[supersport#69]

My car sat for about a year. After starting it for the first time it smokes now. I’ve changed the oil after running some mmo in the engine and fuel a bit. I added a can of sea foam in tank the other day and I’ve only got maybe 20 minutes run time on it.
The problem is it’s in limbo right now waiting to go back to paint so I have the taillights and rear bumper off. All I’ve done is drive it down my street a few times and let it idle in my garage.

What I notice is when I start it there’s no smoke and after 5 min or so there is and I can smell oil. Is this a result of sitting too long and needs to just be driven or am I going to be looking at a valve job?
There’s 68k about original miles and it don’t smoke before it sat.

[FrankieT/A]

What you are describing is rings...

["QUICK-SILVER"]

If it's an automatic car, check for a leaky modulator valve. Hose going up to carb/intake may be sucking transmission fluid and making it smoke.

Clay

[supersport#69]

It’s a 4 speed.

The problem seems to be random. A bit ago I ran it and it didn’t smoke at all for the 15 minutes I ran it but I didn’t drive it. It just idled.

Can it be rings if it’s hit and miss? I guess I won’t know for sure until I can drive it around consistently for a month or so.

[supersport#69]

I think I’m going to put some trailer lights on the tail panel so I have stop lights and take it on some long drives. If it doesn’t work itself out completely then I guess it’ll be stem seals or rings. I hope it’s not rings though. That will be a setback for me.

[Ben M.]

Rings or valve guides. My engine did the same thing and it was bad valve guide seals (teflon seals from 20+ years ago).

[dataway]

I think the old adage is .... smoke on acceleration is rings, smoke on deceleration is guides/seals.

But first I'd want to make nice steady highway run to burn out any oil that has accumulated while sitting for a year ... which is usually from guides/seals leaking into the cylinders, soaking the carbon, maybe dripping into the exhaust manifolds etc. Then assess the situation from there.

[FrankieT/A]

Originally Posted by dataway

I think the old adage is .... smoke on acceleration is rings, smoke on deceleration is guides/seals.

Yes, I agree but long idle like waiting for a red light then accelerating is rings and since the car has sat can put it in the ring category.

[supersport#69]

The last time I drove it was 8 days ago and it was just around the block a few times. It didn’t smoke when started but after it dropped to low idle and I back out it started smoking. It smoked when I pulled out and started driving. By the time I came back to my house it had already quit smoking and I let it idle a bit more.

The motor was recently pulled to replace the pan and rear seal gaskets. I wonder if some grease or sediment got into the cylinders when it was flipped down getting old gasket scraped off the block.

I plan to get some lights on it today and take a drive but it is really Smokey where I am. Near the foothills of Sierra Nevada and fires everywhere right now.

["QUICK-SILVER"]

Originally Posted by supersport#69

The last time I drove it was 8 days ago and it was just around the block a few times. It didn’t smoke when started but after it dropped to low idle and I back out it started smoking. It smoked when I pulled out and started driving. By the time I came back to my house it had already quit smoking and I let it idle a bit more.

The motor was recently pulled to replace the pan and rear seal gaskets. I wonder if some grease or sediment got into the cylinders when it was flipped down getting old gasket scraped off the block.

I plan to get some lights on it today and take a drive but it is really Smokey where I am. Near the foothills of Sierra Nevada and fires everywhere right now.

Oil smoke after being upside down doesn't count. Oil could seep behind compression rings and got under shields on valve springs.

A little drive time should cure it all.

Clay

[supersport#69]

Thank you. That at least gives me some hope.

[dataway]

Yep ... oil gets into all kinds of weird places with the engine upside down. Will probably find it's way past the rings, into the combustion chamber, then onto the valves, into the intake, could take a while to suck all that residue back into the cylinders and burn it.

[supersport#69]

Started it up and it idled not smoking for about 4 minutes. Then it started to smoke but tapered off after a couple of miles. At a stoplight idling it smoked until we took off. Then I got on the freeway and cruised a strip of road about 50 miles and it didn’t smoke at all.

I Drove home after the freeway and it didn’t smoke at all or pulling in the garage or idling.

I feel hopeful for sure now.

Could I eliminate rings at this point or still possible. I tried to replay what I did in order not trying to put anyone to sleep. Lol

[dataway]

Sounds like it's just burning out oil residue. Pretty sure bad rings would smoke immediately on startup as the engine is cold and the clearances larger. It was just waiting to get hot enough to burn out the oil. It can soak into the carbon and the valves and combustion chamber and take a while to clear out. Honestly, if I had an engine upside down for any length of time I would expect a LOT of smoke for a while

[supersport#69]

It may have been upside for 2-3 days on that stand as I it took about 12 days for the mail to deliver my gaskets. It sat idle. I wasn’t even thinking about that possible issue.
My carb is even acting odd now. I don’t know if it’s primer dust or something else but when I start it the high idle is way too high like 2500 rpm high. Or more. It was so loud I took the lid off and started opening the flap and tried to kick it down sooner. It could be the electric choke is malfunctioning. The carb is original and been rebuilt but a year sitting who knows.

[dataway]

I'm no Q-jet expert ... but I know a lot of their mechanisms work based on gravity ... floats, needles hanging on hangers, weighted sections of linkage ... possible something didn't like being upside down and needs to be jiggled back in place ... I'm assuming the carb was still attached while it was upside down .... if not, never mind

[supersport#69]

It was off the motor. We pulled it to mount the plate for the cherry picker.

I’m going to try to drive it today and hopefully work more cobwebs out.

[68gtoMN]

I'm pleased to read that this issue appears to have abated. Another simple test for blow-by (rings) is to remove the oil fill cap or air cleaner vent tube from valve cover and feel for pulses of air blowing back at your hand through crank case. This signals air rushing past piston rings into crank case and out through valve cover.

[supersport#69]

Well I guess I’m not out of the woods now. I thought no smoking was good now this.

I took it to a mechanic friend and it’s missing. I didn’t even know it was. The second cylinder from front passenger side. He checked compression and it was 75 at first movement then dropped to 35 lbs. the cylinder in front passenger was 150. The plug in the low cylinder looked like new when removed with fresh gas on it.

So tomorrow pulling the valve cover to see what’s going on. He’s thinking it’s valve related, possible bent push rod or flat cam or if I’m
lucky a rocker issue.

So I’ll know more tomorrow.

[supersport#69]

Aside from timing chain replaced I don’t think it’s ever been rebuilt. I guess it’s possible the original owner could have swapped cam when chain was done but I don’t know.

The car did sit a year and I didn’t drain the tank, just added fresh so maybe caused a sticky valve? Could a lifter be flat?