Knock sound coming from front of motor

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Model T Ford Forum: Forum 2014: Knock sound coming from front of motor
Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Fusi on Friday, February 28, 2014 - 01:57 pm:

New to Model T Fords and I could use another opinion. so any opinions/ideas/thoughts/remarks welcome.
1921 Model TT
Knocking noise coming from front of motor. Noise is at all RPM's (I'm not driving it since the noise started)
I removed the fan belt to eliminate that area as the cause of the noise.
To me it sounds like a Rod knock but there seems to be a vibration too, so I'm leaning to the front main.
This is a new motor, less than 500 miles (Reno shop).
Hoping for someone close might drop by, listen and share their thoughts.
Definitely don't want to tear into it before I have a good idea of the problem (and the cure).
Anyone near Selma California? come by and give it a listen?
thanks


Top of pagePrevious messageNext messageBottom of page Link to this message  By Gary London, Camarillo, CA on Friday, February 28, 2014 - 02:22 pm:

Have you tried calling the rebuild shop? No sarcasm there, I just think that would be the best place to start, and I'm sure the rebuilder will be concerned as well.....


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Fusi on Friday, February 28, 2014 - 02:27 pm:

Yes, I plan on calling the shop but wanted more to tell him than "I hear a knock".
thanks for you input.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan B on Friday, February 28, 2014 - 04:00 pm:

Check for a loose pin in the front crank bell housing. This is often a common source reported for the kind of noise you're describing.

If it's not that, telling us whether you hear the noise when the engine is under load can help determine if it is a main or rod knock.

Finally if it is determined to be a rod knock, by developing the sound at a particular RPM and then shorting out one plug at a time, you can typically narrow it down to the offending cylinder.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Richard Gould on Friday, February 28, 2014 - 04:29 pm:

Check to see you have the spring installed on the crank arm. I had a similar knock and discovered it was only the crank ratchet hitting the pulley pin.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Elliott on Friday, February 28, 2014 - 05:34 pm:

Timing maybe too advanced, but usually a front main


Top of pagePrevious messageNext messageBottom of page Link to this message  By Micheal Crowe on Friday, February 28, 2014 - 05:46 pm:

I had a knock in the front of mine. I was in Colorado on a tour and my crankshaft pulley broke. That was it, the knock disappeared.


Top of pagePrevious messageNext messageBottom of page Link to this message  By scott hohensee on Friday, February 28, 2014 - 05:55 pm:

Check on the condition of the generator gear and also the pin that holds it on the shaft if that pin is broke you will get a ratleing or knocking noise.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Friday, February 28, 2014 - 06:16 pm:

I had a very bad front main problem and it didn't knock at all unless the engine was under load or you revved it. I could coast downhill at 45 mph and everything sounded great, until you got back on the throttle.

Since Dave's noise seems constant, I'm thinking a rod. Dave, have you eliminated the possibility of the sound coming from your generator?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Fusi on Friday, February 28, 2014 - 08:10 pm:

Thanks for all the info.
I'll be checking to see what I find this weekend.

Spring is coming and I want to be on the road!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dennis Prince Madras, Oregon on Friday, February 28, 2014 - 08:56 pm:

Dave, You might try taking off the oil filler cap and see if you can get the cam gear to move at all in any direction. The cam gear may have come loose or if is a metal gear they can make some pretty bad noises. Good luck and keep us posted.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Paul Mikeska, Denver CO on Saturday, March 01, 2014 - 01:06 am:

Take the fan belt off and see if the knock is still there. Sometimes worn fan bushings can make a front motor knock.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Saturday, March 01, 2014 - 07:03 am:

Paul read the first post carefully......


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Elliott on Saturday, March 01, 2014 - 10:11 am:

Change the Oil, may have too much old gas in the oil and thin oil. I use straight 30 weight. No engine noise


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Saturday, March 01, 2014 - 12:15 pm:

It could be any of the above or something else. It could even be a combination of the above.

A few things other than what was addressed above. Loose piston in bore. Tight or loose wristpin. Loose rod bearing. Bent or misaligned rod causing a front to back movement as the engine runs. These can be caused by improper fitting. It will feel snug when the engine is turned by hand but actually has a tight spot which will quickly wear down leaving the bearing too loose. Another possibility would be using a fiber timing gear, especially with a generator. Unless all the gears are new and properly installed, the fiber gear can wear quickly causing a knock and eventually losing the timing. Or it could even be a vibration of some body part of hood which sounds like an engine knock.

However, it is kind of like going to a doctor. If you try first to diagnose the symptoms and tell the doctor what you think you have, he might get sidetracked and miss the real cause of the symptoms. If it were my engine, I would take the car to the rebuilder and let him listen to the engine and drive it around a bit. He very likely has a lot more experience and will be able to find the cause better if you tell him of symptoms rather than telling him the cause.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Erik Barrett on Saturday, March 01, 2014 - 01:13 pm:

Dave,
While running the engine, ground one spark plug at a time with a screwdriver. If the problem is specific to one cylinder, such as the rod bearing, wrist pin, piston, etc, the noise will stop or otherwise change.
I may be coming through there on the way to Long Beach soon. Maybe we could drop in for a look.
Erik 530 863 7579


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Fusi on Sunday, March 02, 2014 - 03:51 pm:

Update:
I shorted out the front cylinder and I didn't hear much difference in the noise.
BUT my hearing isn't so good and the sounds it different to me today. I didn't let it run as long today ... maybe needed it to warm up some more for the noise to amplify?
Now the big BUT ......... I looked in the oil filler cap to look at the generator gears (as advised) and notice some shiny material. So I ran a magnet around inside the hole and found one piece of ferrous metal (1/32 x 1/8). The shiny material appears to be non-magnetic ...... bearing material?
I guess I'll drain the oil and see what else I find.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Sunday, March 02, 2014 - 04:45 pm:

Dave,

After you drain the oil, remove the lower crankcase inspection cover and have a look around.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Norman T. Kling on Sunday, March 02, 2014 - 06:24 pm:

Try scraping the metal. If it is babbitt, it should be soft, harder than lead, about like solder. If it is babbitt, you need to see the rebuilder, because it is probably from the front main bearing or the front cam bearing. If it is hard, it could be a tooth from a timing gear. If you suspect a gear If you have a generator or alternator, remove and check the gear on it. Also turn over with the crank and look at the cam gear as you make two revolutions of the crank. You can check the crankshaft gear from the inspection plate under the engine. In either case, your rebuilder should make good. If not, let us know so we can boycot.

Norm


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Fusi on Wednesday, March 05, 2014 - 01:31 pm:

Ok Guys, here's what today's inquiry turned up;
Drained the oil, found some very small steel shaving (not much). The oil has something in it, my guess is a break in additive or assemble grease (lithium?)
I pulled the generator and the front timer gear cover.
The time gear is shiny and looks like metal but it's not steel (not magnetic). Not sure what it's make of? Alum alloy?
Also the edges of it are chipping off.
This would appear to be very small shiny flecks I found earlier in the oil fill hole.
I haven't figured out how to get it off yet, need a wrench with a pretty good off-set.
Probably have to bend one to get the off-set. or use the hammer & punch method.
As for the cause, not sure yet. or if this is even the knocking I'm hearing?
no chips or obvious damage on the generator gear.
I'll look at it more when time allows.
I would post some photos if I can figure out how.

PS the builder is being helpful and isn't a problem at this time.Alum Timer Gear Damage


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Wednesday, March 05, 2014 - 01:43 pm:

Dave,

If it were mine, I would turn it over to the rebuilder at this time. You have a clear & obvious sign that something is wrong. You've done enough detective work. Anything more you do, may give the rebuilder a reason to say that you're at fault. And, in fairness to the rebuilder, anything further you may do, may remove or confuse the root cause of this trouble, making it even more difficult to diagnose & solve.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Fusi on Wednesday, March 05, 2014 - 01:54 pm:

Thanks for the help everyone.

I'll be removing the motor as soon as time allows and be returning it to the builder.
He as been in the loop and seen the photos.

Again Thanks to everyone for their help. This is a great community.

DAVE'50 Ford and '21 TT Ford


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dan B on Wednesday, March 05, 2014 - 05:04 pm:

Glad to hear you're making progress. Keep us up to date too if you don't mind.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Robin Pharis on Wednesday, March 05, 2014 - 08:29 pm:

Dave if you checked all the above and it looks good it may be the front cam bearing since you have the front cover off you might make a thrust bearing between the cam gear and the timing cover. Glen Chaffin sell it


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ken Todd on Thursday, March 06, 2014 - 11:31 am:

If the rebuilder replaced the camshaft gear but left the old crankshaft gear in there, that may be the problem. New aluminum gears don't like to run w/old worn steel gears.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Thursday, March 06, 2014 - 12:17 pm:

Could be that if new cam bearings were used, there are some out there that were machined off center. Another thing is making sure the cam bearings fit snug in the holes in the block.
My engine has a knock some place in the front as long as I don't over advance the spark it's ok. Can hear the gears in front kinda (being kind on that one :-) ) making noise. I did the short test, no knocking.


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