I Need Help Diagnosing My ‘25 Coupe…(Conclusion)

[MichaelPawelek]

I drove the 25 coupe about 10 miles yesterday and it ran fine. Parked it in the barn and went in this afternoon to start it up again for another drive. Hit the starter and after about a half a revolution of the engine everything just stopped. Tried it again and I could hear the starter engaging but the engine was not turning.

I thought it may be the Bendix so I took the Benfix cover off and spun the gears away from the ring gear and then went to the front of the car to turn the engine with the handcrank and in neutral. Nothing and it was dead stuck and would not turn.

I then took the inspection cover off of the transmission and at first look everything looks just fine. Could push the car back and forth slightly in neutral and see the individual planetary gears spin. Then put the hand lever into high gear and rocking the car back-and-forth could see the planetary gears stationary but moving with the fly wheel.

At this point with the hand brake lever in the neutral position I can push the car backwards and forwards as much as I want but once I put it into high I get to a certain place and everything stops dead so at first I still thought it must be the transmission. But at this point I can put the hand lever back into neutral and turning the handcrank in front get to the same position every time and can crank the engine no further. I took the inspection plate off the bottom of the engine and at first glance everything looks just fine and whenever I move the car in high gear laying under the car and pushing a wheel it always blinds and stops with the number two and three pistons at their upper travel. Since the engine stops hand cranking and will not spin even with the car in neutral at a certain point in its rotation I am guessing it is something in the engine because at that point it is no longer connected to the transmission.

Tomorrow morning I will take the spark plugs out and I’m wondering if I can rotate the crankshaft with gloved hands and the transmission in neutral to determine whether this is actually in the engine or in the transmission. Any thoughts please?

(Conclusion in my last post)

[TXGOAT2]

You may have a head gasket leak. If the car ran fine the last time you ran it, with no significant knocks, I would suspect that the head gasket has leaked enough coolant into one or more cylinders to prevent the engine turning past a certain point. You can readily determine this by removing the spark plugs. I would take them out and keep them in order. If you find evidence of coolant in the cylinder(s), it's most probably due to gasket failure. Some coolant will probably leak down into the crankcase overnight, perhaps even enough to allow the engine to crank. I would not use the starter to crank the engine, since there is some danger of bending a rod or doing damage to a piston if the engine locks against liquid in the cylinder(s). Either use the hand crank or put the car in high and push or rock it to move the engine after you remove the plugs. Other things could cause this, like a broken valve, but I'd look for evidence of a gasket leak first. Some long shots include timing gear issues, a magneto or transmission issue, cam problem, seized piston, and more, but, again, I'd begin by looking for coolant in one or more cylinders.

[TXGOAT2]

PS: I would use the hand crank only to move the engine. If you want to turn the engine backward, put the car in high and push it backwards. Reaching into the crankcase to turn the engine can lead to painful injury if the engine moves unexpectedly and catches your fingers or other appendages in the mechanism.

[MichaelPawelek]

Will give it a look first thing in the morning. Since I drained the oil and took the engine inspection cover off with a fresh piece of cardboard now under the engine I might see some evidence before I take the spark plugs out. I sure hope it’s this simple and I don’t have to take the engine and transmission out but if I eventually have to I will…..

[MichaelPawelek]

Ok, A good update! Could not stand waiting until the morning so I took the plugs out and all cylinders dry. I then tried rocking the car in high gear with the plugs out and it rolled 10 feet forward and back with no problems. Can hand crank the engine now with spark plugs out and installed! Can I assume I had a valve stuck closed that now is working? That might account for the engine stopping in the same place every time?

Wondering if I am getting carbon build up from the engine running so cool. Yesterday after the 10 mile drive with temps. in the low 80’s F both a meat thermometer in the radiator neck and infrared thermometer at the top of the radiator showed 170F. I have the new longer water pipe and smaller fan belt on order so I can remove the water pump when the parts arrive.

[Norman Kling]

One thing I noticed as you posted what you did. The starter turns the engine forward when it is working. If it jams, the engine will not move forward because of the spiral threads on the starter bendix shaft. However if you put the car in high gear and push it backward, it will push the gear away from the flywheel. When the starter is unlocked from the flywheel, the engine should turn with the hand crank. If this is the case, the flywheel ring gear is worn out. Since the engine almost always stops in one of two places the gear at those places is worn out but in between the teeth are usually still good. So before you use the starter, turn the hand crank about 1/4 turn. Then the starter should usually work. Always turn 1/4 turn with the crank before you use the starter until such time as you remove the engine and install a new gear on the flywheel. The starter bendix gear might also be worn and if so should also be replaced.
As posted above, the problem could also be caused by a stuck valve, but unlikely to stick if the engine was recently run.
Norm

[Wayne Sheldon]

Proceed with caution. Years ago, I helped a fellow who's car was running fine, and then after being shut off stopped solid at one spot. Pushing the car forward and backward, that spot was close to the same spot in both directions. Turned out, a 3/8-24 bolt about an inch long had been left inside the engine by some unknown past worker? (Probably the owner, but he didn't admit to it!) It had shaken out of its hiding place and was picked up by a flywheel magnet. When he went to crank it, the bolt hit a very slight dent (it could have been anything else, but the dent was just the right amount) near the bottom of the pan. The bolt would hit that same dent, but from either side of the rotation. We found and fished the bolt out after removing the starter.
He was VERY lucky! The bolt could have shaken down and been picked up while the engine was still running! Or had the small dent not been there, it might have been picked up and stayed until the engine was started later. Or he could have jiggled things around just right and gotten it to pass by the dent, and then started the engine. Any way, it could have gotten to speed and then locked between the flywheel and hogshead or pan or field coil and totally destroyed the engine! I have seen a couple model T engines exploded by hardware wandering loose in the pan. Not a pretty sight. Photos of several such engines have been posted on the forum in the past.

An important question. Was the stopping of the turning sudden and mechanical feeling? Or somewhat softer? Did it go "CLUNK"? Or squeak? Or maybe a soft "thud"? Hydro-locking is usually a softer stoppage than say even a stuck valve. At this point, I would not fully expect it to be hydro-locked because wetness inside the cylinder should remain for awhile (ninety percent of the water could drain out in a matter of hours if the conditions are right?). Maybe take a clean dry small piece of paper towel, looped into a foot of fine wire, and wipe around inside the cylinder a bit. Pull it out to see if any water remains? (I use that trick often!) Just to be sure.
I also would not expect it to have been a stuck valve, although that is possible. Valves usually won't stick hard enough to stop the cranking unless it has been a few weeks since the engine ran, and even then there usually has to have been some sort of catalyst, water in the oil or something? I have seen one stick hard overnight. But that doesn't happen often. The one I saw had a very fresh and somewhat too tight engine. (I keep telling people that a tiny bit TOO tight is worse than just a little bit loose!)

[MichaelPawelek]

Norman, I understand what you are describing but the very first thing I did in this process was to take the cover off the Bendix and physically spin the gears away from the flywheel. All the times afterwards when I pushed the Model T forward and back, and then tried the hand crank multiple times the Bendix gears were never in contact with the ring gear yet the engine always “froze” at the exact same place in piston position.

[MichaelPawelek]

Wayne, Now that the engine is freed up, see my post above, I will try my best to feel into the drain plug and look into the transmission and engine area as well as possible since I have the cover off the hogshead and inspection plate off the bottom of the engine.

PS-Besides having learning disabilities from childhood, my eyes operated on 6 times and severe hearing loss as a adult I have no idea what kind of sound the engine made when it initially stopped. Like my rebuilds I rarely run on all cylinders at the same time.

[TXGOAT2]

It might be possible to "fish" in the lower part of the transmission and the engine sump for small loose metal items by attaching a small, strong magnet to a length of rubber fuel line. The magnet would need to be very firmly attached and the assembly would have to be free of any projections that could catch on anything. An electromagnet would be ideal, but you'd have to make your own.

[TXGOAT2]

Carbon is a possibility, but unlikely. A stuck valve, likewise. If you can obtain a borescope, it would be worth having a look for any evidence of heavy carbon, or a scored cylinder. The boresope might allow taking a better look around the crankcase and transmission innards for any sign of loose or missing parts. If your engine has cast iron valve heads, they've been known to break apart and cause problems.

[MichaelPawelek]

I looked as best I could this morning into the transmission while pushing the T and watching triple gears go round and up into the lower end of the engine and saw nothing odd. I wish Henry had not installed the tiny plate above the oil drain hole so that area could be inspected.

Buttoned everything up and added fresh oil and started the engine. Everything ran smoothly and I dove down the road a bit and back into the barn. Checking under the T for oil leaks I decided I needed to advance the spark a bit. Good thing I had the floor boards out. As I advanced the spark the increased engine speed was enough for a small piece of metal sounding object to come loose off a magnet and hit the side of the hogs head. The engine still ran fine afterwards and I now know I have a ticking time bomb somewhere inside. Looks as if the engine and transmission need to come out…..

[Scott_Conger]

Michael

FWIW...it was already loose...that's what locked you up in the first place. Hopefully damage is minimal, but you have a fair amount (read: "a lot") of work ahead of you

[speedytinc]

There is a pesky area between the back of the flywheel & the pan. Big enough for a washer or nut to stick.
A bit of the area can be seen thru the drain hole. Can view magnet ends & pick with a wire. A bore scope would make the job real easy.
Feeding a T shirt into that hidden area might move it enough to ear spot it. Dont ask my how I know this.
"fishing" post a few months back. HH removal not needed. Good luck & Patience.

[TXGOAT2]

The baffle above the oil drain is probably intended to provide a place for bits of carbon and metal to settle where the agitation from the flywheel could not pick them up and recirculate them. You might try taking your starter off and looking for evidence of something stuck to the magnets or any indication of impact damage. It might also allow fishing with a magnet for anything loose down in the sump area. I would also consider removing the hogshead and looking carefully for any missing parts. Even a small cotter pin or piece of safety wire could jam the engine if it landed in the transmission gears or timing gears. Removing the generator would allow some access to the cam gear for inspection.

[TXGOAT2]

Re: "Feeding a T shirt into that hidden area might move it enough to ear spot it. Dont ask my how I know this.
"fishing" post a few months back. HH removal not needed. Good luck & Patience"...... That's a great idea. A length of soft nylon or cotton rope about 3/4" OD might also work. Feed it in while a helper slowly moves the engine with the crank. Don't force it. Back the engine while pulling gently to remove it. Pulling small wads of cloth firmly attached to wire or crate strapping around the transmission drums might get results...

[Norman Kling]

Here are a couple things which have happened to me in times past.
1. One of the bolts which hold the driven plate to the back of the brake drum came out. Even though it was wired together with the other bolts. The threaded area inside the drum had cracked and the bolt came out. It fell into the crankcase and made a big bang. I was about 40 miles from home when that happened. It was still running so I continued home. Next time I tried to use the starter, it wouldn't work because the bolt had caused some teeth to break off the ring gear. I took off the inspection plate and found the bolt laying on top of the filter screen!
That engine came out and I was preparing to replace the ring gear and do some rebuilding, when I came across a rebuilt engine and transmission in a swap meet, so I bought them and installed into my car. The first time I drove it after installing, the magneto quit after going about half a mile. This time the funnel had been too close to the magnets and broke off. It didn't make any noise and I didn't know what had happened for about 10 years later, I had been driving on battery all those years. The funnel had been laying in the bottom of the crankcase. When it came off it cut the winding on the magneto ring.
Another thing which can come off is a keeper on the outer end of the magnets. If you remove the starter, and rotate the engine you might be able to see if it is missing through the starter hole in the hogs head.
Norm

[MichaelPawelek]

Thank you for all the reply’s and help. A few minutes ago I took another look at the transmission screen after the run this morning and found a mangled piece of brass screw head so chances are a magnet keeper is amiss.
Anyway engine and transmission are coming out starting next week……

[TXGOAT2]

Sounds like you have your culprit. If the engine is otherwise OK, I'd make an effort to recover the item before taking everything apart. If the engine needs a going over, now is a good time. Depsite catastrophic Global Warming, Winter seems to be well on its way....

[MichaelPawelek]

Well, I’ve done this 3 times back on other Model T’s and my Model A but I was a lot younger and did not have lower back problems. I might farm this out to Ross Liliker in College Station. In the mean time I am fortunate to have other toys to play with that always need care…..

[John Codman]

Love that Isetta. The Messererschmidt isn't bad either!

[TXGOAT2]

OMG, Invasion of the Bubblecars!!!

[DickC]

I guess you have found the problem and won't be fishing in the pan for some metal. If you ever need to go fishing however, I have used a magnet strip from the inside of older refrigerator gaskets. It is about 4 to 5 feet long and easily slides down the transmission door along the bottom of the pan. It picks up all the missing metal and holds it while withdrawing through the transmission cover.

[MichaelPawelek]

Wow, That is a great idea!

[MichaelPawelek]

Due to time constraints, my age and awful lower back problems I last week decided to let someone else take the engine and transmission out of my ‘25 Coupe to find out what had come loose.

Sure enough the culprit was a magnet keeper that had come loose but since I turned the engine off right when I heard the metal hit the inside of the hogshead no other damage was done. Oddly enough whom ever rebuilt this engine some 20 years ago did NOT peen the ends of the brass magnet screws…..