Community Forums

Onrecess · 07-17-2021, 09:13 AM

I have a ISX 525 in my 2003 Sig. My wife has stood to the side behind. I had only heard the engine outside at idle. I was at LazyDays getting my slides fixed a few weeks ago. When the mechanic came to get the coach from camp/parking, I walked over to where he would drive by.
Driving, I can barely hear the engine. When he drove by I was very shocked how loud it is. My wife laughed because she has heard it when we move from storage or by the house.
I drove a semi for a few years, so I am no stranger to the engine sound. I was just fooled because the coach is so well sound insulated I thought it had a really quiet muffler. Haha! I guess not.
Cars must hate me. I have to drive two blocks thru a neighborhood to get to storage. I am going to be a lot more considerate with my use of the throttle. I step on it pretty hard from a stop sign.

CountryB · 07-17-2021, 09:33 AM

It's a big engine

It least your not "rolling coal" into other cars' faces like some of the modified pickups.

wolfe10 · 07-17-2021, 09:46 AM

Wonder if someone removed the OE muffler and substituted a "more free-flowing" one???

Timaz · 07-17-2021, 09:50 AM

Mine is also pretty loud. That's the advantage to being 40' in front of it.

Tim

Onrecess · 07-17-2021, 11:06 AM

Quote:

Originally Posted by CountryB

It's a big engine

It least your not "rolling coal" into other cars' faces like some of the modified pickups.

Ugg, I hate those jerks.
In traffic, the exhaust noise is what it is, but I can't complain about the idiots thumping bass in the neighborhood if I am not being a good neighbor myself. Adding a minute or two while in the neighborhoods isn't anything.
With trucks, the really loud jake brakes are posted in a lot of towns. I cannot hear mine at all, are ours that loud or are they muffled?

oldmattb · 07-17-2021, 12:03 PM

Quote:

Originally Posted by Onrecess

With trucks, the really loud jake brakes are posted in a lot of towns. I cannot hear mine at all, are ours that loud or are they muffled?

Likely two different things. The "Jake" on an RV is typically an exhaust back pressure device, a flap in the exhaust system. Relatively quiet. Often a Pac Brake.

The semis have a cylinder compression release, and it can be very loud.

vito.a · 07-17-2021, 12:53 PM

The ISX is a big 14.9L engine and it has a 2-stage Jake brake (some have 3 stages).

Just make sure you aren't hearing the fans running wide open.
The ISX uses a Sauer Danfoss electronic fan control and they have a tendency to fail. When they fail the dual hydraulic cooling fans run wide open.
https://www.irv2.com/forums/f115/fan...en-376611.html

**pasdad1** · 07-17-2021, 01:28 PM

Yep, On my ISL 9 what I hear most is the direct drive fan noise. Freightliner didn’t put a fan clutch on mine, the gearbox to the side radiator fan is direct drive…..as engine speeds up in first gear towards 2000 rpm the fan sounds like a jet engine !

YC1 · 07-17-2021, 02:13 PM

For those of us that have a rear radiator fixed fan blade check out Source Engineering.

I changed mine long long ago. The noise dropped 5db. I can now use the sound in my rear camera if needed.

The hurricane would nearly blow my hat off when standing outside and indeed the neighbors heard me coming.

The fan noise is not the only benefit. My mileage increased and the acceleration increase was noticeable.

Onrecess · 07-17-2021, 06:10 PM

Good to know about the jake. I don't have to shut it off where those no jake signs are. And it was definitely engine exhaust roar. The tech was coasting by and, when he saw the intersection was clear, stepped on it. I was stunned. I said it was loud as heck, and my wife laughed and said well, yeah.
Thanks!