making diesel engine run quieter

case685 · Feb 19, 2006

Hi I was wondering if anybody had any advice on getting my Case 685 diesel engine to run quieter. Although it seems to run good I find it to be loud. It is a 4 cylinder 60 hp with aprox. 4500 hrs on it. I don't know if the tappets have ever been reset or if that would even make a difference. Also I'm wondering if I can put an oversize muffler on it and what type I should use.
I've noticed to on most newer tractors that the engine area is completely shrouded and was wondering if that would help to reduce engine noise. Thanks

RalphVa · Feb 19, 2006

Think I'd check the valve clearances, if this has never been done. Even a gas engine with mechanical tappets will get pretty noisey with lots of miles. It could reduce your fuel consumption (after resetting), too, if the tappets are so loose that they're so noisey. You'll always have the diesel rod clatter though.

Ralph

Mike_Lipke · Feb 19, 2006

If the valves have never been set, or have not been set for a long time, you really should do it, or have it done. If they are looser than spec, not only will they clatter, but they are not opening up enough, and opening late and closing early. In other words, valve timing is late, and you are sacrificing power and economy. The dealer should be happy to give you the specs, set hot or cold (probably cold, or under 100 degrees) and of course a new valve cover gasket.

5030 · Feb 19, 2006

( You'll always have the diesel rod clatter though. )

Ralph:

What on earth is diesel rod clatter?? Don't you mean injection noise?

jimmysisson · Feb 19, 2006

Actually, I've wondered how to turn over a diesel to set the valve clearances. You can't do it manually, the way we used to with gas engines, right? Stop valve pulled out and bump the starter? Loosen the injectors? I'd like to set mine to see if it quiets down a bit, but my owner's manual is mum on the topic.
Thanks, Jim

Mike_Lipke · Feb 19, 2006

You prolly have to take loosen an injector or glowplug to eliminate compression, then turn it over with a socket on the fron or rear pulley bolt. Starter bumping could take a week or two to get to TDC.

robison · Feb 19, 2006

Often a quart of ATF added to a full fuel tank will reduce diesel clatter. The advice about valve adjustment is good, also.

markct · Feb 19, 2006

( Actually, I've wondered how to turn over a diesel to set the valve clearances. You can't do it manually )

ya cant? i always turned them over manualy with a ratchet and socket on the front bolt, or with a chain wrench around the front pulley. the cummins engines use a tool that looks like a starter pinion gear that goes into a hole in the block and engages the flywheel. then you turn that with a ratchet. but either way, turning it over with a wrench is the easiest way

MMM · Feb 19, 2006

I believe he's speaking of exhaust noise, not the wondrous, exquisite sound of a diesel engine running. Do we want our tractors sounding like Nissan Sentras?
There was an underslung exhaust option for the 685. Much quieter, but might be spendy if you have to get it fromCNH.

JerryG · Feb 19, 2006

I have a good friend that has a welding / muffler shop. He does a lot of off road equipment, big trucks, buses as well as cars and pickups. If you can find a shop that is like his, they will be able to fix you up. A larger size is not always the answer. You don't want to over due the back pressure among other things. A shop that knows there stuff will be able to make a good recommendation for your exact situation. I don’t know if you are like me but I can't stand a noisy piece of equipment.

HGM · Feb 20, 2006

( Hi I was wondering if anybody had any advice on getting my Case 685 diesel engine to run quieter. Although it seems to run good I find it to be loud. It is a 4 cylinder 60 hp with aprox. 4500 hrs on it. I don't know if the tappets have ever been reset or if that would even make a difference. Also I'm wondering if I can put an oversize muffler on it and what type I should use.
I've noticed to on most newer tractors that the engine area is completely shrouded and was wondering if that would help to reduce engine noise. Thanks )

Can you clarify the type of noise youre concerned about?

Exhaust noise can be muffled with a larger, or even different configuration of muffler..

Valve noise can surely be quieted by adjusting missadjusted valves..

Diesel "knock" can be due to incorrect injection timing, bad injectors, poor fuel quality, lack of fuel, and on and on and on........

Makes a difference... If theres nothing wrong and you just dont like the diesel sound, no theres nothing you can do.. Although you may want to try a fuel additive/cetane booster, to see if it helps...

IH3444 · Feb 20, 2006

More than likely an older direct injection engine. My IH BD154 engine is noisey. Setting the valve adjustment helped a bit, could put additional muffler on it. The direct injection engines are noisey just by the nature of the beast. Shrouds with muffling material will help also. Look under the hood of any modern day car, especially the diesel Mercedes, and Volkswagens. See that material attached under the hood. That the stuff you want inside your shrouds. Me? I just put ear plugs in, and go about tractoring. Must admit tho, the NH TC48DA is a quieter machine, but it is indirect injection also. Good luck! /forums/images/graemlins/smile.gif

Jagmandave · Feb 20, 2006

Why can't you just use the compression release so you can turn it over by hand (or with a wrench)?
Yes I realize you then have to release the release to adjust the valves, but it should make it possible to turn it over to the correct position to make the adjustments.

geneP · Feb 21, 2006

I have a CaseIH 385, little brother to your tractor, and it's noisy too. My exhaust is under the tractor and it's still noisy from the engine area. Using a C-tane enhancer helps the noise at idle some, but I think they are noisy by nature.

MMM · Feb 21, 2006

No such thing on this engine.

normde2001 · Feb 22, 2006

It totally depends on what is making the noise, exhaust, plain old diesel knock, or loose valves, (which you probably can't hear on a diesel tractor anyway for all the noise).

SailorBob · Feb 22, 2006

I can't believe it is any louder than a "Yammer Hammer". I guess I am just used to the noise. Although they do quiet down a bit after they warm up..

tkcomer · Feb 23, 2006

It’s exhaust noise. I have the 685 also. They do have quit a roar to them. Though no louder than a normal large four banger diesel with out a turbo. Take my DX-33. You can hear the engine on it. Not so with the 685. The exhaust drowns out any engine noise. But they have a pretty good size muffler on them. You can see here: http://www.pixagogo.com/7000025205 I bent mine back bush hogging under tree limbs.

SailorBob · Feb 23, 2006

Nice tractor. The exaust noise is not bad on a Yanmar but, the engine itself is. I have to shut it down or walk a at least 20 ft away to have a conversation with anyone. I have heard but, not tried it that you can hear better with ear plugs than without.

RobJ · Feb 23, 2006

( More than likely an older direct injection engine. My IH BD154 engine is noisey. Setting the valve adjustment helped a bit, could put additional muffler on it. The direct injection engines are noisey just by the nature of the beast. )

Interesting, i worked on diesels professionally for years. The direct injections were always quieter than the indirects (pre-combustion chambers). Always more rattle because you got sort of a double fire, once in the pre-cup and the other over the piston. Back then these were used in mines and the pre-cups put out less emissions. I think my L2500 is an indirect, haven't pulled the head but that's my guess.