mogulmasher
Registered Member
My '77 K20 is starting to blow blue smoke out of the passenger side tailpipe. Guy that restored truck traded it at used dealer I bought from, so engine history is little unknown. Claim was that it had less then 5000 miles.....I believe it, engine was very clean.
It runs strong now that I've dialed it in a little better. About a month ago it billowed blue smoke out rt exhaust pipe from time to time for just a few minutes after being fully warmed up. Now its doing it pretty much all the time. It smokes lightly all the time and from time to time billows pretty good, but only for a minute or so then back to lightly. When I run it at 55 or 60 and floor it, there is light smoke under accelration, then let off and nothing, then get back on it and there is always a big puff then back to smoking lightly.
There is no puff of smoke at cold start up, so I'm thinking its not valve seals. Truck had a holley truck avenger on it that was running horribly rich...was getting like 6 or 7mpg's, now there is a edelbrock 600 on there and its running much better and getting 10 mpg's. One mechanic suggested the rich running holley might have washed the oil with fuel and might be causing problem.
My thought is, especially since the guy that built this truck has done a few rookie mistakes, is that a intake gasket has torn because of the aluminum intake with the iron heads. What do you guys think?? If not this guess it might be a broken ring.
It runs strong now that I've dialed it in a little better. About a month ago it billowed blue smoke out rt exhaust pipe from time to time for just a few minutes after being fully warmed up. Now its doing it pretty much all the time. It smokes lightly all the time and from time to time billows pretty good, but only for a minute or so then back to lightly. When I run it at 55 or 60 and floor it, there is light smoke under accelration, then let off and nothing, then get back on it and there is always a big puff then back to smoking lightly.
There is no puff of smoke at cold start up, so I'm thinking its not valve seals. Truck had a holley truck avenger on it that was running horribly rich...was getting like 6 or 7mpg's, now there is a edelbrock 600 on there and its running much better and getting 10 mpg's. One mechanic suggested the rich running holley might have washed the oil with fuel and might be causing problem.
My thought is, especially since the guy that built this truck has done a few rookie mistakes, is that a intake gasket has torn because of the aluminum intake with the iron heads. What do you guys think?? If not this guess it might be a broken ring.
