Overheating need help

[Ozymandias]

Put a new thermostat* in it and a new Radiator cap. And check the belt routing.
Then we can start diagnostics why it is going hot.

*thermostat spring points downward, that's the orientation how I needs to be in there.

 

[MPieper]

Yes they are.

 

[brucejohnson]

It initially sounds like you were experiencing an overheat condition prior to changing out the parts listed. (Assumption derived from initial post)
If so, that would eliminate several possibilities to look at, barring faulty new parts.
The IR thermometer would be one of the best tools to follow the heat path. "Calibrated" hand touch works but moving parts prevents safe access to some places.
When starting cold, does the upper hose begin getting warm as the thermostat opens? Block around thermostat housing should warm up, then heat up quickly when the t-stat opens. The upper hose temp increases. The radiator is large, but usually with the cap off you may detect flow which will warm up quickly. The lower should stay relatively cool until the flow through the radiator begins.
One often overlooked issue causing an overheat condition is a collapse lower radiator hose. Many of them have a spring inserted to prevent the hose from collapsing. Others are designed with a more rigid casing. Cheap hoses have neither.
The heater core should heat up which can be determined by turning the heat up all the way with the fan blowing.
Some of the simpler causes when changing parts out are routing the serpentine belt improperly causing the water pump to run in reverse. Not sure if that can happen on the Cummins, but Murphy has a way to mess things up when least expected.
Another issue is a loose and/or poorly designed impeller on the water pump. My son had that issue. It came from a large auto parts store - and went right back for refund. I gave him a quick lesson on which "MoPar" parts he SHOULD use and how to confirm serviceability BEFORE the pump is installed. Lessons learned.
A faulty water temperature sending unit, causing unreliable signals fed to control circuits. I have had several vehicles where the A/C cut out when a high water temp was sensed. It would seem the electric fan clutch would be signaled to the fan roar mode as the heat indication increased. ECM may be suspect.
Ozy's Posts are great, as well as AH64ID , Darkbloodmon's, and everybody else who responded. (I see they beat me to the button on most of these)
A head gasket was mentioned. How does your oil look/smell? Frothy grey/white, sweet antifreeze? Any odd bubbling noted with the radiator cap off? White steam/smoke from the tailpipe?
Oil sample to be analyzed for wear elements? Something became "tight" internally creating friction.
Transmission temperature? Slipping?
So many things to address.

 

[MPieper]

I will bring the tep gun and ck it tomorrow. As mentioned previouslyvI did remove the thermostat to rule that out a a potential issue. Napa did not even stock the temp sensor told me they sell very few. I could replace it but did unplug it and temp indicated was in the red. Reconnected and back to reading about 200. Nothing unusual with the oil. The oil no white smoke and no loss of antifreeze unless overheated and overflow is full

 

[AH64ID]

Yes they are.

My experience with lifetime warranty parts is that you spend a lifetime replacing them because they are subpar, I would be surprised if you got a bad radiator out of the box.

 

[MPieper]

What could I do to see if it is bad? Doesn't leak or have any visible signs of being bad

 

[AH64ID]

What could I do to see if it is bad? Doesn't leak or have any visible signs of being bad

The overheating is a sign something is wrong. Could be a plugged radiator.

 

[Ozymandias]

Change that rad. Cap, it is a wear item and needs replacement every couple years.

 

[MPieper]

Radiator cspbis new as well came with the new Radiator .

 

[Ozymandias]

If your cap is good why does it boil at 210 then?

 

[brucejohnson]

Have you pressure checked the cooling system and cap?

 

[brucejohnson]

Removed the thermostat and drove today. Still getting hot just before the red. Fan runs when cooling for the ac but stops when past 200. Then ac compressor begins to cycle very frequently and fan is not running. Problem has to be in the control of the fan which seems to be only from the ecm.

You stated the system worked for a couple of weeks. So something must have happened.
I assume you keep the A/C on at all times. (I do)

What happens with the cooling fan when you turn off the A/C after starting the truck? Fan controller appears to be inop in the normal mode, but functions with the A/C until an overheat condition? (A/C shuts down when overheat detected in order to assist in faster cooldown in many vehicles, as well as transmission limitations)

Does the fan run and/or change speeds as the engine warms up and when it is driven at normal temperatures?

The temp switch appears to be working. When you disconnect the plug on the temp sender it opens the circuit and causes the gauge to indicate hot. Plugged back in all appears normal until the engine overheats and the gauge indicated hot. So temp sender appears to function properly. (Bubbling coolant recovery suggests it is definitely hot)

The thermostat removed and still overheats. Flow impedance? Fan operation?

Heats up coming off the highway? Air reduction through the radiator fins by slowing down. Fan controller? Inadequate radiator, water pump? How many rows and fin count? Slower water pump flow through an impeded cooling system? Check the lower radiator hose for firmness and if it has an anti-collapse spring properly positioned in the hose. (when hot, rev up the engine several times to create a draw from the water pump while observing the lower hose)

So far suspected by presented symptoms =
ECM and related fan controller circuit/plugs and/or something impeding flow (hose/radiator/pump) and/or cooling system pressure issue (low boiling point).
Less likely, internal friction, cylinders, rings, bearings.

The bubbling coolant in the recovery tank jarred a memory cell. Back in the mid 80's I was looking at a used Oldsmobile station wagon which was diesel powered. On the test drive everything was going well, until it reached operating temperature, when the hot light came on. Checking under the hood the coolant bottle was "boiling" violently while the engine was running. Turned engine off, and slowly ceased bubbling. Back on, and Fizzies galore (showing my age). The infamous head gasket on those GM diesel Wanna-Be's. No sale that day.

 

[Ozymandias]

https://www.google.com/search?q=check head gasket test&ie=utf-8&oe=utf-8&client=firefox-b-1-m

 

[CharlesinGA]

Removed the thermostat and drove today. Still getting hot just before the red. Fan runs when cooling for the ac but stops when past 200. Then ac compressor begins to cycle very frequently and fan is not running. Problem has to be in the control of the fan which seems to be only from the ecm.

I'm wondering how you simply removed the thermostat and refilled it and ran it, without it leaking. The only seal for the thermostat housing is the seal on the outer edge of the thermostat. That is why I took my original thermostat and cut the supports and took the guts out of it to flush the cooling system (had unknown green coolant in it when I bought it). Against better judgment I bought a NAPA thermostat and installed it. Ran somewhat hotter and after a year or so began sticking. Nary a problem with a new Cummins thermostat and runs right where the original thermostat kept it.

I don't understand how you got it to not leak with thermostat removed.

My initial impression is someone, somehow mis routed the belt but I have no idea how you would do that and get it to work. You would have to have the grooved side running on the smooth fan pulley. Have you looked at the wires going to the fan to make sure they were routed properly and not chewed up by the fan?

Charles

 

[CharlesinGA]

Oh, and the temp gauge at the cluster is fake anyways.
It shows nicely around the middle range - until it really boils, then finally it virtually jumps into the red are.
Real water temp is only accessible through a scanner.

I do not buy that. On the oil pressure, I understand that the engine has a simple on/off switch and then moves the gauge based on other parameters. The temp sensor however, is a simple metal variable resistance based on temperature like any other vehicle and engine temp responds to temp changes instantly, such as when my thermostat stuck temp quickly rose, and as soon as it unstuck, it dropped back to normal. Kits such as the BD Howler turbo kit look at engine temp and do this by simply tapping into the wires right at the temp sensor, it it were not a real sensor, they would not be able to do that. I drove 15 miles this evening to refuel the truck and get something to eat and then back home, its so cool out after the storms passed (72 or so) that the engine temp did not even get up to normal and I doubt the thermostat opened at all. Fake gauge would not know this.

Charles

 

[CharlesinGA]

Shouldn't have an issue with an air pocket on a 3rd gen 5.9 as the radiator is higher than the engine T-stat, I changed 2 water pumps and the radiator on my 04 and never touched the thermostat, just re-filled via the coolant tank, filled the recovery tank and went for a ride.. then level off the recovery tank and done.. It sounds like there is an issue as has been said with the T-stat, and / or there was a blockage of the bypass in the old T-stat.

I just finished a radiator replacement, and it took fewer hot/cold cycles this time than in the past. I was not keeping good count but I think I ran it thru about eight or ten drive cycles before the coolant level in the overflow tank settled out. It is very stable now, as the last three or so times I have driven it, the next morning, the level was perfectly at the middle of the MAX marking on the overflow bottle. Will checkit again tomorrow morning. In the past when I flushed and serviced the cooling system it took about 20 or so hot/cold cycles for the coolant level to stabilize perfectly.

Charles

 

[MPieper]

Did a temp check on the radiator today with a temp gun. The difference at the top to the bottom hose was 5 degrees. The belt is on correctly. I got the thermostat housing to seal by just using the gasket.

 

[Ozymandias]

I do not buy that. On the oil pressure, I understand that the engine has a simple on/off switch and then moves the gauge based on other parameters. The temp sensor however, is a simple metal variable resistance based on temperature like any other vehicle and engine temp responds to temp changes instantly, such as when my thermostat stuck temp quickly rose, and as soon as it unstuck, it dropped back to normal. Kits such as the BD Howler turbo kit look at engine temp and do this by simply tapping into the wires right at the temp sensor, it it were not a real sensor, they would not be able to do that. I drove 15 miles this evening to refuel the truck and get something to eat and then back home, its so cool out after the storms passed (72 or so) that the engine temp did not even get up to normal and I doubt the thermostat opened at all. Fake gauge would not know this.

Charles

This is how mine acts, I could follow this nicely with the broken fan.
Sensor and dash aren't hard wired, the dash gets the Info through the BUS and shows what it is programmed to show. That's why you can see real temp through the OBD2 port.

https://mbworld.org/forums/e-class-w212/819458-so-engine-coolant-gauge-kinda-liar.html

Don't forget, our trucks are DC trucks.

If you want to learn more about this topic just Google for "dummy coolant gauge"

 

[brucejohnson]

W

Did a temp check on the radiator today with a temp gun. The difference at the top to the bottom hose was 5 degrees. The belt is on correctly. I got the thermostat housing to seal by just using the gasket.

as this running at idle or quick trip arond the block?
It would be nice to see values when the truck is overheating. Upper hose, lower hose, several points on the radiator, block, etc..

 

[CharlesinGA]

Feeding thru the bus and not being "real" are two different things. The bus is there to distribute the same information to several different places at once.

Actually, the temp sensor is connected directly to the ECM, the ECM then makes the information available to other components that need that information. I don't find anything in my '03 Shop manuals that gives me a clue that Dodge monkeys with the temp signals.

What you linked to is Mother Benz, and yes, they do some weird things. Even the Sprinter fuel gauge is fake information, based on miles driven, engine RPM, etc, and can be changed, via a dealer software switch, to read directly from the sender. This is on '07 and up Sprinters. Thankfully, my '06 Sprinter cab/chassis under my motor home was directly wired tank to the gauge.

My temp gauge works smoothly and steadily. When the thermostat stuck, it simply kept climbing, until the fan kicked in full blast which really didn't help, but then it unstuck and the temp dropped back and then the fan slowed down.

The first two post of this thread, https://www.turbodieselregister.com/threads/dash-gauge-summary-accuracy.258630/ are in reference to fourth gen trucks but seem to confirm my suspicions.

Charles