06’ cummins overheating while towing uphill

[dirtbys]

I have a 06’ ram 3500 dually that was overheating while towing up hill. Had to stop several times to let it cool down. The temp would drop back down to around 200-210 in like five minutes or so. Runs fine when running with no load. Engine and trany got rebuilt last year. Radiator got flushed, new injectors, new turbo, new batteries, new water pump. Just had the ECM replaced a cpl months ago. Also it seemed to really be struggling. Pedal to the floor and was doing like 25mph

 

[RedneckHippy]

When is the last time you swapped in a new or cleaned air filter? I assume you’ve been checking out the dedicated Cummins forums?

 

[dirtbys]

i will have to check my records for the air filter, I don't think its been all that long but I will give it a look. Its the wifes truck and she hasn’t driven it much in the last few months since she has not felt very good and now with the current world issues it gets driven even less so it should be fine, but i will pop the cover and look. Sorry to say no I have not checked out the dedicated forums but i can do that after work tonight.

 

[dirtbys]

Also it has a 180 tstat in it and stock is 190. Would that be an issue?

 

[RedneckHippy]

Also it has a 180 tstat in it and stock is 190. Would that be an issue?

No, I don’t think so, how hot was it getting?

 

[dirtbys]

all the way to the right and check gauge light came on

 

[chri5k]

Did they bleed the air out of the cooling system? Sounds like there might be air trapped in the cooling system. Google 5.9 Cummins Bleed Cooling System and there are multiple pages and videos on how to bleed the cooling system. Essentially you have to remove one of the pipe plugs from the passenger cylinder head and fill the radiator until the air is no longer coming out from that plug.

 

[dirtbys]

would that be an issue all the time? or only show up under load?

 

[chri5k]

Depends on how much air. The air pocket degrades the efficiency of the cooling system. Under unloaded conditions the degraded system can still keep up with the heat being generated by the engine. Under load considerably more heat is generated by the engine and the degraded cooling system can't keep up. I like may engine to run cool. I have lusted after one of these Mashimoto radiators. They are a work of Aluminum and TIG welding art. They have about 40% more cooling area than the stock radiator.

 

[superjoe83]

I would make sure that the radiator is not packed up with junk that is caught between it and the intercooler, also check in between the a/c condenser and intercooler for debris.

Can you hear the fan speed up when it's running hot? Could also be a bad fan clutch

 

[dirtbys]

fan clutch is new, put a new one like last fall sometime, i will check in between the condenser and inter cooler as well as blow out the radiator

 

[dirtbys]

also wouldnt any air burp out thru the tstat or the overflow?

 

[crash68]

Sounds like it was struggling to pull, it's possibly a boost or fuel issue which could cause the overheating. When you were towing, how much boost pressure where building? Maybe change the fuel filters?

 

[dirtbys]

I will check the fuel filter and the truck doesn’t come with a boost gauge and I haven’t installed one yet I just ordered one for my other truck see how that goes and then I may put one on this truck as well. I do have the capability with my code reader to see what fuel pressure is when I’m going down the road so what should I expect for normal fuel pressure?

 

[dirtbys]

Ok so the fuel filter got replaced in Jan
The air filter is a 4" filter that's a little dirty but not to bad. Not sure if dropping to a 2" filter will help any
I don't think there is any air n the system. radiator and resivor are full and i am thinking the tstat would bleed out any air???
Fan clutch got replaced in Oct of last year so that should be good
radiator looks a little dirty so i can blow that out
The fins on the condensor are in really bad shape though so thinking that could be at least part of the problem
Fuel pressure is running between 111K psi to 123k psi while cruising at 65mph with very little load.

 

[crash68]

You might be able to read the trucks boost pressure sensor using an app called Torque (Fusion if you use iOS). You would also need a Bluetooth or WiFi OBD reader.
The sensor may read in absolute pressure instead of gauge pressure. Absolute pressure doesn't compensate for atmospheric pressure so it will read 14.7 psi when gauge pressure would read 0 psi.
You can probably read the fuel rail pressure also. Expect to see somewhere around 5K psi at idle all the way up to 25K under load acceleration.
There must be a lag with posting. Just saw your latest post, the fuel pressure would be 11K-12K while cruising. You would want to see how high it climbs while under load, it should easily push 20K psi climbing a hill with a load

 

[dirtbys]

so the OBD II reader i have does have the option to read Intake Manifold Absolute Pressure if thats the same thing. Not sure if the ECM provides a input though. I will have take it for another test drive and check that. Fuel rail pressure was in that range as noted above. I will check out that app as well. Thank you.

 

[crash68]

That manifold absolute pressure should be the boost pressure plus the 14.7 psi,
At idle you'll see about 0 psi of boost, if it registers about 15 then you need to subtract that to know boost pressure. Normal driving expect to see 5-15 psi of boost, while towing/under acceleration you'll be 15-30 psi.

 

[dirtbys]

ok cool i downloaded the app so i will check that tomoro to see if it will connect to my code reader. also was thinking i could just remove the condensor for now since i am in Alaska and wont need A/C for awhile yet and see how that goes. See if it still overheats. Figure i can temporarily just cover the ends of the A/C lines for now. The system is empty anyway since i put a new compressor on last fall and havnt gotten it recharged yet.

 

[dirtbys]

so the fusion app doesnt work with my code reader but mine has its own app which tells me the TAP and gives me barometric prssr as well which was 29 on my way to work this morning. anyone have any thoughts on me just pulling the condenser for now?? would that cause any issues?