Packard Forum Index » V-8 (1955-56)

The smoke was definately blue on normal aceleration, but when my friend revved it, it was grey. It was shooting bits of acorn out the tailpipe on each rev, so im sure the mouse nest in the muffler was contributing to SOME of the smoke. My coolant level has not changed.

during the worst periods of smoking, it also sounded like it had a skip. It was definately not as smooth running either. It actually sounded like it did with the old crappy plugs that were in it when i bought it.

I have kept an eye on the road draft tube during all this, and have not noticed any changes in the amout or color of the smoke. Im not saying your wrong with the whole cracked piston thing Jack, though i hope you are, im just thinking that a catastophic failure like that would cause extreme blow-by, no?

Just got back from test drive. started in garage with no smoke. blew a little puff pulling uphill out of my driveway, but ran clean down the street. drove about a mile, then got on the highway to do around 50mph. no smoke on accel. utilized wide shoulder and decelerated with closed throttle all the way to a stop, then rejoined traffic. no smoke there. pulled in to the local mini-super and went inside for about three minutes. restarted car, with a little smoke. acelerated onto the street with a fair bit of smoke. This smoke burned off in about 500 feet, then did not smoke all the way home, which included highway merges, stops, starts, and hills.

Thanks for all the help so far, and if this road test data means anything, this is unfamillier territory for me.

I agree with Jack that it doesn't have the correct symptoms for a valve seal problem. Why not take a compression test first before you much deeper into it, and let us know the results. Also how about a manifold vacuum test at idle? How much vacuum and how steady is the reading? And how about running a rifle-bore cleaning rod down the oil return holes in the head - very important! These holes are not overly generous is size and if partially restricted you can get quite an accumulation of oil in the head which could then overwhelm the valve/guide clearance.

And one other thing to do first, take the vacuum line from the vacuum pump in the crankcase (joins to the vacuum block near the wiper motor) and remove it and plug the end. I think there's a very good chance that the check valve on the side of the block has failed and you're pulling oil from the crankcase vacuum pump directly into the intake manifold. Happened to me, looked like I was the mosquito exterminator coming down the street.

Comments about lack of lubrication to the valve area doesn't agree with observations on my 56 Caribbean with 90,000 miles. I don't know the entire prior history of the engine, but think it has never been opened. Though the car is a late one (#254) the engine is an early one (C-1137); it doesn't have the valve spring baffles and the valve area is generously oiled when running, enough to spatter all over the inner fender in just a few moments of running.

owen, thanks for the reply. i had forgotten about the oil drain holes, this engine has only been lightly used in the past 30 or so years.

would that failed check valve have any effect on my wiper performance? (there terrible) im having trouble seing what you mean by vacuum block. there is a hose that runs from the wiper motor to the lifter valley near the road draft tube. is this the one you mean for me to plug? how are the vacuum pump and intake manifold connected?

My car has the dual Rochesters, so I'm giving you this based on what I think the single carb model is like. The vacuum line from the intake manifold runs in a steel tube to the rear of the driver's side cylinder head, and there it is held down to a bolt in the head that also includes the body/engine ground strap and the steel vacuum line from the crankcase. From there both continue with rubber hoses up to a junction block on the cowl near the wiper motor. The block also connects via rubber hoses to the wiper motor and the washer head. Of the 2 vacuum sources, you'll have to grope around a bit to see which comes from the manifold and which from the crankcase. Temporarily plug the one from the crankcase with a bolt or similar.

The wipers should still give decent performance except under heavy throttle load with the crankcase pump disabled. If not, more than likely the wiper motor either needs internal lubrication (I use Mobil Vacuum Pump oil) or servicing. My crankcase vacuum line is intentionally closed off and my wipers are excellent under all conditions except full throttle when they slow down a bit.

Owen wrote:
"it doesn't have the valve spring baffles and the valve area is generously oiled when running, enough to spatter all over the inner fender in just a few moments of running."

Do the rocker arms have an oil squirt hole in them directly above the push rod????


MikeC. Owens advice about the drain back holes in the head is a good one and most likely the probelm u are haveing.

PackardV8 asks: Do the rocker arms have an oil squirt hole in them directly above the push rod????

I don't know, I checked the valve area oiling some years back before I realized that there were two different style of rockers, w/ and w/o those holes. And I don't think I've ever read in any of the STBs or SCs anything about that difference. Do you have any reference or information about them?

chances are i will be pulling the valve covers this evening. they were on my list already, because i figured the valves might need to be adjusted and checked for wear and things like that. Ill keep everyone posted with what i find.

Thank you, everyone!

Check out 55T-16. Are those the holes you refer to?

No, I don't think so. 55T-16 refers to holes in the shaft itself, while I believe PackardV8 was speaking of the holes in the rocker levers themselves.