I have a 91 305, when I crank the car it blows a puff of white, may be bluish, white smoke out. When I crank it and when I take off, it does this, and only then. Not when I rev, not if I punch it, I checked the oil... It needs to be changed but it's not bad, no water, no residue, nothing. I don't understand why it's blowing smoke. The motor isn't burning oil, no leaks, nothing. Any suggestions?

 

valve seals oil leaking past while car is not running?

 

pvc valve on the valve cover

 

both of the above . but , more likely than not it's sludge build-up . remove valve covers , clean oil sludge from top of cylinder head and around valve springs . pay special attention to drain hole/passages at lwr. front & rear of cylinder head . they can/will sludge up and slow/prevent oil from draining back to crankcase from cylinder heads . slow oil drainage causes a bit of oil to seep into valve guides , hence oil smoke at start-up . it's a easy & cheap but very dirty job . even an amateur mechanic should be able to do it in a day . good luck .

 

Ok, how bad will it hurt the car? I'm not driving it often right now, maybe 1 time a week. If I were to run a motor flush through my engine would it cut the sludge? If I were to change my heads, like I'm planning on doing, would that work be necessary? Thanks

 

a good motor flush could/may help . (for sure it could not hurt) more likely than not it would take several flushes to clean it good . if your going to change heads soon just do a couple of flushes and hope for the best . it would not hurt to run as is , many people are . years back i bought a 1954 chev. that had been in a barn for 12 yrs. . only started a few times in that time period . brought a battery , oil filter & oil . started car , smoked liked a diesel , lifters ticked , etc. . flushed engine , better but not good . drained oil , strained oil through old "T" shirt , put drained oil back in flushed again . did that 3 times while friends/helpers were getting new oil & filter . got a little better each time . drove car home (200 miles) with 2 vehicle escort , minimal smoke & engine noise . had a fresh 327 waiting for her . long story but just proof that engines need clean oil . good luck .

 

K cool, I'll try the flush first, would be worth the 7$ before paying for new seals and down time right now. Thanks

 

When you change your oil add CD2 Oil Detergent -

http://www.amazon.com/CD2-4111-Oil-D.../dp/B000AM8C76

 

Add it to the oil with the oil, or add it to the oil and the. Change it?

 

4 quarts oil and 1 bottle CD2, will clean the inside of your engine CLEAN. You can do it every oil change untill it is as clean as you want it to be.

 

i wouldnt just replace your stem seals though, usualy theyll hold for a little while, but they often go bad due to bad valve guids, so youll have to do those too, or you can do like im doing now and just replace the whole for the comfort of having new ones