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+--- Thread: rpms at idle speed up to 760 and hot exhaust lite (/showthread.php?tid=4841)
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rpms at idle speed up to 760 and hot exhaust lite - mike - 07-23-2019
Have a problem for a year now its happens every day fuel mileage drops rpms at idle goes from 700 to 760 rpms every day and hot exhaust light comes on ,take off at a light there is no pedal at first then it comes alive. fuel was running 8 to 9 mpg now 6.8 to 7.8 had a code come up 2 months ago had it cleared it was vg turbo controller the truck has not regen on its own, had to hook up to computer to regen it. ISX 15 , 870, 285,000 miles on the motor in a 2014 pete 587.
RE: rpms at idle speed up to 760 and hot exhaust lite - SquareOne - 07-23-2019
Have you performed an EGR tune up—— it’s due with those miles on it. Search with the bar on the top of the chat box and you’ll see plenty of very useful info about the topic.
This may very well be your issue. Regardles though, it should still be maintained for proper operation.
RE: rpms at idle speed up to 760 and hot exhaust lite - mike - 07-23-2019
I change the map and delta p clean cross over and most of the intake cleaned egr and doser injector
RE: rpms at idle speed up to 760 and hot exhaust lite - tree98 - 07-23-2019
Did you find out why you had a code for the turbo controller?
RE: rpms at idle speed up to 760 and hot exhaust lite - Rawze - 07-24-2019
the HET lamp is supposed to come on when it is performing passive (going down the road) regen, and you slow down below highway speeds. it is simply telling you not to park the truck in the grass, so nothing catches fire.
use insite to look at the regen history, post some screen shots of it for a second opinion.
btw: a 2014 truck would have a CM2350 model ISX, not an 870.
RE: rpms at idle speed up to 760 and hot exhaust lite - mike - 07-24-2019
Rawze the light comes on every day and sometimes 2 times it has a factory reman in it . It lost fuel pump took engine out, it was a pacar lease truck. the 870 has the egr on the tubro side and cross over pipe over top of valve cover I believe. would the vg restrict and cause it to do it had a code come up about 2 months ago give me 2 hours before shut down . had it cleared no more codes since then i will try to get somewhere to hook up to computer thanks
RE: rpms at idle speed up to 760 and hot exhaust lite - Rawze - 07-25-2019
(07-24-2019 )mike Wrote: ...
the 870 has the egr on the tubro side and cross over pipe over top of valve cover I believe
...
Not trying to be a stickler about it, just trying to educate here ...
That is actually incorrect. The 870 does not even have a DPF can,.. they were built and sold on trucks before 2007, and are an egr only engine, NO DPF, NO SCR, NONE OF THAT STUFF was on them, or part of trucks that had that model engine in them. --
It is not therefore possible to have DPF problems, nonetheless regen issues, or even a high exhaust temp lamp in the dash of a truck from back in 2006 or earlier, that had a CM870 engine.
Just an FYI: The CM2250 AND the CM2350 engines, BOTH MODELS have the egr crossover pipe going across the top front of the engine valve cover.
-- Trucks with ISX engines from years 2013 - 2017 are CM2350's. If you want to know the definitive answer to what model engine you have, then register your engine on quickserv.com and look at the data-plate info page, based on your engine serial number.
RE: rpms at idle speed up to 760 and hot exhaust lite - Rawze - 07-25-2019
(07-24-2019 )mike Wrote: Rawze the light comes on every day and sometimes 2 times it has a factory reman in it
...
as far as the HET lamp in the dash goes (assuming your not referring to the check engine or red shutdown light), I stated earlier...
http://rawze.com/forums/showthread.php?tid=4841&pid=41526#pid41526
RE: rpms at idle speed up to 760 and hot exhaust lite - mike - 07-25-2019
thank you for the help it was mfg. 8/13 i will try to get into someplace to check insite