Occasional smoke on start up.

[tony-muscle]

Well, here's the bad news. It still smokes a bit on start up and a puff on acceleration.
It's not the PCV tube, although I suppose I could pull the PCV and try again just to be sure, so I'm guessing the valve stem seals. As I said before, I'm not too worried about this right now, so if need be it will be a winter job. Damned annoying!

If it doesn't get worse I am sure you can live with it. If you turn off the engine and restart right away, does it smoke?

 

[Stanglover]

If it doesn't get worse I am sure you can live with it. If you turn off the engine and restart right away, does it smoke?

Not that I've seen. I have seen it smoke after sitting an hour or two.
Yes, for now, I'm keeping my eye on it. It is annoying, but not yet ridding the neighborhood of mosquitos, so I'll live with it.

 

[c9zx]

Good choice! Chuck

 

[timachone]

After reading the whole thread I would suggest to keep an eye on it but nothing more now. From what I know it is not uncommon that they could smoke a little bit through all their small gaps after some time. I would eventually go one step further and say it's quite normal on a piece of old iron. So if it doesn't get worse live with it and don't look back too often.

Just my 2 cents...

 

[Hemikiller]

Have you tried re-torquing the intake? Had plenty of Fords with oil consumption issues ending up being a loose intake.

 

[Stanglover]

Have you tried re-torquing the intake? Had plenty of Fords with oil consumption issues ending up being a loose intake.

I can try that for sure. Actually, today I plan on doing a "touch up" on the engine for the upcoming Retro-Fest Car show this weekend. That will be a good time to go over the bolts. Great tip there Hemikiller.

 

[timachone]

Yeah, +1!

I have installed my intake a few months ago again after a carb leak and some failed valley gaskets. I will retorque the bolts after the engine has had its first warm up to be safe!

 

[Stanglover]

Have you tried re-torquing the intake? Had plenty of Fords with oil consumption issues ending up being a loose intake.

I did just re-torque the intake and I was able to get a half turn on the 3/8" bolts @ 30 ft/lbs. Spec is 27-33 ft/lbs. The 5/16" bolts, I could only get a wrench on without pulling the carb, but I did manage to snug them up too. I know all were to spec when I installed the intake, so just goes to show they can and do loosen off. Talking of, the carb nuts took a good half turn as well.
Whether that will help stop the smoke, I have to wait and see, but I'm certainly leaning toward valve stem issues.
As said, I'm not sweating over it just yet.

 

[tony-muscle]

I did just re-torque the intake and I was able to get a half turn on the 3/8" bolts @ 30 ft/lbs. Spec is 27-33 ft/lbs. The 5/16" bolts, I could only get a wrench on without pulling the carb, but I did manage to snug them up too. I know all were to spec when I installed the intake, so just goes to show they can and do loosen off. Talking of, the carb nuts took a good half turn as well.
Whether that will help stop the smoke, I have to wait and see, but I'm certainly leaning toward valve stem issues.
As said, I'm not sweating over it just yet.

I don't know if they loosen up or is just the gasket creeping and compressing over time with the heat. Same deal with the valve covers and oil pan depending on the gasket materials.

 

[Stanglover]

I don't know if they loosen up or is just the gasket creeping and compressing over time with the heat. Same deal with the valve covers and oil pan depending on the gasket materials.

Could be a bit of both. Anywhere where gaskets are used, it is the one thing we all seem to overlock and that is to retighten nuts and bolts after a period of time.
Guilty as charged.

 

[71ProjectJunk]

That is just a very small bit of smoke at startup, and then it immediately clears, and that engine sounds very healthy. I honestly would not worry about it and enjoy the car. Check your oil consumption to see how much oil it is burning, but I would bet that it is negligible. I would certainly not tear the engine apart to try to get that small amount of blue smoke at startup taken care of. If and when you have time, just remove the valve covers and inspect the valve seals, if anything is obviously wrong then correct it, if not just forget about it and enjoy the car.

 

[DAverkamp]

I would add that a “little puff” at startup is NBD on a “well rode” horse that still runs and sounds great. That being said, I would also recommend you treat her easier on cold starts and let her get up to temp before whipping her in the butt a few times…

 

[Stanglover]

That is just a very small bit of smoke at startup, and then it immediately clears, and that engine sounds very healthy. I honestly would not worry about it and enjoy the car. Check your oil consumption to see how much oil it is burning, but I would bet that it is negligible. I would certainly not tear the engine apart to try to get that small amount of blue smoke at startup taken care of. If and when you have time, just remove the valve covers and inspect the valve seals, if anything is obviously wrong then correct it, if not just forget about it and enjoy the car.

You are absolutely right. I'm not going to rip it apart at this point, but it will be kept in mind. If I do anything, it will be over the winter, which winter, I don't know yet.
It's not the fact it blows a bit of smoke at start up, it's the comments I get from others (Chevy owners most of them) " do you know it's blowing smoke!!!" You know, Chevy owners knocking Fords.

 

[Stanglover]

I would add that a “little puff” at startup is NBD on a “well rode” horse that still runs and sounds great. That being said, I would also recommend you treat her easier on cold starts and let her get up to temp before whipping her in the butt a few times…

Actually, I did "whip her in the butt" a few times just for the video. I do keep the rpm's down until it warms up.
Thanks for the compliment on how she sounds. "Flowmaster FX mufflers"

 

[Stanglover]

Video update June 12 2022.
Yesterday, June 11th, I took the car out to Cars and Coffee at RM Restoration. So, after the car has sat for 24 hours, I wanted to check again for smoke on start up after I had retorqued all the intake manifold bolts.
I think the amount of smoke is a little less, but as said, the car had only sat for 24 hours.
Again I must stress, this is something I'm only keeping an eye on, not something that must be fixed now. The motor has not burned any amount of oil as of now and that's after a bit of hard running yesterday i.e. power shifting through the gear just for fun........... and make some noise!



EDIT: Who IS that old fart getting into MY car. I don't recognize him!!

 

[Sheriff41]

I'd hardly give that puff a second thought. Sounds good!

 

[Stanglover]

I'd hardly give that puff a second thought. Sounds good!

Thanks Sheriff41.
I'm 99.9% sure this is a valve seal or at worst, a bad guide issue. It will be looked at if and when it gets much worse.

 

[Rockin Ken]

In a previous post by Superbond, I mentioned that my engine had started to smoke on start up and I would post separately on my engine.
I don't intend this to be a long drawn out thread, but I would like to get an idea of why before I start spending money on pulling the heads and redoing them.......... again.
I know my way around my 71 M code 351C, but I have never done an engine rebuild myself other than replace head gaskets many years ago. The basics are fine.
Here's what I know. Last summer, I saw the first signs of blue smoke on start up and was told there was some signs of smoke on hard acceleration.
This year after winter's hibernation, there was noticeably more smoke. This only seems to be after the car has sat for a while and not so much after that.
What I know about this motor; It was redone in 2016 after an earlier build when the builder chose to put in a HV oil pump that eventually took out the #1 cam lobes and lifters as well as the main bearings. The latter build saw KB13cc dish top pistons instead of the KB flat top, a new Melling MTF 2 cam and the valve seals changed to a type with a spring like coil around the stem. Not sure what they are called! I do NOT know if the guides were done, but I do know the exhaust valves were change to SS one piece.
A couple of days ago, I did a cylinder pressure test and change the plugs back to Autolite 24's. I had been using Autolite 25's, one step hotter. This was to see if there was any significant change in plug color under the same engine conditions. Just me being curious I guess!
These are the numbers 1-8; 185, 190,195,195 190,195,192,195. # 1 cylinder also showed a slightly darker plug color, but no sign of oil. All other plugs were light brown with some variation. This is telling me that the rings are not the problem, so it has to be the valve stems or seals, but how do I know which without pulling the heads? Right now, I'm not overly worried, it's not belching smoke yet. If and when it gets to be worse, I'll have to consider a top end rebuild.
Oil; Castrol Edge 10W30, pressure; 70 psi hot running, 35-40 hot idle.
Thoughts?

the valve seals are leaking and or you may have bad piston oil rings or improperly installed oil rings

 

[Stanglover]

the valve seals are leaking and or you may have bad piston oil rings or improperly installed oil rings

Thanks Ken for your input. Please read post #37
This is so slight, I'm not too worried at this time. It doesn't smoke while running or anytime after start up. For sure, some oil is finding its way into a cylinder or two, but I'm not about to pull the motor apart (again) for this issue.......... yet.

 

[Tnfastbk]

Not to be a Smart a..... but are you sure its oil and not fuel causing the smoke?