Ok guys...I need a little help here. I got a 1980 Z28 350, whenever im driving around and drive faster than 55, white smoke comes out of my exhaust. Now to give ya a lil back story, last summer i heard a clicking noise on the passenger side. Sounded almost like an exhaust leak. So trying to be optimistic and thinking its a simple job...i got better connectors for my headers to the exhaust...well sound was still tehre...did a compression check...everyhthing was perfect. Now we took the valve covers off..and checked the lifters and rods...well they were wayy off, and turns out my cam is wearing down on the last 2 lobes..so we tightened the lifters down, everything is solid, no more cam problem either...but still...after 55 mph white smoke is coming out...and im afraid to drive much more in case something give..Any Ideas!?!?

please help out!

mike

 

White smoke is usually coolant getting into the combustion chamber and can be a cracked head or a blown gasket.

Could be a small leak and the pressure is just pushing it through at higher RPM's due to heat build up. That's just a guess though. If it's dual pipes on the back without a crossover, which side is it coming out of? Take the car out really quick, let it build up heat just enough, do a quick 55+ to get the smoke and come back and park it. Pull the plugs on the side the smoke comes from and see if any of them are wet. You could also do a compression test.

 

its dual exhaust and coming out both sides...when i did a compression check i think it was 150 in each chamber...i think i might have a cracked head, so im just gonna take it all apart this winter and see whats wrong

 

Don't pull the motor a part on a guess. Borrow a coolant pressure tester from autozone. First see if the system holds pressure. If not and you have no external leaks pull the plugs and see if you have coolant in the cylinders. Second start the motor with the tester hooked up and no pressure. See how quick it builds pressure. It should take several minutes before you see pressure build. If it builds and holds real fast you could have blow headgasket of craked head.

Also if you just pull your plugs you should see a green tint to the plug(s) that are seeing coolant.

Now both Kuphur and I are assume a certain type of "steam cloud". If it more of a smoke then white could mean lean condition. Meaning your carb/fuel pump is the issue. If its a light blue smoke you could have a problem I used to see all the time. The oil return holes are sludged up and the valve covers are filling with oil. The seals are not designed to stop a flood of oil only a spary and you get smoke at cruising speed.