Jump to content
Sign in to follow this  
OC Transpo/STO Fan

Difference between Cummins ISL9 and L9?

Recommended Posts

Sorry if this is the wrong place. I was just wondering about this. Is the Cummins L9 a new engine, or is it just a rebranded 2017 ISL9 with new EPA regulations? I know that the ISL9 was basically just a renamed ISL with 2010 EPA regulations.

Share this post


Link to post
Share on other sites
5 hours ago, Bus_Medic said:

D533A861-F126-4230-A828-34D75A4ED740.thumb.jpeg.37d998489f6e259d1f93e2dcc660d136.jpeg

I don't watch the Simpsons, but I'm guessing that the "new" L9 engine is basically a renamed ISL9. 

Do you know if there are any other minor differences besides the 2016 EPA regulations?

Share this post


Link to post
Share on other sites
48 minutes ago, OC Transpo/STO Fan said:

I don't watch the Simpsons, but I'm guessing that the "new" L9 engine is basically a renamed ISL9. 

Do you know if there are any other minor differences besides the 2016 EPA regulations?

Haven’t read up on them yet, to be honest.

  • Thanks 1

Share this post


Link to post
Share on other sites
On 3/31/2018 at 11:45 AM, OC Transpo/STO Fan said:

Sorry if this is the wrong place. I was just wondering about this. Is the Cummins L9 a new engine, or is it just a rebranded 2017 ISL9 with new EPA regulations? I know that the ISL9 was basically just a renamed ISL with 2010 EPA regulations.

There are very few differences between the two versions of ISL9's and the L9:

1) Additional independent cooling loop in the L9 that can be used to heat the passenger compartment. 

2) Increase in the particulate filter capacity

(unknown if general engine software and regen timing is the same)

Other than that, there is barely any difference between ISL9 (EPA 2010 and EPA 2013) and the L9 (EPA 2017).  They may sound different due to design changes of the exhaust system on the bus.

They all are almost identical in performance (plenty of torque, powerful and gutsy for transit buses), but the condition of the engine (old vs new, well-maintained vs no maintenance), and the transmission and shift programming will have the biggest impact on how they perform on the road. 

Refer to the website below:

https://cumminsengines.com/l9-for-transit-bus-2017?#overview

  • Like 3

Share this post


Link to post
Share on other sites

The “dual loop” coolant system is a good idea. More than half of external leaks are traced back to components in the body heat circuit. Having the level drop so low as to create any voids inside the egr cooler will crack internal welds and braising in the (egr) exchanger tubes, (in very short order too boot) introducing coolant into the engine intake manifold. Never a good thing. Junks up a very expensive catalytic converter module too.

a cracked egr cooler will also cause the system to be unable to pressurize at operating temperature (about 190F), causing the coolant to start boiling, compounding the situation.

Also gives us limp home capabilities should the body heat system spring a leak that we can’t isolate on the road.

  • Like 2

Share this post


Link to post
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
Sign in to follow this  

×