On startup my 305 smokes and will smoke if I give it some gas. Could it be the valve seals? Do you have to remove the heads for this job and how hard is it to do? Could it be something other than the seals? Thanks.

 

I was told it's valves seals, some people say that by switching to Mobil 1 synthetic oil the smoke went away.

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'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
FLOWMASTER, NO CAT
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
3:73 Posi
Rebuilt 700R4 vette servo and .500 boost valve
B&M Megashifter, 5" Autometer Tach w/shift lite
Soon to be installed
3" Hooker Aero Chamber

 

i have the same problem, and i switched to mobil 1 tri synthetic blend (15-50) and for a while there the smoke at start up and WOT went away, then it came back and now it just seems worse, im having this problem too. i guess its the crappy heads gm put on these cars....

 

my 83 trans am does this also but after a few it goes away my dad and i put in some 110%octane to help clean out the carbon in the old engine and it helped a bit after asking around we found just about the same answer leaky valve guide u have to take off the heads to fix this and while your at it spend some extra and get em souped 2

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CHRIS
1983 firebird transam

 

it could be either valve guides or valve stem seals. the guide is the part of the head where the stem of the vavle ride through. if that is whats worn, the heads need to be removed and taken to a mchine shop, in which case you might as well just get a set of rebuilts. if its the seals, you can change them on the car but it's still a pain in the *** .

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85 Z28- 350, Comp 262, Edelbrock Performer intake, Edelbrock 600 cfm carb and Edelbrock cat back, Summit headers and vette servo
-JVC, Eclipse, Pioneer, MTX, Phoenix Gold, Planet Audio