The Stovebolt Site Forums The Shop Area Engine Shop 235 constant tapping when running.

Got my 235 in the 59 running and I have a question about the sound of the engine.
It runs great and sound great but there is a constant rattling tapping sound that is very consistent when idling, when I accelerate I cant hear it anymore. Its not knocking and it doesn't sound like a rod. its a constant purring
If I had something to compare it too I would compare it too the tapping of a good running VW air-cooled engine tapping sound of the lifters, or a diesel motor.
Its not super loud but you can hear it best when you are in the cab, in the cab you can hear it really good. Out side of the cab its a faint sound.

This is my first inline 6 I have owned or worked on or even been around to see hear or run.

It not smoking or cutting out.
It runs and Idles great.
It starts right up when warm, push the button and before one second the engine is running on its own.
Took the valve cover off and there is oil all over the rockers (looks good to me).
Its not "dieseling" or running when I turn it off.
There wasn’t any sludge on the topside of the head.

Is this what I want to hear in a good engine?

as 2many sez, may be adjustment, but the 235 likes to be a touch noisey at idle - too quiet burns valves - careful of fixin what's not broke!

Bill

Yep. Lifters. Even when adjusted properly, with solids you will have some ticking, especially if you adjust them to the heavy duty specs.

I Agree with the lifter adjustment. the early models had solid lifters and at an idle they talk to you. As the rpm increses the oil pressure quiets them down. The later models had the hydralic lifters and they are adjusted to be quiet all the time. If they're the solid lifters a little chatter is a good thing.

I've always heard that a noisy lifter is a happy lifter. If they are too tight they will run the cam flat as well as burn the valves.

I suppose I will leave it as it is, get the brakes done (2 more weeks) and drive it around for a while and see what happens.

If the brakes start tapping.....

No olblu... Getting the brakes done is my next step to getting it on the road.
I wish the brakes were tapping, they arent doing anything right now.

Hydraulic lifters can cause that too, if the lifter gets stuck. Or if it's just out of adjustment.

Ham-

I'd definately give it a good test drive before you start on the brakes. Just to be certain it is running good...

You know my 235 in my '46 2 ton was a noisy chattery critter like that too at first.

Like you, i'd not ever heard a "right running" one to know if the chatter was normal or not.. it had a kind of diesel motor sound, but otherwise ran great.

What I discovered was that these motors are supposed to have pretty heavy oil in them.. and i'd put 5W-30 in it with the first oil change.

Putting heavier oil in it quieted it down quite a bit.. it still chatters a bit, but not nearly as much as it did with the thin oil in it.

I just put 30 single viscosity oil in it due to the fact that I'm in CA. and it rarely drops below 45 degrees here.
I did run it with the old oil which I don't know what it was since it was in there when I got it and it was a lot quieter... now that I think about it.
I changed the oil and then I really noticed the chatter. But I didn’t put 2 and 2 together until now that you mentioned it Fumblin-49.
With the old oil the engine warmed up a lot quicker, with the 30 I put in, it takes a lot longer to warm up now, way longer and it warmer out side now.

I recon Ill change it to 5w 30 and if that doesn't help ill bust out the old shop manual and check the valve clearance.

By the way I really love the sound of that straight 6 it really surprised me how good they sound.

Thanks fellow bolters,
Billy the green horn