Community Forums

Navy Flier · 09-06-2008, 06:38 PM

Picked up my new coach from the dealer Friday after they completed the punch list. Home is about 20 miles. All normal until about one mile from home the check engine light comes on followed fairly quickly by the stop engine light and "hot coolant" message. Pulled into the driveway and shut it down. After two hours went out and started the coach to put it in the garage. On start up the temp was down to "normal" so I put it away. Today I started the coach and let it run at high idle. After about 15 minutes the temp stabilized at 180. The only thing I had noted previously was the temp gauge stabilized at about two needle widths above half way and I am used to seeing temp just below half way on other engines. When it indicated hot the coolant level was normal but I did note that water had been spitting out of the overflow tube. I did not notice the temp climbing on Friday as the last eight miles are on narrow hilly roads that require full attention.

Navy Flier · 09-06-2008, 06:38 PM

Picked up my new coach from the dealer Friday after they completed the punch list. Home is about 20 miles. All normal until about one mile from home the check engine light comes on followed fairly quickly by the stop engine light and "hot coolant" message. Pulled into the driveway and shut it down. After two hours went out and started the coach to put it in the garage. On start up the temp was down to "normal" so I put it away. Today I started the coach and let it run at high idle. After about 15 minutes the temp stabilized at 180. The only thing I had noted previously was the temp gauge stabilized at about two needle widths above half way and I am used to seeing temp just below half way on other engines. When it indicated hot the coolant level was normal but I did note that water had been spitting out of the overflow tube. I did not notice the temp climbing on Friday as the last eight miles are on narrow hilly roads that require full attention.

GaryKD · 09-07-2008, 02:48 AM

Hi Navy Flier,
Because the coach is new, there could still be air in the cooling system, or the dealer may not have checked the coolant level before delivery. A cheap and easy way to determine if you have the correct amount of coolant is:

When the engine is cold, get a rod and use it to determine the real coolant level by inserting it in the overflow tank. Do not use the sight glass, but the measurement taken with the rod. If the coolant level is low, add the appropriate amount of coolant to raise the level above the sight glass.

Techie · 09-07-2008, 08:34 AM

FWIW I always keep enough coolant so that the sight glass is up to the 1/4 - 1/3 mark.

At full operating temp I've never seen it get above the 3/4 mark on ours.

Navy Flier · 09-07-2008, 07:36 PM

I do not have a sight glass on my coach. The overflow tank is above the radiator and easy to see. When it was hot the overflow tank was almost full and when it is cool the coolant is at the "max when cool" line.

chasfm11 · 09-08-2008, 03:39 AM

Several of us use VMSpc, a computer program with an interface to the chassis wiring that allows us to see exactly what is happening on the chassis messaging rather than relying only on the information in the gauges

The reason that I mention this is that I did a complete engine coolant flush and replacement along with all of the hoses in June. Watching VMSpc afterwards, I can see the coolant temperature change from the normal 183 degrees as it cycles up to 194 when my thermostat kicks up. The coolant temperature than returns to 183. All this while the needle on the temperature gauge barely moves. If you could see a similar cycle on your ISL, you would know whether the thermostat was opening properly. As suggested, you may have air in your system. On my ISB, there is a petcock above the radiator that can help bleed off the air but it will quickly pump coolant if the engine is running. The refill procedures on mine recommends opening the petcock and allowing some coolant to escape as a way of helping to remove air.

I had to add coolant a couple of times after my change as the air worked its way through the system. The engine ran a few degrees hotter initially than after I added that coolant. On a recent 4,400 mile trip, the coolant temperature never varied from the 183-194 cycle that I described, regardless of the engine load.

Navy Flier · 09-08-2008, 12:26 PM

Chasfm11 thanks for the air bleed thought. I also have a computer display system that allows me to see the engine temps/pressures.

GaryKD · 09-08-2008, 02:32 PM

Because your coolant level is okay. I'd say the engine is acting normally. My ISC is rock solid at about 180; unless I climb a long and steep grade. Downshifting helps, but the ISC temp will get to 220. Once over the hill it quickly returns to around 180. 180 on my temp guage is at 1 oclock, well past the 1/2 way mark.

Enjoy your new coach and may you have many happy memories.

Spikester · 09-08-2008, 06:15 PM

Agree with Gary, sounds like an air burp in your cooling system. The coolant level on my 2008 ISB did not stabilize until it had about 5K miles on it. Do not have overflow tank, but system kept burping coolant out the overflow tube, Cummins checked out system to no avail, told me it was just air working its way out of the system.

Select your coolant temp on your electronic readout so you can see the actual temp fluctuations. Your new low emission engine will run a bit hotter than previous ISL's. Also your Cummins operator manual will give you your min, normal and max operating temperatures.

Spike

Soniccruzer · 11-12-2008, 06:41 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by chasfm11:
Several of us use VMSpc, a computer program with an interface to the chassis wiring that allows us to see exactly what is happening on the chassis messaging rather than relying only on the information in the gauges

The reason that I mention this is that I did a complete engine coolant flush and replacement along with all of the hoses in June. Watching VMSpc afterwards, I can see the coolant temperature change from the normal 183 degrees as it cycles up to 194 when my thermostat kicks up. The coolant temperature than returns to 183. All this while the needle on the temperature gauge barely moves. If you could see a similar cycle on your ISL, you would know whether the thermostat was opening properly. As suggested, you may have air in your system. On my ISB, there is a petcock above the radiator that can help bleed off the air but it will quickly pump coolant if the engine is running. The refill procedures on mine recommends opening the petcock and allowing some coolant to escape as a way of helping to remove air.

I had to add coolant a couple of times after my change as the air worked its way through the system. The engine ran a few degrees hotter initially than after I added that coolant. On a recent 4,400 mile trip, the coolant temperature never varied from the 183-194 cycle that I described, regardless of the engine load. </div></BLOCKQUOTE>

Chasfm11,

I have a pre-emissions ISL 400 and the coolant temp also varies between 194-204 every 30 seconds. I'm told this is normal, but my question is should the hydraulic fan ramps up t every 30 seconds when the temp reaches 204. I can hear this while driving and it gets old after a long day of driving.

Any Ideas

RickO · 12-18-2008, 01:27 PM

Add me to the list of new owners who had problems due to low coolant. On my maiden voyage, the STOP ENGINE light came on while headed up the grapevine near LA. Coachnet had it towed 40 miles to a Cummins dealer in Bakersfield who simply added coolant and said it had been a problem on new coaches lately.

Grrrrr.... I'm saving up for the VMSpc.