Engine smokes blue smoke initally then none

76 CJ with a 304. Engine smokes (blue smoke) upon initial start then no smoke. What seal has gone bad in the engine. Or is it a piston ring issue?

 

Sounds like rings, but try this------find a long down hill road, get up a bit of speed at the top, and get clear off the gas on the down slope, then about half way, get back on the throttle.

If there is a big puff of smoke, your valve guides/seals are bad.

 

How about doing a compression test?

http://www.earlycj5.com/forums/showthread.php?t=78788&highlight=compression+test

If you add oil and the compression goes up, it's the rings.

 

A puff of blue smoke upon start-up is typically a sign of worn valve stem seals. GM small block engines of the late 70's and 80's are known for this.

Not really a big deal oil is just seeping by the seals while the motor sits and burning upon start-up. You can fix em if you want but again it really is no big deal. Although kind of a PITA (although not terribly difficult) to fix.

 

Valve Guide Seals X2,
If it really bugs you, it's a pretty straightforward fix. Get a fitting that screws into your spark plug hole and hooks up to your air compressor. This way toy can compress the engine and the valves wont fall into the cylinder when doing the repair.

 

nylon cloths line through the plug hole crank by hand till it stops change the seals remove the line....

 

:tea:

Great iea,,but what can I say,, I never pass on the oportunity to buy a new specialty tool,,,good thing the wife understands my addictions!

 

myself I never pass on making due with what i have...whaddya mean a screwdriver is not a pry bar it has a point dont it...

 

Bring the cylinder you're working on to TDC will help from dropping a valve in the cylinder also. Just follow the distributor firing order.