Smokey

[Bert]

One of my Festys suddenly began to continuously plume smoke a few months ago. The timing belt had 'let go' just before all this but I knew it was a non-interference engine. Compression check was informative in that wet/dry on all 4 cylinders was good (165 lb) but #2 was not consistent and went as low as 60. Prognosis by a seasoned mechanic was a sticking valve. Nice story but this has never happened to me before.

Never done this either before, to an old engine, but I poured in a half can of 'seafoam' and ran it down the highway for 2 km in 2nd gear at 6000rpm and then highway drove it for 1000 km after (Christmas holidays).

Motor runs great now and oil consumption has dropped like a stone.

You don't normally advise people to 'beat the crap out of an engine, do you?

[MasterTec]

There was probably build up on a #2 valve from a leaking seal preventing it from closing all the way intermittently. The seafoam loosened it up and the build up broke apart allowing it to run more properly now.

It will probably eventually happen again but for the time being enjoy the good running engine and keep an eye on the oil consumption.

[Movin]

why bother with the sea foam ?
run er on up to 7 or 8 and it'l set the plug gap
to specs too !

[WmWatt]

If you remove the valve cover gasket and turn it over you might see carbon deposits above #2. That's how I knew my exhast valve was not closing properly. Carbon deposits on the valves, if not removed, can crystalize and harden. In my case chemical solvent disolved the hardened carbon and restored the valve to normal operation.

[Movin]

right on ^^^
whether you pull the engine down or do it running, either way heat and chemical is what it takes to get parts clean. Even my hot water parts washer has some serious detergent in it. If you do the running method be aware that the procedure usually doesn't do seals any good. Also flush out the pan and repeat the procedure if necessary until you are confident the oil sump screen is clean and unobstructed.
Follow that with a strong dose of carbon cleaner in the fuel to wash the softened carbon from the rings on out.