Gradual overheating issue

jmester

jmester

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Feb 28, 2015
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Have a 12v aftercooled 5.9 in a chipper. I have replaced the water pump do to bearing play. New belt and tensioner, new hoses and coolant. It has a direct drive fan. Re cored the radiator and went from a 4 row to a 5 row. I have put in 2 two new 180* Cummins termostats. I also have two temp gauges one at the front of the head and one at the back of the head.

It will come up to temp fine then gradually build more heat till it shuts down do to the Murphy switchgage @210. It takes about an hour for it to overheat and shut down. Leave it shutdown for about 10-15 mins then it will run for about another hour before it does it again. I have flushed it several times and it has good flow from everywhere. It does not push out coolant,use coolant or have coolant in the oil. Did a combustion gas test on it 3 times and it passed every time. Pulled the oil cooler tonite hoping to find it clogged up but it was not. Hope someone here can shed a different light. So I can get it figured out. Sorry it such a long post but want you to have the back story. Thanks
 
P3000 factory timing as far as I know is 15.5* at least that is what the data plate says
 
I'd check timing and pressure wash the radiator real good to start with.
 
Did this all start when you replaced the water pump, or were you already chasing the problem?

Have you verified it's actually getting that hot, maybe a wiring/sensor issue?

Did you own the machine last summer and it worked just fine?

Silly question, fan spinning the correct way and no obstructions in front of the radiator?
 
smokinVE said:
Did this all start when you replaced the water pump, or were you already chasing the problem?

Have you verified it's actually getting that hot, maybe a wiring/sensor issue?

Did you own the machine last summer and it worked just fine?

Silly question, fan spinning the correct way and no obstructions in front of the radiator?
Click to expand...
Good catch.
There are a couple different styles of water pump and that engine most likely had the 190 stat from the start.
 
Just bought the machine in March. New radiator core has less then 7 hrs of run time on it. I cant say I know if changing the pump helped or hurt. The water pump I took off the fan was not shielded and the new pump is shielded. I have read that the shielded pump flows more water. I asked Cummins tech yesterday about the water pump and he said it was just the updated pump. I have 2 mechanical temp gauges in it one at the front and one at the back of the head both read within 5* of each other. All parts are OE Cummins. The 180 t stat is what quick serve calls for and what I pulled out of it. I will check the timing after work today. I will only beable to check it from the timing pins in the pump and front cover. Thank you.
 
The fan is a sucker fan and it will hold a piece of cardboard tight enough that you have to forcefully remove it.
 
I always thought the open finned pumps would flow more. Seen a few in pusher style motor homes.
 
jmester said:
The fan is a sucker fan and it will hold a piece of cardboard tight enough that you have to forcefully remove it.
Click to expand...

That's not saying much. Does it have a shroud? That makes a surprisingly big difference. Also, the OEM fans leave a lot to be desired, you could start with just a fan swap. I know with my truck and my lower stall converter, it keeps a small load on the engine and if I'm using it for low speed stuff (<5mph) it'll very slowly rise in temp to a point (maybe 200F or so).

If you've got a spare t-stat around, you could drill an 1/8" hole in the side of it to see if it's a flow issue. The Cummins ones typically flow well, but the last two I've had worked worse than the Stant 45479 (195deg), which is what I run now and am very happy with it. Plus it's only $8 instead of $50.
Stant 45479 (195deg) next to stock 1997 12V Cummins (180deg) T-Stat - Album on Imgur
 
Yes the fan has a shroud. I thought about switching to a pusher fan but I have heard that they move less air. Remember this is a stationary piece of equipment no air is being force through. It just does not make sense a buddy has the same engine,fan and radiator in his chipper and he runs right around 180 to 190 I will try and check timing tonight.
 
Exhaust restricted? Mouse nest/damaged pipe/muffler falling apart/sooted up?

Sent from my SM-G935W8 using Tapatalk
 
210 isn't that bad if it's just y'all working it hard while it's hot outside. You ought to unhook the safety sensor and watch it close to see how much higher it goes. 215 max I say keep running it.
 
New manifold. Cummins rebuilt hx35w. 4" 90 to 18" chrome tip. I replaced the hose the goes from the turbo to the aftercooler. Once I get the oil cooler back on I will use some soapy water in a spray bottle and see if there are any boost leaks. I am to the point now of doing just like you said disconnect the shut down and run it and just watch and see if the temp keeps climbing or levels out @210 or so.
 
Sorry it has taken so long. I ended up pulling the oil cooler to make sure it was not clogged up. It was nice and clean with no blockage. Then went on to set the timing pin in the front cover to adjust the valves. Then found the timing pin was broken. Got a new timing pin. Adjusted the valves. Then on to checking the pump timing pulled the cap on the pump and no timing pin. So I got one. Found the the pump was indeed out of time. Reset the pump timing today. Has a more crisp acceleration and the smoke cleaned up a bit. I did not have much time to run it today should know more Monday as I need it on a job.
 
I ran it yesterday for most of the day. It runs better with the timing reset. Still runs at 200* on the front gauge near the termo stat and 190* at the back of the head. But it holds temp and does not keep climbing. So I think that just may have fix the issue. Thanks for the help.
 
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