Community Forums

namwob · 03-23-2010, 09:02 AM

The Low Engine Coolant Warning Light/Buzzer activates intermittetly on my 99 Cummins ISC. The alarm will stay on for a couple of minutes then go off for a while and then acivates again. A check of the reserve tank shows the level is okay and everything looks fine inside the rad when she's cooled down.

Note: this is the same problem Chonburiman had on 11/21/2008 and there didn't seem to be any resolution. (?)
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FleetMan · 03-23-2010, 09:13 AM

Low coolant sensors have been a common problem on Cummins engines. Don't be surprised if that is the problem.

namwob · 03-23-2010, 09:24 AM

Hmmm... I have also had my faulty Oil Pressure sensor replaced... That one caused the "Stop Engine" warning and automatically reduced engine power.

openpro · 03-25-2010, 08:09 PM

Glad to hear. My 2002 Journey 32t does the same thing with the low coolant light.

Greg121 · 03-29-2010, 08:07 AM

Me too, alarm activates a few seconds after start-up, stays on for a minute or so then goes off. I picked up somewhere, sometime that it may be crud accumulating on the sensor and to clean it off with a white scotch brite pad.

The alarm is irritating but as it has always turned off before I set out I haven't bothered to try cleaning the sensor yet. If someone does and it works let me know and maybe I'll get more motivated...thanks....

Greg, W5KJ
2000 Dynasty w 350 ISC

GaryKD · 03-29-2010, 04:26 PM

For those having a see through plastic expansion tank checking the coolant level is no problem. For those having a metal expansion tank with a small bulb sight glass it can get a little harder. For me, I do not depend on the sight glass. It has become coated on the inside and when I changed the coolant, it looked exactly like when the correct amount of coolant is in the tank. What I do is take a metal coat hanger and stick it in the tank. Upon withdrawal, I can tell exactly where the coolant level is.

namwob · 04-06-2010, 09:09 PM

Does anyone know where the coolant sensor is located?

a k · 04-07-2010, 08:36 AM

Mines screwed into the bottom third of the expansion tank(The one with the radiator cap on it)

GaryKD · 04-08-2010, 03:27 PM

Mine is the same as a k. It is the lower part of the expansion tank.

HD4Mark · 04-08-2010, 03:40 PM

My low water light also comes on occasionally when first starting. At first I dutifully checked the level only to find it full. Now I give it a minute and it goes out. I check the level often anyway because I am paranoid about these things

Does anyone else with a plastic tank find it so faded that you can not check the level by looking at it? At night I shine a flashlight behind it but in daylight I have to wait for it to cool and stick my finger in the fill opening on the side.

FW · 04-09-2010, 10:59 AM

My 2000 Diplomat did the same thing. My diesel man told me to just put in an extra pint of distilled water. I did that and haven't had any more alarming.

a k · 04-10-2010, 04:15 PM

See if this will help you out.

OK here's the one. If not let me know what you need.

namwob · 04-10-2010, 10:04 PM

a k

Thank you!

ThePips · 04-20-2010, 12:00 PM

Our Knight started showing an occasional low coolant light and, like everyone else, it would go out after a while. Gradually it got worse and worse until it wouldn't go out at all. I finally couldn't bear it any more, constantly worrying if maybe it WAS low on coolant and I'd find out the hard way. It wasn't enormously expensive and I feel a lot better knowing an alert is genuine.

Regards
Doug