ISX

[oldcoon]

What year did the valve issue get fixed on the 600 ISX. Interested in a 2016 LA but concerned about the motor issues

[tom chelbana]

The one ISX engine having the most valve problems are the 650 HP engines in the 2008 to around the 2012 model years. Remember the year of the coach isn't always the year of the engine. Sometimes it can be a two year older chassis then the coach build. Look on engine tag to find the year of the engine. There have been far fewer issues with all ISX engines in RV's in the 600 and 525 HP level. You should be out of the problem years with a 2016 coach.
Newmar Man

[oldcoon]

Thank you. Very helpful information

[tommar]

After reading other threads, there have also been issues with the 600 h.p ISX; still the number 6 valve...

[pbensen]

Originally Posted by tommar

After reading other threads, there have also been issues with the 600 h.p ISX; still the number 6 valve...

[emoji1303][emoji1303]

[oldcoon]

How about the 605 hp?

[spuds]

Originally Posted by tommar

After reading other threads, there have also been issues with the 600 h.p ISX; still the number 6 valve...

Most of the discussion is in the Cummins board of the Engines/Drivetrains section of the forum.

Definitely the 600 and 650 ISX are at risk.

The newer X15 engines are a different design.