Engine: Tapping noise in my engine when warm?

[Ken Stewart]

When I first start my 39 Commander the engine sounds like a Thoroughbred. As I drive it and get in the mountains on a hard pull I hear a tapping from the engine. The engine has to be very warm to hear it. then when I get home and in the driveway I can still hear it. What a piston slap sound like? Today I am going to get the engine warm up so I can hear the tapping. Then take a Screwdriver and ground each cylinder out to see what I hear. Not sure if it a rod knock or main. I just don't know. Really afraid to take the 39 on tour because of it. If I knew what the tapping or knock was I would know what to do with the engine. I did put a overdrive in the car that works very nice thanks to Jerry. What should I do maybe just drive it and see what happens. I did trade for a 245 engine with a overdrive. It needs complete rebuild and what shape it in ??? Maybe today a nice long test run to see what happends.

[345 DeSoto]

Try a quart of Rislone to clean out the oil system...

[jnormanh]

When I first start my 39 Commander the engine sounds like a Thoroughbred. As I drive it and get in the mountains on a hard pull I hear a tapping from the engine. The engine has to be very warm to hear it. then when I get home and in the driveway I can still hear it. What a piston slap sound like? Today I am going to get the engine warm up so I can hear the tapping. Then take a Screwdriver and ground each cylinder out to see what I hear. Not sure if it a rod knock or main. I just don't know. Really afraid to take the 39 on tour because of it. If I knew what the tapping or knock was I would know what to do with the engine. I did put a overdrive in the car that works very nice thanks to Jerry. What should I do maybe just drive it and see what happens. I did trade for a 245 engine with a overdrive. It needs complete rebuild and what shape it in ??? Maybe today a nice long test run to see what happends.[ATTACH=CONFIG]55306[/ATTACH]

Piston slap will be at its' worst when the engine is first started from cold, gradually lessening as the engine warms up. It sounds like tonk-tonk-tonk-tonk.

Rod knock usually can be made to come and go depending on throttle opening, and may be at it's worst when backing off. It sounds like rap-rap-rap-rap.

Worn mains are usually more of a growling sound.

Worn lifters might go tick-tick-tick.

And there are other possibilities: Loose flywheel, bad water pump, fan blade, etc.

A long run to "see what happens" might result in a broken rod or crank and $$$$ damage.

Find a real old school mechanic, have him give a listen.

Back in the 1950s we drove to California in a nearly new Packard, flathead 8. A hundred miles out, the engine started to make a fairly loud tick-tick-tick. The next day my father took it to an old school mechanic. He listened for a minute, then put his hand on the oil fill pipe, gave it a little shove. Problem solved. One of the crank throws had been ticking the end of the pipe.

You might get lucky.

[Ken Stewart]

Back from test run and it not a rod knock. Its not a main either. Most all the old timers are gone around here. I miss them. When I was young I use to get a lot of ass chewing because I was pretty wild. I had a 49 Dodge coupe and had 11 motors in it. Most all the motors came from the junk yard. 30 bucks for one back then.

[55 56 PREZ 4D]

It happens so slowly you don't realize it.
I was on a job site, sitting at lunch with a couple guys, talking about not seeing any of the old timers around in quite a while.
After one guy named several of the old timers a puzzled look came over his face, then a look of realization.
"Oh, Yeah, We're the old timers now !"
By the way, I lived very near Garrison, Pa for quite a while. Miss it.

[Ken Stewart]

Sure a small world isn't it. I like driving my 39 when the weather nice. It only has 46,000 miles on it.

[dpson]

Okay lets face it, we are now the "old timers"...

Almost sounds like pre-detonation knock, at least on the long pulls, check the ignition timing, also check if the vacuum advance is working?

Same noise in the driveway, not so sure about that, possibly a loose valve tappet adjustment?

[57pack]

Had a fuel pump on a 1956 Mercury make that noise after a good warm up.
Had a dual diaphragm fuel pump with vacuum wipers. Frank Todd rebuilt the fuel pump, no more knocking noise.

[jbjr]

I had a similar problem on my 259v8 and it turned out to be the rubber cushions on the vibration damper were crushed. After replacing them it was fine. It sounded like a valve and was keeping time with the engine.

[Ken Stewart]

I want to thank you fellows for your input on this. If I find the problem I will let you know. Being the only Lone Wolf Studebaker fellow in the area sometimes???? You fellow are a great help. I would have been lost what to do several times. I got my overdrive from Jerry Kurtz. Wish I was close to him. He one sharp fellow. I did get to meet him on the Glidden tour a couple of years ago. I want to get this Studebaker in shape to drive across country. I do need to get a extra generator, fuel pump, water pump, Coil and dist. cap, and points. Maybe a Master cylinder also. I have a 39 Ford Conv. that I drive all over the country. I have all those parts in the 39 Ford just in case. Better go now brain starting to smoke a bit.

[Chipmaker]

A wristpin with excess clearance can make that kind of racket.The fix was-is to ream piston and uper rod bearing(or rod)for a oversized wristpin.But check every thing else first.Hope it is not that.

[TWChamp]

I wouldn't carry around heavy parts like a generator. A restored generator should outlive most of us. I do carry points, condenser, fan belt, and a spare fuel pump, but don't feel the need for any heavy parts that have been restored.

My fuel pump also made a ticking noise. The crap gas took out the diaphram, so now I'm using a Holley electric pump, but plan to go back to the original pump sometime.