loudness of engine
 

Ok, I am a mechanic and i own a 2000 24 valve, that i absolutely love. I just got a chance to work on a 1997 12 valve, the 12 valve seems much quieter, and not a clacky as my 24 valve, is this normal, the 12 valve has 121000 miles on it and my 24 valve has 145000 miles on it, i just dont know if my truck is supposed to be as loud as it is, any input would be greatly appreciated.

Thanks,

Harold

Yes, the 24v's are noticeably louder, and I've never noticed but people say the 01/02 trucks even louder. Your valves might need adjusting as well though.

Some of that noise you are hearing could be the injectors. When I run two stroke oil in my fuel, I can hear the engine get quieter after a few miles.
Now that I haven't been running any additives at all, I can definitely tell it is louder....
Drop a pint (one of those little 50-1 bottle and make sure it is TCW-3) in the 24v at your next fill up and see what happens...

and there is a problem with it being loud?

If you want it REALLY quiet, try adding 2 pints of oil. Plus you get a really cool blue cloud of smoke at idle. :)

I like them loud, especially when people are on cell phones and their windows are down at stop lights...[laugh]

You might not notice the change now but as time goes by the hearing damage continues. When I started with my last company I had to have a physical which included a hearing test and when I retired a few years ago I had to have the same test. There was hearing damage in certain ranges, I'm not saying it's from the Cummins, it's just from noise......[tapdshut]

My hearing damage is worth it. It's in the same frequency range as my wife's voice.... Just kidding. A little bit....

^^^^^^ Hahahahahaha!!!!

They do sound different, I had my 02 and my buddy's 08 and 97 all next to each other idling one night. That 02 24v was the loudest for engine noise, the 08 sounds like a gasser, and the 97 was little quieter on the engine but the stacks made the exhaust seem louder.

I never said that there was a problem with it being loud, i just love pulling up next to the kids in the hondas, for two reasons, A: my exhaust is about eye level with them, B: when they have on their loud obnoxious music, all u can hear is CTD, and finally, knowing that i can blow them off even without the EDGE [laugh] thanks for all of your imput

i think the 01 and 02's were louder if they are the HO, we have one at work and it is pretty loud, i like my 12v even if its not as loud, plus the 24v doesnt have the cool ticking noise all the old cummins motors have

The HO's are louder because they have a higher compression ratio (17:1 compared to 16.3:1) Remember they also have different pump internals and the injectors flow less (600cc's compared to 640cc's)

I know first hand if you increase injector pop pressure, the engine noise from a diesel will be louder. I experimented with changing injector pop pressure on my Mercedes and Nissan IDI diesels when I installed new nozzles.

The HO engine injectors may have had higher pop pressure than the SO and I bet the 24v engines in general had higher pop pressures than the 12v engines. Also, the CR engines do not use a 'pop' style injector. The fuel pressure is always high, and the injection event is controlled via a solenoid.

engine tones?
 

I have a theory on that, mine has been underfueling since new! It revs and screamed for most of its life. It is the amount of fuel being injected into the cylinder. Mine fuels in the 1450 to 1975 rpm band, sometimes it will fuel highter up, the tone changes as this happens. It sounds very tinny, not like Bach! Just out of hi school I got to work with aircraft and the L-19's had the 6 cylinder Lycombing engines, the 3 sounded different you could tell which one was taking off and landing.

[laugh]I was thinking the same thing. I love watching them or cell phone talkers roll up their windows. Filling their car with nice black smoke at take off if they don't is a bonus. As others have said, the 01 and 02 are loud. I have a buddy with an 05. You can't even here it idling next to mine.