Discovery: 2014 Discovery 40X engine?

[Broncoflyer]

Looking at a 2014 discovery 40x, trying to find out what engine is in it. Its either an 8.3 isc or the 8.9 isl depending on what web page i look at. theres a big 380 hp sticker on the rear cap but that doesnt help. Anyone got one that can tell me whats actually in it?

Thank you

[Skip426]

Get the chassis serial number (VIN) and call Freightliner's free help line .

Could be the 8.9 was an option and only the chassis manufacturer will know for sure.

1-800-385-4357

[Gary RVRoamer]

According to the FCCC (Freightliner Custom Chassis) website, the 2014 Discovery with the 380 hp diesel has the 8.9L ISL9 engine. The same coach in 2013 had the ISC 380 hp.

Cummins ceased production of the ISC for highway use in the USA in late 2013. It may be that a few early production 2014 Discovers had 2013 chassis with the ISC, but the standard production would have been a 2014 chassis with the ISL9.


As suggested, call FCCC Customer Support at 1-800-FTL-HELP and have the last 6 digits of the VIN handy. They will answer all your chassis/engine questions.
Here is the cahssi spec sheet from FCCC:
https://cdn.fccchq.com/specsheets/20...-Discovery.pdf

[Broncoflyer]

Thank you for the help. It's the ISL 13 according to the guy at that freightliner number.
Now to do so e reading and find out if that's a good or a bad thing. Skip426? I'm just outside of Vanderhoof and we just had snow yesterday.... gotta love northern bc

[Skip426]

Originally Posted by Broncoflyer

Skip426? I'm just outside of Vanderhoof and we just had snow yesterday.... gotta love northern bc

Powell River under a rainfall warning .
I'm 27 miles south of Lake Havasu City ; 25C , cloud count ...zero.

BUT; I have to be home by April first.

[wolfe10]

Originally Posted by Broncoflyer

Thank you for the help. It's the ISL 13 according to the guy at that freightliner number.

I don't know what a Cummins ISL 13 is. The ISL is a Cummins 8.9 liter engine.


They could be ordered with an exhaust brake (less $$) or true engine compression brake (more $$$)

[dons2346]

Look at your exhaust brake switch.

Is it a two position on or off? If so you have the ISC
Is it a three position switch high, low off? Then you have an ISL

[wolfe10]

Originally Posted by dons2346

Is it a three position switch high, low off? Then you have an ISL

Agree, the ISL CAN be had with the more effective engine compression brake with HI and LOW settings.


But, it can also be ordered for less $$ with an exhaust brake.


Absolute answer is to call Cummins with the engine serial number. OR if you know what you are looking at see if it has an exhaust brake (external to the engine on the exhaust just after the exhaust manifold).

[Broncoflyer]

Wolfe 10, ISL 13 is what the guy at Freightliner help line called it. Confused me too until I found a reference to an ISL10. Best I can figure is that the number is referencing the version year. So I think it's a 2013 Isl 8.9liter in a 2014 coach. I can't check the exhaust brake switch cuz I don't own the thing yet..... but that will change in a week. 8 more days......

[Broncoflyer]

The 2014 fleetwood manual shows the switch in the cockpit of the discovery and providence models as an engine brake. Next page on an excursion diagram that swit h is labeled as exhaust brake. Guess I'll just have to wait until I'm in the seat to find out..

[Gary RVRoamer]

It's the ISL 13 according to the guy at that freightliner number.

There is a variant of the ISL9 engine that conforms to the EPA 2013 regulations. Cummins calls this an ISL9 (2013) to distinguish it from the older EPA 2007 and EPA 2010 variants. I'm guessing that is what the FCCC guy meant, but it is confusing to mix EPA spec levels with engine block sizes.


https://www.cummins.com/engines/isl9...20RV%20Engines

[Toribk]

The ISL9 (8.9 Liter) is the older brother of the ISC 8.3 Liter and is equipped with Variable Geometry Turbo used for (exhaust) supplemental braking.

From Cummins:


The VGT Braking Assistance (ie Retarder)works in conjunction with the engine and transmission to provide an integrated braking system to help slow the vehicle. This is commonly referred to as exhaust braking. Braking power is achieved by modulating the sliding nozzle ring to restrict the flow of exhaust gasses from the engine, this will create high back pressure on the engine. The high back pressure creates a high level of resistance to the motion of the pistons within the engine and this resistance is used to reduce engine speed and thus vehicle.

The exhaust brake feature will only function when the Exhaust Brake/Retarder Switch is in the ON position.

With the switch in the ON Position and the vehicle moving faster then 5 MPH; the exhaust brake will automatically operate when pressure is removed from the accelerator pedal allowing the ECM to see 0% throttle and 0% fuel delivery.

[wolfe10]

Originally Posted by Toribk

The ISL9 (8.9 Liter) is the older brother of the ISC 8.3 Liter and is equipped with Variable Geometry Turbo used for (exhaust) supplemental braking.

Actually, the Cummins ISL (8.9 liter) is the YOUNGER brother to the ISC (8.3 liter) which has been around a lot longer than the ISL.


The ISL IS the bigger brother (8.9 vs 8.3 liter).


I relate-- my younger brother is also larger than I am.

[Toribk]

I apologize for the confusion Wolfe10, my use of the word "older" brother was to imply the newer larger version of the ISC indicative of the 8.9 (ISL9) designation and not the length of time in production.

I'll be more careful in my selection of words in the future.😉