Just Curious About Engine Oil Levels

[BLB27]

I have not yet driven my 1927 coupe. I had a slight oil seepage at the drain plug, so I drained the oil to install a new plug gasket. I thought it would be interesting to see how much oil would drain from above the lower spigot. I drained 2 quarts 16 ounces. There was 1 quart 8 ounces below the lower spigot. Therefore, the total drained was 3 quarts 24 ounces. I had put in a little over 4 quarts.

Once I start driving the coupe, I will keep the oil level at the upper spigot.

What would happen if the oil level dropped to the lower spigot?

[Erik Johnson]

Oil level can be anywhere between the upper and lower petcock. As long as it flows out of the lower petcock, you're fine.

It doesn't need to be at the upper petcock and shouldn't be above the upper petcock.

[TXGOAT2]

Ford recommended keeping the oil level about halfway between the upper and lower cocks. Check oil on level ground after the car has sat for at least a few minutes.

NEVER run the engine with the oil level below the lower cock.

Be sure the cocks are not plugged up.

There is nothing to be gained by running the oil at too high a level.

In most cases, all the oil will not drain out of the engine, so don't re-fill it with 4 quarts or it will probably be over-full.


Running the engine with too much oil in the crankcase invites excessive oil leakage, carbon deposition, and reduced performance.

Your engine will almost certainly leak some oil when in operation. Expect some oil drips after you have driven the car for several miles. this is generally considered normal. The car should not leave puddles of oil when parked, nor should it have oil all over the undercarriage after a drive.

Keeping the oil level about halfway between the nupper and lower cocks, as Ford recommended, will keep oil leakage and oil consumption to a minimum.

Check oil level frequently, especially with a new engine. Always check the oil level on level ground.

Don't use thick oil. Model Ts are designed to run on "light bodied" oil, which is about 20W. 10W30 works well under most conditions. In cold weather, 5W30 is fine.

I use full synthetic oil in my car with excellent results.

[TXGOAT2]

Expect your engine and transmission to make some mechanical noise. Do not add STP or similar substances, or use heavy weight oil in at attempt to make the engine run as quietly as a well-tuned Packard.

Do pay attention to engine sounds, and learn what a well-tuned and adjusted T engine ought to sound like.

[Art M]

I used to think more oil is better, so I kept the engine level way above the upper valve. My friends thought my engine needed a rebuild because it smoked so much when idling. Number 1 and 2 spark plug became fouled very quickly. Plugs 3 and 4 stayed clean. I don't know why the difference.

The oil level was reduced to the recommended level and the problem went away. My friends wondered how I was able to do an engine overhaul do quickly.

Art Mirtes

[TXGOAT2]

Ford stated to put 4 quarts of high quality oil in a NEW engine.

Since all of the oil will not drain out of the engine under ordinary circumstances, it will probably take about 3 quarts to refill the engine after an oil change.

Drain oil hot.

[Norman Kling]

When you change the oil, if you raise the front of the car, more oil will run out of the dips. But be sure to lower it to level ground when you pour in the new oil so the measurement will be accurate. I usually use one gallon of 10W30 oil. If synthetic costs more, it is not necessary because the T does not have a filter and all the sludge remains in the oil, so it should still be changed about every 500 miles. The purpose of synthetic is because it does not break down as soon and with a filter to filter out sludge a modern car can run about 5,000 miles on an oil change. So the standard oil will work just fine. When I change the oil, I pour in about 3/4 of the gallon of oil and then check the lower spigot. If it doesn't run out, I add more. Then I go to the top spigot and add till it just begins to drip. Use a stiff wire in the spigots when they are open, just to be sure they are not blocked. For additional oil, I use the same brand and weight of oil and add by the quart. Then when I go on a tour, I carry one or two extra quarts. With a good engine it will not need oil added often, but on an old worn engine it might need it after a days drive.
Norm

[BLB27]

The design of the Model T engine is amazing!! When the oil level is at the lower spigot, there is about 1 quart 16 ounces in it. I don't understand how this works.

The recommend level is half way between the spigots. How is this level determined?

[Mark Gregush]

Even raising the front of my T's higher then recommended by others to drain, I still never get a full 4 qts in them. I stop at about 3-1/2 to 3-3/4 and check the top petcock. If it runs out there, I let it drain off and call it good.

[TXGOAT2]

I've raised my front wheels 10" off the floor and let it drip all night, and still never got but just under 3 qts out of it. That's when running the oil level between the petcocks.

My car has an accessory dipstick, and I removed the upper petcock and used a bent piece of wire to gauge when the oil was halfway between the lower and upper cocks, then marked the dipstick at that point, and also at the level of the lower petcock.

[TXGOAT2]

You don't need to change clean oil. My engine is clean, and the oil stays clean for well over 1,000 miles. I do use an air filter, and I don't start the engine unless I'm going to drive the car for at least several miles. I have Kevlar bands, engine pans, and a screen and magnet in the transmission cover.

[speedytinc]

Oil seepage from the drain plug isnt always so.
Any minor leak from the crankcase ears goes to the drain plug.

[Humblej]

Bruce,
Don't overthink the oil level. Oil level needs to be between the upper and lower spigot...anywhere between. To achieve this level the oil should run out of the lower spigot and not run out of the upper spigot. So, if you change the oil and check the level by opening the upper spigot and oil runs out, you added too much, drain some off. You can do this by just opening the upper and lower spigots and allow some to drain, when the upper spigot stops running close the spigots.

[jiminbartow]

Here is an oil level chart and a diagram that will help you with the general positions of the control levers in order to attain certain speeds and conditions.

[BLB27]

Jim, Where is the lubricating system diagram from?

[DanTreace]

Jim, Where is the lubricating system diagram from?

From this 1920s MobilOil brochure made for T owners.

[BLB27]

Thanks Dan, Where could I get a copy of the pamphlet?

[BLB27]

Thanks Dan, Where could I get a copy of the pamphlet?

[DanTreace]

Thanks Dan, Where could I get a copy of the pamphlet?

Saw one on eBAY once. Don't know about reprints

But this webpage has a full color copy scan, got my screenshot from one being sold on eBay.

https://www.xr793.org/wp-content/upload ... ystems.pdf

[DHort]

When I change the oil I leave the upper petcock open. This lets excess oil drain. I usually only have to add 3 1/2 quarts. Then I leave the oil container on the floorboards to remind me that I have not closed the petcock. Sometimes I leave the oil cap there, too. I let it drain about 30-60 minutes and then close her up. I have 2 appliance trays under my cars filled with oil dri to soak up the oil that does drip.

[jiminbartow]

Dan. Thanks for answering Bruce’s question. My answer would have been, I found it online, but you gave the actual source. I was not aware that there was such a detailed brochure on lubricating the T. Thank you for sharing it. I wouldn’t mind having an original copy of that brochure myself. Jim Patrick

[John Codman]

If I drain my '27 warm for 15 minutes on a level floor, then refill the crankcase with four quarts of oil, the oil level will be exactly at the upper petcock. Being efficient (lazy), now I just put the four quarts in and don't bother to check the upper petcock.

[George House]

Consider running your T front wheels up on car ramps then drain the oil. You might get some sludge from the 3 or 4 dips of the pan bottom inspection cover. Then write ‘Chgd. Oil: date’ on a small piece of paper and scotch tape it to bottom of windshield/screen.