Am seeing white smoke when I first start the car, and when I romp down on the accelerator. Don't see any while driving normally. Just had valve stem selas replaced. Compression and leak down tests revealed no problems. Fuel mixture too rich???

 

white smoke is water. so if you're lucky it's just condensation and not to worry. water usually is a problem when hot (underpressure). So if no problems hot and not loosing water I'd ignore it

 

Any chance it could be caused by the lead additive I put in the gas?

 

i never used any, wouldn't know. sorry

 

Well white smoke is always oil. If it isant the valve guide seals then its rims. Sometimes when you rebuild the heads they are too strong for a loose bottom and this will cause white smoke. If its an automatic then it may be a bad mogulater valve on the tranny sucking oil in through the vacume line. Pull vacume hose off at intake and ck for oil in the line. It could also be that you have valve covers with no oil baffel over the pcv hose intake. Hope this helps

 

White smoke is not always oil. Blueish colored smoke is oil. If its faint, it can appear white. White smoke is condensation and could be a blown head gasket or just happen when its could outside.

 

White smoke and blue smoke can be mistaken, but the smell will usually reveal what is causing it.
I believe you could have good compression and still burn oil if the oil rings are weak. Check the plugs for fouling or if they appear steam cleaned.

 

why would you do a thing like that?

 

Older engines that do not have hardened valve seats neat lead additive, because they were desinged to run on leaded gas. Damage can result from running it on unleaded gas.

 

as for valve seats, i had harden seats put in.