Question about smoking

[bck4more]

Ok so i bought this 1991 with 80k on it with the 5.7 runs pretty good my question is I changed the oil couple weeks back and used mobile 1 syn 5w30 and im noticing that after i drive it and shut it off when i go to restart it 10mins later or few hours later it will smoking on start up. Thats the only time it will smoke it never does it when starting up when engine is cold. Color of smoke? not real sure because the exhaust is dumped under the bed and its gone as fast as it comes. What do you guys think could be the issues rings maybe?

[Carder09]

Oil leaking from the valve cover's onto the manifold's? I would look around the engine bay for leak's, if it's already caked in old oil and grime, degrease the engine parts and then look for sign's of fresh oil.

[dsblue2000]

Assuming the smoke is coming out of the tailpipe and not under the hood, I was told once upon a time that this brief smoking on start-up was a bit of oil leaking past the valve guide seals getting burned off when it starts. It's still using oil but typically not as much as if it is a ring problem - you should watch your oil level to see how much. I also seem to remember there was a way to replace the seal(s) without removing the heads.

[bck4more]

Thanks for the info. Its def coming from the exhaust, the truck doesnt leak anything well i mean i see nothing in the driveway atleast.

[txab]

Valve guide seals are shot

[bck4more]

Valve guide seals are shot

Are those hard to replace

[dsblue2000]

Someone with more current knowledge correct me if I have something wrong here...

- remove rocker cover(s)

- one valve at a time, move crank until that cylinder is at tdc (so they are closed)

- use compressed air to hold valve closed

- remove valve spring, keepers, and replace seal

- put spring and keepers back on

 

you'll need a special tool to compress the spring, an attachment for your air compressor for the spark plug hole, and ideally a keeper remover

 

if you can find one plug that is oily, maybe you can get away with just replacing 2 seals but it is enough work to get all the other stuff out of the way to get the rocker cover off maybe not worth the risk.

 

here's one example of a link describing how to do this - there are several

http://www.enginebasics.com/Advanced%20Engine%20Tuning/Changing%20Valve%20Seals%20In%20Motor.html

[bck4more]

Ok thanks for the information. I started looking into this alittle more and seen where some people had said pull valve cover and check at the back to make sure the oil is draining down. Does that sound correct?

 

 

Someone with more current knowledge correct me if I have something wrong here...

- remove rocker cover(s)

- one valve at a time, move crank until that cylinder is at tdc (so they are closed)

- use compressed air to hold valve closed

- remove valve spring, keepers, and replace seal

- put spring and keepers back on

 

you'll need a special tool to compress the spring, an attachment for your air compressor for the spark plug hole, and ideally a keeper remover

 

if you can find one plug that is oily, maybe you can get away with just replacing 2 seals but it is enough work to get all the other stuff out of the way to get the rocker cover off maybe not worth the risk.

 

here's one example of a link describing how to do this - there are several

http://www.enginebasics.com/Advanced%20Engine%20Tuning/Changing%20Valve%20Seals%20In%20Motor.html

[dsblue2000]

Certainly worth looking at but less likely, I think. The drain holes are pretty good sized.

[bck4more]

Ok thanks for the help looks like ill be tackling this job before long