Im curious on what a jeep engine is supposed to sound like ik they get noisy with age but i hear when theyre rebuilt theyre almost silent engines is that true?

 

Not true. Even at 49k and new stock exhaust, mine could be a little clackety when starting up on cooler days. Gets a lot quieter as it warms. Starts a little quieter when I'm running the summer weight oil.

 

When my TJ was brand new (in 2000) it was pretty quiet, but there was never a time where I'd have called it "silent". It was pretty quiet for most of the 300k miles I put on it.
My Dad's 94 XJ was a bit louder, even when brand new.

The closest thing to a "silent" engine I've ever heard (or didn't hear, as the case may be) would be my Mom's 2010 corolla when it was new and her 2017 Rav4 hybrid. Even the hybrid is only truly silent when it's running in electric mode.
On the other hand, my Dad's 2016 Tacoma is louder than my TJ was brand new.

No gasoline engine is going to be silent (or virtually silent), even with the engine brand new and all the accessory pulleys brand new. My mom's cars seem to have benefited from a good deal of engine compartment insulation in addition to being smaller engines.

 

 

Strange - my AX15 is smooth and quiet. It makes the usual whirring sound in reverse, but in all forward gears it's smooth and silent.

 

The best was the NV3550 5-spd in my TJ - with 4 miles on the Jeep that thing rattled like a box of marbles in neutral.

 

 

It's funny - I looked at a 2001 XJ when Jeep shopping and among the many things that were a big turn-off for me was that the NV3550 had was was best described as "It sounded like it was in reverse in every gear". (Being that the NV3550 failing is what killed my TJ, this was doubly concerning).
I drove the 95 that I ended up buying and the smoothness of the AX15 was a big selling point for me.

I have an exhaust manifold, cat and front pipe replacement on the To-do list (which will result in a complete "new" exhaust - muffler and tailpipe were done when I bought it 6m ago) - so it actually may not be as quiet as I'm perceiving it to be.

 

the reason i ask is during warm up my engine can be heard from a good block away when idling where as my neighbors beat up little kia can barely be heard like how?! you just hear the starter and then thats it nothing else where as my jeep sounds like starting a dragster (exaggeration) in a dead silent neighborhood and i notice it alot in drive thrus too i know its being picky but my friend has an 89 cherokee and his with 380k miles with stock exhaust and no engine work sounds WAY quieter than mine

 

 

thats what im suspecting now i did use muffler weld on a joint and it quieted it down but still drones a little so i think i got holes on top of my exhaust but engine wise mines a little clattery and ticky

 

X2 on that one. Mine is about like that. Then the engine, some days I wonder if she's making a "new" noise... next day it goes away...then 3 days later, it's back. lol. Welcome to the older Jeeps lol. They are what they are...

 

I'm wondering if that's par for the course on these puppies. I've noticed a little more of that now that I switched mine over to a full synthetic this last change. So right now, chalking mine up to that. I don't think I've got any rods slappin' rockers or anything. lol.

If you want to hear a really weird motor pop the hood on a newer Toyota with VVT-i.... now that's a weird one to me. lol.

 

Your buddy with the 380k may have had an easy life of highway driving and excellent maintenance.
My Dad had 400k on his original everything, never a bit of engine work.

Also I don't think Kia even started selling cars in the U.S. (at least under the KIA nameplate) until after the last XJ rolled off the assembly line.
I'm being slightly facetious - it was right around 00 when I first heard of Kia and a guy I worked with got one and they had to ship it back to Korea for repairs since they were so out of sorts with it being so new.

As far as your engine noise goes, I agree with the previous posters on exhaust leakage.
What tends to happen is that the exhaust manifold cracks - if you're stressing the engine or if you've ever had motor mount issues or if you have rust, or bad luck you could get a manifold leak.
That'll make it noisy, but it's old - it could be just worn parts too.

 

true and yes i have heard toyota engines they are noisy af but once you close the hood poof! all gone lol alot of cars i think is the fuel injectors and such which is odd because there was a brand new hyundai accent or basically any kia/hyundai gdi engine and they are very noisy engines. But then again nothing compares to a diesel engine