Yet another, cm2350 overheating

[Rawze]

* Did you replace that brass ring in the bottom of the thermostat housing when you changed the thermostat?.. did you install it facing the right direction, and did you make a tool to install the new one without buggering it up?


* Did anyone verify that the program in the engine has been updated and that it matches exactly for the ser# on quickserv. .. and not some "uprated" program for more HP?. - When there is any kind of issue, the program should be verified that it matches the engine exactly. -== and just because it is not de-mandated, does not mean someone did not screw with it ... HAVE THE SOFTWARE re-flashed to ensure no one monkeyed with it at some point.


* Will it actually pass an injector leak test?.. It sounds like you played "guess-and-hope" with the injectors without actually doing any proper leak-down tests. here is the test you should have performed. It should NOT leak any more than 4,000 psi in one minute...
http://rawze.com/forums/showthread.php?t...2#pid69262

* Has anyone bothered to replace the IMAP and exhaust back-pressure sensor on it.. AND TO VERIFY that the circuit for the exhaust BP sensor that runs thru the thermostat housing is not clogged up?. This will cause all kinds of h#ell for the engine and its combustion process.

* Has anyone bothered to look at the front/radiator with a thermal camera or verify that there is not cold spot(s) in the radiator?... for all anyone knows, some complete idiot could have poured a gallon of stop-leak in the coolant system at some point and clogged up half the front end, or some other part of the engine internally.

* When is the last time someone pulled the DPF out of it and inspected its face.. and the face of the DOC unit.. and the face of the SCR unit for soot buildup, etc... for all anyone knows one or more of them could be face plugged and trapping way too much heat into the engine.

* When the engine is turned over by hand.. it is really hard to turn? relative to other engines? .. I have seen alternators, fan clutches, and other external components cause the engine to hard-start (have trouble turning over when cranking them) and run hot all the time too.

* Does the truck roll well on its own?. .. any tires or brakes , or maybe a gearbox or tranny getting hot when you drive it a while then stop somewhere?.

* Is the radiator or CAC unit an AFTERMARKET BRAND ?.. OR oem>?.

* Does it have an after-market Brand of EGR cooler on it>?.. those things can literally kill an engine.

* HAS ANYONE BOTHERED TO do a proper CAC leakage test and also checked the entire intake air system + egr system for air leaks by pressurizing the whole engine up?. - significant air or egr leaks lead to the turbo over-working itself and causing trapped heat in the engine.

* Has anyone bothered to see if the overhead cam has slipped?. If it has then it can cause the engine to create all kinds of excessive internal friction and heat due to improper injection timing, etc.

* What does the regen history in Insite show>?. how often is it doing a rilling regen cycle and what are the resulting numbers on the far right?. -= Maybe post a pic of the regen history. + compare it to the engine hours to see if it is properly active.

* It should be noted, and you should also understand that the engine ECU itself is capable of overheating that engine and creating all kinds of excessive friction internally, so that it can warm up the DPF, SCR, etc. system, and this can cause the engine to run hot all the time,.. so do not rule it out as being unhappy about the exhaust system temps, etc.. but not showing codes for it.

* Anyone bothered to check the barro sensor in Insite and verify that it matches the current weather (millibars I think) and altitude for where you are?... A bad barro sensor can send the engine into high-altitude operating modes and make it run improperly, throwing no codes for it.

* What has been the fuel mileage been so far?... And if you drive it gently for a few days and keep the speeds down to 63~ish and not scream it down the roads.. keep boost to 20 lbs or less.. what is the fuel mileage then?.

* WHAT is the live mg/stroke being consumed for the engine while it is sitting there at idle?. Excessive friction in the engine will raise this number, so that is another thing to look at. You say that it sometimes dies when it drops down to an idle after running hard ... Could it be excessive friction somewhere causing it to stall out and die!. it would show up in the live mg/stroke readings if this were the case.

* Maybe someone should take it on a test drive and observe all the operating and emissions control logic.. check what the computer is actually doing to the engine?. Has to be done in Calterm...
http://rawze.com/forums/showthread.php?t...6#pid28636

- Anyone checked to see that the fan-clutch is not weak and slipping under load?... and that the circuit has full pressure on it?,... and that the solenoid is not plumed backward?.

- And by the way.. if that egr cooler was leaking then those exhaust cans are most likely toast!. the coolant washes out the precious metals.. and most of the time it also face-plugs them .. so that needs to be looked at.

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At the end of the day.. abnormally high heat buildup in an engine is typically caused by 3 things.

A)> excessive friction somewhere, of which the fuel mileage will be respectively low to also show all the extra work performed that should not be. Friction could be in the engine itself, in the drive train, or in the front end pulley system. - I.E.> the engine is being over-worked vs. the amount of expected output to the wheels.

or

B)> improper cooling due to restricted air thu the radiator system, restricted intake, restricted exhaust, restricted coolant, or restricted oil flow.

C)> Improper combustion process control due to bad sensors, slipped cam, or some other input that keeps the engine computer in the wrong operating state or mode. Bad delete programming is notorious for this, hence why the engine eats its own guts out slowly. In your particular case, you say it is NOT de-mandated.. but the symptoms you describe very closely resemble exactly this.