass past the valve seal when they are worn out, then it pools in the cylinders or on top of the valve and you crank it up and she blows blue smoke then stops. most of the time when they are bad it will smoke on every cold start.

with 180K plus miles new seals and new valve springs is not a bad idea. as long as you have to take the springs off, may as well change em. dont have to, but they do lose their spring rate over time and miles and thousands of heat cycles. then the valves can float even easier. making the engine live up the chevy acronym, "can hear every valve yelling".

 

[justirv]

Not sure if im adding on right but i just want to point out that mileage aside this truck was treated well. Had to replace some evap stuff but it was and still is smooth. No eng lights no codes.

How long it sat before the time it went blue can be an indicator. Check to see if you can repeat the blue while downshifting into 2nd (at an appropriate speed). When downshifting, the added vacuum can pull oil into the cylinders and indicate worn valve seals, which can also be seen on start up.

 

[homesick]

Valve seals definitely come to mind, but it seems like there's a factor missing.

Going from no smoke to "hella" smoke, from one start-up to the next start-up, sounds pretty odd to me.

joe

 

[TJ Baker]

it blew out hella blue smoke when i started it up.

What engine?

If applicable look into the known head cracking issues with the Castech 706 heads.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

 

[SPEJ04]

Dis

Welcome and sorry it's giving you problems...smoke disappears after running or is constant after warmup?

It disappears pretty quick but it seems to be getting worse. Just did it out of nowhere one day and now its a constant occurrance when its sat arpund in hot weather all day

 

[SPEJ04]

What engine?

If applicable look into the known head cracking issues with the Castech 706 heads.

Its got a 5.3. Ill have to look i to that thanks

 

[SPEJ04]

Valve seals definitely come to mind, but it seems like there's a factor missing.

Going from no smoke to "hella" smoke, from one start-up to the next start-up, sounds pretty odd to me.

joe

Yeah. It just started doing it out of nowhere. But from all the research ive been doing i think your suggestion is correct. Thanks

 

[SPEJ04]

How long it sat before the time it went blue can be an indicator. Check to see if you can repeat the blue while downshifting into 2nd (at an appropriate speed). When downshifting, the added vacuum can pull oil into the cylinders and indicate worn valve seals, which can also be seen on start up.

Ill give it a shot thanks man!