Low Coolant / shut off engine

After the two coolant lines on back of engine broke , had to keep starting the truck , running until it was shutting down. Obviously not low on coolant as filled up. When it got 200 degrees it would stop doing it. Figured it was a air pocket on the back temp sensor or something.
Well left Arkansas at came to Kansas. Next day Idling and the low light starts flashing and then after a bit the stop engine.
Odd thing is I can start driving and light goes out. But if sit at a light it will come on again.
Also I dropped trailer and bobtailed 10 miles or so. Did not do it while dropping or after letting it idle at home.
Had a lack of power also when pulling loaded trailer.

And to top it all off, the retainer clips fell off the s cam on trailer ,opposite side as a few weeks ago. Just had brakes , bushings done a few days before.
Fun fun fun.

 

Depending on the year truck there could be a sensor in the coolant tank
When you move it recognizes the coolant level
Could be a faulty sensor??

My previous truck would do that once in awhile and a friend who had the same truck said his did it a lot

 

My Trucks been plagued with this problem since I got it. I changed sensors a few times. Each time I thought it was fixed. Finally changed the pigtail, buying a new one, that’s about 10” long. A mechanic told me they often break along the intake. I think the plug goes bad also from vibration. Every time the fan kicks on, it flops around. Some good zip ties helps. Last time it happened it would shutdown when wet, I’d unplug it, then shut down again once it dried out. Plug it in till it rained hard or got washed. It’s been a couple yrs ago, I replaced the harness again. Turned out to be the sensor this time. Lol. It has literally driven me nuts over the years. Depending on your Truck, you can usually unplug it, may or may not need to jump the plug with a paper clip, to make it run, or turn the yellow cel warning light off. Worst case scenario is cutting the harness and twisting wires together. To keep from needing a tow truck. Usually if you jump the plug with a paper clip and problems solved, it’s the sensor. Being intermittent though, it can be frustrating. You can sometimes Change the sensor quickly without losing much coolant,

 

Mark,

The 579 will have issues with the float in the plastic surge tank. If you continue to have issues with low coolant warning even when the tank is full, the issue is likely a stuck or sinking float inside the surge tank.

I'm not sure why but losing the coolant from the tank can aggravate this. Occasionally when we perform a cooling system repair, they will act up and never straighten out until the tank is replaced.

 

The 2019 Pete I drove would throw a low coolant code going downhill then immediately go off at the bottom. Truck did that for first 60,000 miles and out of the blue quit doing it .

 

579 Pete / 3 wire plug. When that sensor went bad I could start truck and move about 10 feet before the engine shut off.
Thinking this may be an air bubble problem. Somewhere I lost 1/2 g coolant, found no drips. Filled it up. drove about 25 miles. Idled a few minutes and the light came on. Coolant tank had lots of pressure. Completely fulll. I opened cap and let it idle . Never shut off. Think that fixed it but tank is still completely full. But no light on.

 

What a fun reading meaningless post, no truck year, make, engine, nothing.. just pour some liquid into it, it should be fine.

 

Makes sense it’s just air pockets. No problem before it went low. It can take a long time idling with the cap off to get rid of them. Sometimes there’s a Petcock vent on the top hose, opening it up helps. After an inframe, and a new radiator, it took Me almost 3 hrs. to get it filled properly.

 

QUOTE="Goodysnap, post: 11709500, member: 200878"]Mark,

The 579 will have issues with the float in the plastic surge tank. If you continue to have issues with low coolant warning even when the tank is full, the issue is likely a stuck or sinking float inside the surge tank.

I'm not sure why but losing the coolant from the tank can aggravate this. Occasionally when we perform a cooling system repair, they will act up and never straighten out until the tank is replaced.[/QUOTE]
When my thermostat went bad , Kenworth fixed it. I left Joplin and went about 20 miles and parked. In morning when I started up, the coolant tank sensor had went bad. the first thing mechanic told e to do was check that float to see if it went bad because of servicing.

 

I spaced out and forgot to put the that in.
17 Pete 579 mx13.