The Stovebolt Site Forums The Shop Area Engine Shop 235 Smoke Signal Interpretation.

Got the engine to run for more than a minute yesterday, and odd things happened.

Yesterday, the oil filler cap was bouncing like a tea pot lid and I had oil smoke coming out of these vents on the valve cover. Valve Cover Vent? There are two of these on each side of the valve cover, evenly spaced. Now my 4400 also has a 1953 235 in it, and the valve cover does not have these vents.

Second sign, No smoke from the road draft tube. (Clogged up?)

Third sign: Smoke Signal I assume this means that I either need rings, or valve seals.

Basically, what's up with those valve cover vents? The oil filler cap is late model, not the kind you might expect on a 1964 Chevelle 230, for instance.

???

Now that I think about it, there may be some water in that smoke, but it sure smells like oil.

starkweatherr,

The top end is common with the lower end through holes in the lifter area. The smoke coming out the top and out the tailpipe sure indicates a real bad cylinder, broken piston or blown head gasket.

Is it more steam than smoke. Does it dissipate like steam or trail away like smoke.

A compression test would give you instant insight into this mystery.

I must say I have never seen valve cover vents like that either.

Stuart

The 1954/55 valve covers had those slits in them. During those years the oil-filler cap was flat and solid (the cap had no vents/filter).

It looks like it's a 54 valve cover then. I'm not surprised. Do you know if there was any screen inside the valve cover or anything. I mean this truck didn't have the optional oil filter, so I'm sure there is plenty of dirt in it. Don't know why I'm worried about dirt getting in through the slots.

Seems odd that there isn't anything coming out the road draft tube. I thought that, even without the truck moving to create a small vacuum at the end of the tube there would still be something coming out.

I'll keep an eye on the radiator level.

The smoke lingers for a while, but does look awfully white. It seems to smoke a little less every time we run it, but we've probably only put half an hour on the engine since we've had it. I just can't see running it very much until I can get it to idle at less than 2000 RPMs.

if this is an engine that's sat for a long time, the smoke isn't a suprise, coming from the top, likely bad valve seals, or stuck rings - may work itself out but as likely needs a rebuild

Bill

I agree with doing a compression test. Then try it with a squirt of oil in the cylinders.

The road draft tube is mostly likely plugged also. Mine was and I cleaned it out.

Yes mine was clogged too took it out, cleaned it all and repainted it now it works functions great!! Peter

I've got a compression gauge, and a fully charged battery, thanks to the new alternator. I was thinking about running if a little more, after some oil through the spark plug holes, and see what happens.

The big problem now is the carburetor.

But, speaking of the road draft tube, I understand that there is a screw or bolt that I need to take out to release it. Can anyone refresh my memory on that.

There is a metal strap on the down pipe that is bolted to the pan/block (I forget which). This strap seems to be commonly broken or entirely missing. Once the strap is unbolted, the draft tube is just pressed into the block (and can usually be knocked out with a rubber mallet).

I wouldn't condemn an engine until you run it in after a long time off the road. It takes things a while to "clean up" and "reseat". I would get it tuned a good as you can and work it some before taking any drastic steps,
Scott

Thanks, Scott. I can't afford to rebuild it right now anyway. It does seem to be getting better the longer I run it, though.