Well, I checked the oil drainbacks on my 352 and they were completely plugged with the remnants of my valve stem seals. The combo of a plugged drain and no more seal is probably the culprit. This engine has also been blowing oil out of the breather.

 

How do you think 8 firing right after 7 has ANYTHING to do with plug fouling? I think this info was pulled directly out of the bears a s s.

 

Amen on the camaro gumming all up had an 87 RS V6 3.8 I used 20/50 GTX and changed oil 2500-3000 only had 43,000 and need to replace a pcv plastic tube and needed to pull v-cover and OMG look like the motor top end had looked like it had been used in it that old 30wt. Motor oil and not running a thermostat letting it to run to cool causing it to build up sludge from the paraffin base oils from yesteryear. Hell I had 195* T-stat in it. It didn't smoke or notice it ever using or add oil between oil changes. But did read later about some Chevy's having that problem. Also some Mercedes doing the same..orich

 

Yep, those chunks of seal make nice little pieces of rip-rap in the drainback holes and help the sludge accumulate that much faster. Now you need an on-engine valve spring compressor, some 1/4 rope to put in the cylinders to hold the valves up, and a set of new seals- pretty easy with stock springs. It'll be a lot better just from cleaning out the drains, and just that much better and easier on a quart of oil if you opt to do the seals too
Congrats on being another person who was able to check and clean the drains without pulling the engine- that was the best one I've heard in a long time
Sounds like she's just a little tired, and you're getting a little blowby out the breathers- but your typical FE will usually still do a lot of chuggin' when it's a little tired

 

I think my 390 in my 74 is suffering from this very same issue. It smokes out of the drivers pipe (true duals) when idling. I pulled the valve cover and found chunks of black "stuff" all in the heads, and the oil drain back ports. Cleaned em up, and it still smokes a bit...but not like it was before.

Gonna run a few oil changes through it, buy a master gasket set and pull it apart. She's a leaker, and I can't stand one.

 

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