wfstewa Report post Posted March 28, 2018 I have a 2008 Tiffin Phaeton with the Cummins ISC 360 HP engine. As I was approaching my present destination, a "check engine, coolant warning" amber light came on. It went on and off as I traveled the last 10 miles or so to my destination. On checking the coolant levels after the engine had cooled, I found that the "surge" tank was filled to the proper level between min and max. Also, while the warning light was coming on the temperature gauge and the oil pressure gauge remained at normal levels. A couple of years ago, I had the cooling system flushed and refreshed at a freightliner service facility. Any ideas about why I am getting these warning lights will be appreciated. Share this post Link to post Share on other sites
manholt Report post Posted March 28, 2018 Quote Coolant warning light. You have a bad sensor, it should be located on the surge tank about half way up. Disconnect the 2 wires and order a new one from Tiffin. Call Tiffin Tech and it will be sent to you, $40+/-. Mine was $38+ with shipping. When you replace it, use a clean gallon bowel, unscrew old, insert new and reconnect wires, pour coolant back in tank. Share this post Link to post Share on other sites
kaypsmith Report post Posted March 28, 2018 2 hours ago, manholt said: use a clean gallon bowel Naughty, Carl! Try to not be so personal. Share this post Link to post Share on other sites
wfstewa Report post Posted March 28, 2018 Wow! Instant on target guidance. Thanks much. I appreciate it. Share this post Link to post Share on other sites
bhalldorson Report post Posted March 29, 2018 My experience with overheating. We have a Fleetwood Expedition on a Freightliner chassis with a Cummins 6.7 liter engine that we purchased new. Between 10K and 40K miles we chased an overheating problem that presented as coolant temperature and engine temperature trouble signals. In every instance we returned to the nearest Freightliner dealer in various parts of the U.S. During this time, sensors were replaced, fan clutch replaced, water pump replaced, thermostat replaced and the radiator steam cleaned without removal. Ultimately, a Cummins dealer in Phoenix diagnosed the problem as dirt and debris, between the radiator and charge air cooler. This was without hesitation and without inspection. While we relaxed in the motor home they removed the radiator and charge air cooler, then invited me to take photos of the two with caked dirt and grass that covered both surfaces. We like remote camp sites. After they were cleaned, the digital engine temperature display has never exceeded 202˚F regardless of the load, altitude or speed. Normal at cruise is 196. After every trip I make a point of hosing down the radiator and charge air cooler. Share this post Link to post Share on other sites
wildebill308 Report post Posted March 29, 2018 1 hour ago, bhalldorson said: My experience with overheating. We have a Fleetwood Expedition on a Freightliner chassis with a Cummins 6.7 liter engine that we purchased new. Between 10K and 40K miles we chased an overheating problem that presented as coolant temperature and engine temperature trouble signals. In every instance we returned to the nearest Freightliner dealer in various parts of the U.S. During this time, sensors were replaced, fan clutch replaced, water pump replaced, thermostat replaced and the radiator steam cleaned without removal. Ultimately, a Cummins dealer in Phoenix diagnosed the problem as dirt and debris, between the radiator and charge air cooler. This was without hesitation and without inspection. While we relaxed in the motor home they removed the radiator and charge air cooler, then invited me to take photos of the two with caked dirt and grass that covered both surfaces. We like remote camp sites. After they were cleaned, the digital engine temperature display has never exceeded 202˚F regardless of the load, altitude or speed. Normal at cruise is 196. After every trip I make a point of hosing down the radiator and charge air cooler. Yes it is a common problem with rear radiator coaches. It should be addressed at least yearly. wfstewa, I would look at yours to. Bill Share this post Link to post Share on other sites
manholt Report post Posted March 29, 2018 WBill. I do agree, that is a thing I do every time, I come home after my 7-10K summer trip! OP had no increase in Temp or loss of fluid. = Coolant sensor! Don't know where bhalldorson lives....but you and I live in the land of 2 seasons and June to October, it's well over a hundred in the shade with a fan on! Share this post Link to post Share on other sites
wildebill308 Report post Posted March 29, 2018 1 hour ago, manholt said: WBill. I do agree, that is a thing I do every time, I come home after my 7-10K summer trip! OP had no increase in Temp or loss of fluid. = Coolant sensor! Don't know where bhalldorson lives....but you and I live in the land of 2 seasons and June to October, it's well over a hundred in the shade with a fan on! It never hurts to add cleaning the CAC to your annual maintenance list. I hope to escape before it gets to hot. Bill Share this post Link to post Share on other sites
manholt Report post Posted March 29, 2018 Yea, me too. Going to Ruidoso, NM the 11th of June, but could be May 20 if the weather dictates it. Sincerely hope you and DW get to enjoy a full Summer in Main, this year! Share this post Link to post Share on other sites
