I flushed out the radiator (still on the car) and after doing so I planned on going for a short ride. I got Henry started and let him sit outside for a minute while I put the tools away. When I got back I noticed smoke coming out of the hole in the valve cover and the oil filler spot. it wasn't a lot of smoke, but enough that I stopped the car and put him back in the shop.
Am I burning oil? Will I need to replace the piston rings?
Luke-first,how does it run otherwise? If it runs OK and does not knock excessively l would leave it alone. This is common. They vent this way. All cars when worn a little smoked like this pre pvc valve.
It's an old Model T - what do you expect
Of course it's burning oil, and that's not enough - it'll leak too. If it doesn't leak you should be worried - maybe it haven't got enough oil?
As long as it runs good and doesn't keep on fouling the plugs with burned oil, then you shouldn't be too worried.
Rebored with alu pistons and modern rings it shouldn't smoke much through the valve cover hole, but that expensive work shouldn't be necessary until you have really bad compression that can't be helped with a valve job.
(Message edited by Roger K on August 08, 2016)
Also, l can't post it, but in one of Floyd Clymers books there is a cartoon. A couple are riding in their closed T. The man says I KNOW you smell smoke! There IS smoke!
Bit of blow-by as it's called. If you really want to check it out do a dry then wet compression test. I'm assuming your comp will go up slightly on the wet test because you have leakage around the rings causing a bit of pressure in the crank case and the mist is escaping from the only places it can. The oil fill cap and the valve cover hole for the fuel rod.
Thanks to all. I knew the model T wouldn't run "clean" or super efficient, but I didn't want something to be wrong and me do nothing about it.
Thanks again for the help, luke
I agree with Charlie, it's piston ring blow by which is to a degree pressurising the crankcase and venting out of the valve cover and most likely the filler cap too. Keep driving it and enjoy. If it's a new engine the rings will bed in and the smoke will reduce OR an old engine it will get worse eventually!
No one has asked yet, what grade of oil are you using?
Re Jim's post above. From Henry's Wonderful Model T.
I am using 30W oil.
Thanks, Tom, for putting that on. I have in my memory bank some amusing episodes of things that happened when taking lady friends for rides in my old Fords.
"I flushed out the radiator (still on the car) and after doing so I planned on going for a short ride."
Did you refill the cooling system after this?
Are you sure what you are seeing is smoke and not steam? Does it smell like burning oil (smoke) or no smell (steam)?
You said you flushed the radiator - did you use a chemical? It's possible that you dislodged some rust that had been sealing a hole or crack in the water jacket near the valve cover. Maybe some water got into the crankcase?
Not too long ago, I took a ride in a Hupmobile sedan. The owner complained of a lot of smoke under the hood that was also coming into the cabin. Sure enough, as we were driving the cabin filled up with "smoke." Actually, it wasn't smoke, it was steam due to a cracked block or head.
Ken, yes I did refill the cooling system.
Erik, it is possible that its steam not smoke. I didn't smell it though. No I did not use a chemical, just water.
Thanks again, luke
It comes from two sources. around the valve stems and guides and around the piston rings. Caused by the combustion gasses leaking through. It builds up pressure and the only places where it can come out is that hole or the oil filler cap.
If you lose a lot of power, or burn excessive oil, or excessive smoke gets in the passenger compartment you will need to rebuild the engine. If just a little bit of smoke, just keep driving. Eventually something big will require pulling the engine and transmission. That is the time to go through everything and rebuild.