when i cold start my 85' elky 305, i get a blue/grey smoke coming out of the exhaust it stops almost instantly only a puff of smoke i was wondering what caused that?? i think i might be burning oil if so how do i fix it?

If the engine has 113,xxx miles on it your probably got worn valve seals(which would be atributed to nonconsistant maintanence). Also with it's age,it could be increased clearance between the pistons and cylinder walls on a cold start,but as the metal expands,it closes the gap. More than likely though,it's the seals.

Theres no real quick cure besides changing the seals. If it gets worse(i.e. constant smoking)then you'll have to change them. I wouldn't worry to much about it. Just be consistant with the oil changes and monitor the oil level in between.

I agree with Coldbastard that the seals are probably bad. However, the guides are probably not that good either. New seals will slightly band-aid worn guides.

thanks for the help. since its started its gotten worse but its not smoking constantly. i was planning on swapping in a motor anyways and almost have enough saved so hopefully the tRUSTY 305 will hang in there until then.

more than likely, it is your EGR valve. After fixing a bunch of **** in my engine, I hadn't gotten to that, and when I finally looked it up, that turned out to be the cause. I got it fixed, and since I have seen no blue/gray smoke (like what you explained). Just replace it, and it will also cure a good portion of any rough idle you might have.

Do a compression check on the engine. More then likely it is your valve stem seals but it could be worse, the engine may just be old and tired and it may be time for a rebuild or an upgrade. If it is just your seals, you can have the heads rebuilt (seals and a valve job) and it'll last you a while longer.