Cm870

[Benjamin9669]

Riddle me this.

Isx 475 cm870.
I am trying to see if anybody else has ever had this issue. 3 weeks ago we had the oil cooler done, “claims there is no thermostat”. My only question. Wouldn’t a truck with no oil thermostat run 210-215? Not 240-245?. Well that lead to this last Thursday. Jake brake quit working on all 3 stages literally faded down to sputtering and puffing weak, oil temp started climbing again over 265+. Tuesday after I was told it has good oil pressure and to go ahead and run it. I was running down the road and I heard a big clanking sound and a shi#t ton of white smoke that the cars behind me couldn’t even see in front of me. Does this sound like an injector tip breaking off or more of overhaul time? 582,000 miles on. Before anybody asks THEre IS nO TuNE and it is
not deleted.

[Peashooter67]

Yes

Your oil cooler has a thermostat , if it didn’t you oil would be {rest of post removed. Incorrect info}.


Cummins part number 4952629

[Benjamin9669]

Thank you I kind of figured this to begin with lol. But did you read the other part?

[Benjamin9669]

And that is also how I know if that oil cooler didn’t have a tstat than 245 when the oil cooler was fixed is rather high and now it was over 265 and something blew apart. The mechanic was a dumb f$%k to begin with. I felt it in my gut last thursday when I lost Jake’s and oil temp started climbing something wasn’t right. He said egr valve is shot and controls the Jake’s and oil temp.

[Rawze]

(09-21-2023 )Peashooter67 Wrote:  Yes

Your oil cooler has a thermostat , if it didn’t y{part of post deleted}.


Cummins part number 4952629

The second part of your statement is incorrect and was removed.

(09-21-2023 )Benjamin9669 Wrote:  ... 3 weeks ago we had the oil cooler done, “claims there is no thermostat”. My only question. Wouldn’t a truck with no oil thermostat run 210-215? Not 240-245?. ...

Also.. you are incorrect as well, because some complete dips#it must have given you some bad information, and if they removed that oil thermostat.. YOU NEED TO RE-INSTALL IT A.S.A.P!@.



===========
IF the oil thermostat was removed or missing,.. the oil will overheat on a whim.

This is because the oil thermostat is normally open and BYPASSING THE OIL COOLER!...






.. AND CLOSES AS THE OIL GETS HOT... BLOCKING OFF THE BYPASS CIRCUIT AND FORCING THE OIL thru the oil cooler as it gets hot.



I.E.> ...
WITHOUT THE OIL THERMOSTAT INSTALLED.. THE OIL WILL OVERHEAT VERY QUICKLY because there is nothing at all forcing it thru the oil cooler any more, AND THE BYPASS CIRCUIT THAT IT SITS IN, IS ALWAYS WIDE OPEN!.



If some complete dumb$tard told you to remove it, or that it did not have one, then they are a complete idiot!.

[Benjamin9669]

Before you go assuming. No. I am just going off what the dumbass said. He said “there is no tsat” on these 870’s. “It depends on the climate”. I am literally just going off what the dumb ass said. I know they have a tstat. I tried telling him there is one. Many times.

[Rawze]

(09-21-2023 )Benjamin9669 Wrote:  Before you go assuming. No. I am just going off what the dumbass said. He said “there is no tsat” on these 870’s. “It depends on the climate”. I am literally just going off what the dumb ass said. I know they have a tstat. I tried telling him there is one. Many times.

You need to ensure that whoever did the oil coolers made sure the thermostat was installed... and that it was functioning properly.

NOTE: Some ISX models only have a single oil cooler element in them, some have dual elements. Depends on application, but ALL ISX's have an oil thermostat, and a minimum of at least ONE oil cooler element.

You stated you "had the oil cooler done".. and that some complete idiot told you that there was no thermostat?. This would make me really question their ability to work on these engines.. as EVERY SINGLE CM870 ISX HAS a DAMN OIL THERMOSTAT!!!.. AND IF THEY SAID THAT NOT ALL OF THEM DO, >>> then for all you know at this point.. it could now be missing!.

The oil does not overheat as badly as you describe unless something is very wrong. A missing oil thermostat after the oil coolers were re-done, could very well be the case.

People do dumb things!... They do stupid s$it like removing the oil thermostat, so if you are not the sole original owner of the truck since brand new .. someone somewhere .. or that idiot who did the oil coolers.. could have very well removed it like a dumb s$it .. and this certainly would cause the oil overheating issues that you are asking about.

It could also simply be that the oil thermostat that is stuck open, and failing too.

SO..,. the next step, after verifying that it is actually overheating (oil temp sensor is not reading higher than it should), it looks to me, like it is to replace the oil thermostat and go from there... and believe me, replacing that oil thermostat is not such an easy task.

[Benjamin9669]

Yes. But it’s now going on for possible a rebuild. Tuesday it made a nice loud clunking noise and white smoke after he told me to run it. Jake’s quit working Thursday, oil temp started climbing on Thursday also after that. Tuesday. Clunk and white smoke to the point you couldn’t see one second behind you. So I am hoping it is just a bad injector but never had codes for it never had nothing. Ran perfect, the guy said the egr valve was shot causing high oil temps and Jake not working which I knew was bs.

[Benjamin9669]

Not the mechanic that did the oil cooler but a reputable shop.