Low Mileage '88 Gmc With 5.7 Blue Start Smoke

[Focker]

I started with a search but didn't find any 5.7 smoke talk so here I go.

 

HISTORY:

I just got an '88 Sierra with only 49K miles (Yes 49).

 

ISSUE:

I go to work at 3:45am and drive one mile. When I start my truck anywhere from 6 to 9 hours later there is a puff of blue smoke that floats through the air...It doesn't smoke otherwise.

 

It's too dark in the morning to see if it does it every time so I just tried it this morning and it puffed.

 

Thanx in advance for your help!

[700 sportsman]

Valve seals? I'm not sure, but I have heard of these causing the smoking

 

and I thought I had a low mileage 1996 with 54,000

[grose67]

Probably valve seals. They let just enough oil slip past to make a puff of smoke. Not that uncommon.

[Nytemare]

Valve seals? I'm not sure, but I have heard of these causing the smoking

 

and I thought I had a low mileage 1996 with 54,000

Yup valve seals is the most likely culprit.

You could change them out on that engine without removing the heads. you could also try using some Rislone to see if it helps...sometimes it helps soften up the seals and allow them to seal again...but dont hold your breath.

You may have oil in your intake, or a busted PCV valve too...check them all. Clean the intake with some Seafoam and replace the PCV...see if it helps.

 

Worst case scenario...you have a cracked ring...easily discovered by doing a compression test.

[Focker]

Thanx for the ideas everyone...I'll start checking things out and keep you posted of my findings for those who are interested.