Engine Knock.. egad!!

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Model T Ford Forum: Forum 2018: Engine Knock.. egad!!
Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Monday, July 30, 2018 - 03:32 pm:

Ladies and gentlemen I need help on how to proceed in locating and fixing the source of an engine knock my 15 touring has developed. I have not had the car long but it has been in the family a long time and sat for too many years. I believe this to be a recent development. The car starts easily and seems to run just fine except for this noise. Noises worry me.
What I have done so far.
1) oil level is OK and oil is recently changed to 10w-30 Mobil one. From?? but knowing my dad probably a 30w non detergent
2) Grounded plugs one by one and noise persists
3) Grounded 2 and 3 together and still there
4) I describe the sound as if someone is taking a large hammer and lightly tapping the block. More of a light thud than a rattle or ping.
5) Using a stethescope I poked around the engine bay and the noise seemed most prominent in a couple of places and can actually be felt through my fingers holding the stethescope. a)the water pump housing (disconnected it and the sound remains), b) I have a three dip pan and it was most prominent on the 2nd and 3rd dip and to a lesser extent on the 4th molded into the case (14 bolt cover). Did not really hear it well on 1.
4) Is related to engine speed. Most prominent at idle but this may just be it is drowned out some by all the other vibrations/noise at higher RPM.
5) Noise not affected by position of spark. (Fresh gas, Non alcohol with Stabil in it).
6) Car restored and engine rebuilt about 40 years ago but not a lot of mile since then; a few tours; but none recent.
7) I know nothing about the last rebuild (shims, what was done, type of crank, etc)

From the other threads I have perused My thought is the main bearing between 2 and 3; if so; Can a guy with average mechanical skills but little hands on "T" experience fix this? I have a Ford book but this assumes a lot of existing experience on the part of the mechanic that I do not possess when it come to Model T's. Can this be fixed with the engine in the car?

Any T guys in Naples Florida who could listen to the noise and help with diagnosis and how to proceed from there?

I think I could do it with a well written step by step guide but............

I really want to bring this car to the Cookeville tour next August. Lets get it fixed up and ready to go problem free

Thank you all in advance for your help and wisdom in such matters
Garland


Top of pagePrevious messageNext messageBottom of page Link to this message  By Scott Conger - Wyoming on Monday, July 30, 2018 - 03:47 pm:

PM sent


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Monday, July 30, 2018 - 04:40 pm:

Get the MTFCA engine manual. It could also be the crankshaft fan pulley or the camshaft bumping the front cover.

You can fix it yourself if you are not all thumbs.

These cars have been owner maintained since the beginning.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Monday, July 30, 2018 - 04:46 pm:

Thanks Ted,
I had just finished ordering all the manuals when I saw your note.
Garland


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Monday, July 30, 2018 - 04:58 pm:

Hopefully, you can find someone locally with experience who can help you. What you describe sounds to me like a main bearing. If it is the center main, it might be better not to try to tighten it because the usual cause is worn 4th main at the rear of the transmission which allows the transmission to sag in back and put an upward pressure on the center main. Therefore, if you tighten the cap on that main you will force the crankshaft up in the center and as it moves will cause metal fatigue leading to broken crankshaft. If it is the center main, the best fix would be to pull the engine and check the alignment of the bores in the block. Re-pour the mains if this is the cause and replace or re-babbit the 4th main at the back of the transmission.
If the engine has overheated, you could also have collapsed pistons. That is they expanded with the heat and when they cooled off they are too loose in the bore. Only cure for this would be new pistons.
Anyway, before you take anything completely apart, find someone locally who can listen to your car and diagnose the problem.
Many knocks at idle can be caused by something as simple as a loose pin in the front of the crankshaft. This is the pin which the crank turns when you crank the car. It moves from one side to the other at idle, but when your engine is moving faster it stays in one position and the knock stops. Others can be the camshaft bearings loose in the block or worn where the cam rotates. too loose in the bearing. Even loose timing gear can cause a knock.
Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Monday, July 30, 2018 - 05:08 pm:

It's not likely to cause the sound you describe, but it's a possibility that's easy to check: see if your crank pulley is loose.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Monday, July 30, 2018 - 05:22 pm:

Thanks for the ideas. Want to check the simple stuff first.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Monday, July 30, 2018 - 05:30 pm:

Norman,
The engine has not overheated to my knowledge.


Top of pagePrevious messageNext messageBottom of page Link to this message  By James A. Golden on Monday, July 30, 2018 - 05:49 pm:

I removed a T engine today with a knock.

The owner thought it was the transmission.

Everything looked good in the drums, no excessive wear showing.

The triple gears were actually rubbing on the flywheel and the bushings were a little loose.

Some of the coil ring pole pieces and magnet pole pieces have marks on them like they were rubbing each other.

I have the tool to check the magnet pole pieces in height and the Mag coil ring to ensure it is correctly set, but that will wait another day or so.

I also have a tool to measure the magnetic strength on the magnet pole pieces.

A reading of 425 to 475 ensures a T engine will start on Mag with a good clearance for those pole pieces.

I measure the center area of each side of the brass screw that holds the pole piece in place.

The reading were wild there today.

I would have over 400 on a North set and 3 or 4 on the adjacent South sets.

Some would read real high or normal and some lower than I ever measured before.

This was just a random quick check, but I doubt the engine ran on Mag.

Next time I will chart all the values to see if there is any kind of a pattern and then try charging the magnets for another test sample.

All the magnets were clean and appear to be crack free.

I have heard that banging or dropping a magnet will take out the magnetic fields, but I am wondering if the pole pieces hitting could also take out the magnetism.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chris Landry, Hudson, NH on Monday, July 30, 2018 - 09:50 pm:

Remove the pan and see if the connecting rod big ends are loose. You shouldn't be able to easily slide them back and forth on the crank boss. I had that issue and was able to temporarily calm down the knocking by adjusting the rod bearings but, in reality, the babbit was bad and the rods eventually had to be replaced with rebuilt ones.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Monday, July 30, 2018 - 10:13 pm:

I believe any sudden impact can reduce magnetism, and I think that would include magnets hitting the field poles. That's why I adjust magnet height with brass shims rather than whacking the magnets down with a hammer if they're high.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John V. Dow on Monday, July 30, 2018 - 10:36 pm:

My T rattles due to slop in the aluminum cam gear mating surface with the crank and generator gears. I placed an extra, thicker gasket on the generator mounting flange it moved the contact surface enough to change "meshing" location to a less worn spot. The rattle stopped but reappeared as the gear became worn-in as before. I suppose a nylon gear would eliminate the problem. Model Ts rattle--I ignore it.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Neil Kaminar on Tuesday, July 31, 2018 - 07:25 am:

Garland,

It does not sound like a loose bearing to me but I could be wrong. There could be a number of things wrong as others have described. Norman has the best advice. With an old restoration and a "lot of miles" on the engine, it is probably time to take it out of the car, take it apart, do a careful inspection, and fix whatever is wrong. This would be the wise move. You can start taking things apart with the engine in the car but in the long run it is less work to fix things with the engine on an engine stand. While you are at it you can do some upgrades like a new camshaft.

Neil


Top of pagePrevious messageNext messageBottom of page Link to this message  By Neil Kaminar on Tuesday, July 31, 2018 - 07:38 am:

Sorry, misread your post. You said "NOT a lot of miles."

With an unknown rebuild it still might be wise to take the engine out of the car.

One thing that happens with an engine with babbit bearings is that they seat in after a few hundred miles and have to be taken up. It is quite common for the bearings to develop a knock after a rebuild and a few hundred miles, especially if they were seated by scraping. So you might want to check the rod bearings first before taking the engine out of the car. Take one shim out at a time, alternating sides, until you cannot crank the engine over by hand, then put one shim back. Torque is 45 foot-pounds. Make sure the bolts are good. If in doubt, replace. You can use self locking nuts, discussed elsewhere on the form. Make sure you have oil on the bearings when you re assemble them. Mike Bender has some good videos about rod bearings. If this doesn't work, then do the same with the main bearings. Check all the other things too as suggested by others.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Tuesday, July 31, 2018 - 08:33 am:

Thanks all. Lots of things to check. Will start by dropping pan and having a look-see to check for play in rods I think. Sounds heavier than just a rattle to me. What do I look for to tell if the babbitt is bad?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Bob Shirley on Tuesday, July 31, 2018 - 09:26 am:

Heads up, remember the troughs in the inspection plate are full of oil. You may want to protect the floor.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Val Soupios on Tuesday, July 31, 2018 - 10:41 am:

Jack the front end up as much as possible to drain the oil back into the sump. Let it sit that way for a bit and almost all the oil will drain out of the troughs. Leave the front jacked up and make sure it is secure when working under the car.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Tuesday, July 31, 2018 - 10:58 am:

Thanks for the oil shower warning. I have a good jack and jack stands so will do. Might make it easier for "a man my size" to work on it under there too!!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Neil Kaminar on Tuesday, July 31, 2018 - 04:30 pm:

Another option is to just drive it up on those ramps that go under the wheels. I see them at garage sales all the time.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Wednesday, August 01, 2018 - 01:49 pm:

Note to self. Be sure the overhead door is closed before you jack up the car. Just about jacked the roof bow into it. Not much clearance. Put the top down.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Wednesday, August 01, 2018 - 05:15 pm:

Thanks Norman for leading me in the direction of the pin the crank engages. It is not loose but would have failed eventually as it is only in one hole of crank pulley. Pin is not long enough to reach hole on opposite side of pulley and is just jammed up against the inside of the pulley. In there tight so I'm not sure this is causing the noise as have not restarted the car but would have left me in the lurch on a car without a starter eventually.
Thanks again
Garland


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Wednesday, August 01, 2018 - 06:34 pm:

Can the crankshaft pin be removed while the engine is in the car? Mine does not look like the one in Snyder's. It appears to be threaded???? Will try to send a picture.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Val Soupios on Wednesday, August 01, 2018 - 09:35 pm:

If it is the correct pin it can be done but it is a lot easier with the radiator removed.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Craig Anderson, central Wisconsin on Thursday, August 02, 2018 - 01:49 am:

The '20 Coupe I had had an intermittent "knock".
Turned out to be the spring on the hand crank was broken.


Top of pagePrevious messageNext messageBottom of page Link to this message  By James A. Golden on Thursday, August 02, 2018 - 07:15 pm:

You will note that one pulley hole is larger than the other one and there is a hole in the oil pan snout right below the crank pulley.

There is normally a Cotter pin in the crank pulley pin on the big hole side.

Remove that Cotter pin and with the small hole right on top, then that pin can normally easily be driven out the bottom.

Some times the pin will wear and easily slide back and forth to produce a ringing noise.

If that is the case, remove the pin, heat it in the center area and flatten it just enough sot it will have to be tapped in place and will stay put there.

Other more drastic methods might be considered to stabilize the pin.

Replace the Cotter pin anyway.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Neil Kaminar on Thursday, August 02, 2018 - 08:25 pm:

I had a "knock" when turning right. Turns out the fan was hitting the hand crank when the hand crank was slung to the left by the right hand turn. Or was it left hand turn. I forget.

Anyway, I fixed it by getting a longer fan belt.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Friday, August 03, 2018 - 08:54 am:

James. Thanks I had not noticed the difference in the size of the holes. Is this why the pin doesn't extend into the hole on both sides of the pulley? Either way mine does not have a cotter pin in it and will add this for safety. Pin seems very tight so don't think it will go anywhere. My pin looks like it has threads on it but may just be knurling to keep it tight. Don't think now this is the source of my knock. Will probably open up inspection pan this weekend to check rods.

Someone else brought up timing gear as possible source of noise. Is there a way to test this theory without removing front cover. Radiator is off so now is a good time to look at this too!!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Val Soupios on Friday, August 03, 2018 - 09:45 am:

Garland, that pin has to go through the holes on both sides so you can fully engage with the crank. The split pin is there to keep it from backing out through the large hole. Get a new pin and change it now while the radiator is off. The pin goes in with the hole for the split pin closest to the insertion hole in the pulley. I have seen lots of cars where the pin was put in the other way and that allows the pin to back out. Hope my description was clear enough.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Friday, August 03, 2018 - 10:08 am:

Val. I think I got it. Will change it


Top of pagePrevious messageNext messageBottom of page Link to this message  By Harold Schwendeman - Sumner,WA on Friday, August 03, 2018 - 04:28 pm:

Garland - To check for loose timing gear, remove the oil fill/breather cap and with a good trouble light, you can see the top of the timing gear. With something like a screwdriver (brass rod or wood dowel rod would be better) you can pry on the gear and if loose enough, you can usually detect movement. If so, it will then be necessary to remove the timing gear cover to tighten the nut which secures the gear to the end of the camshaft. Hope this is the problem for you as it would be a rather easy "fix"! FWIW,.....harold


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Friday, August 03, 2018 - 07:41 pm:

Thanks Harold. Didn't want to take off the cover unless I had to. This is what I love so about this forum. Someone knows the easy way to check something and I don't have to figure it out the hard way
Looks like a busy weekend ahead. Supposed to rain anyways
Garland


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Saturday, August 04, 2018 - 04:15 pm:

UPDATE:
Thanks to all who have followed this thread and helped so far.
After removing the inspection pan I have found that all four rods move back and forth with little effort. I take from this that all four rods should have shims removed -- correct? I have the book that explains how but I still have one question (at least one). Modern locking nuts have been used on the rods and from what I can see before disassembly there appears to be plenty of babbitt. The book mentions replacing all rod bolts. I think this means if they are not of modern manufacture like the one I have appear to be. My question is replace or reuse?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Garland E Pobletts; Naples Fl on Saturday, August 04, 2018 - 04:16 pm:

The cam gear did not appear to move when challenged as Harold suggested


Top of pagePrevious messageNext messageBottom of page Link to this message  By Neil Kaminar on Sunday, August 05, 2018 - 08:16 am:

Best advice is to replace the bolts. Get the correct ones from the parts suppliers. The modern locking nuts are OK.

If the bolts appear to be new, and are not stretched, you can re use them. Look at the threads. If they are stretched the threads will appear to have a coarser pitch in the stretched area compared to where the nut was.

It may be that the rod bearings are OK. Carefully peal off one shim on one side, re assemble, and see if you can hand crank the engine. If you can't, put the shim back. When you put the shim back, make sure it is straight with the rest of the shims and rod cap. Good luck.


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