Coolant temp issues

[safn1949]

Oh... The smell of coolant might be a heater core issue staring. Mine didn't fail from corrosive coolant but the thin solder joint failed and was weeping on top of the HVAC box.

I don't get the smell but the windshield fogs up all the time,it's a real pain. I wondered if the heater core was the cause but I usually can smell even minute amounts of coolant.

[SNKEBIT]

I don't get the smell but the windshield fogs up all the time,it's a real pain. I wondered if the heater core was the cause but I usually can smell even minute amounts of coolant.

Heater core..............:banghead:

[AH64ID]

My napa 190 rides about 188, maybe 186 in the colder weather. If im cruising slower, then it runs closer to 180.

My Cummins 190° does the same. It was cold enough on my drive back from Seattle the other day that on shallow downhills I would run at 186° at 75 mph after running several hours. 180° seems to be the temp that it holds when fully closed at low load, such as idling, slow crawling, or coasting down a long hill. The swing is normal. The 190° thermostats crack at 190° ± 3°, and are not full open until 207°. Because of the over-sized cooling the radiator stays fairly cool/cold in the winter when your not towing so there is a rush of cold coolant into the block when the thermostat cracks, and it takes many mile of driving to stabilize the thermostat at the proper position to maintain temp, and then any power change will effect it. As the thermostats age they develop wear spots because they rarely go full open, in fact until I got my 8K lb TT my thermostat would only go full open a few times a year with my 4.5K lb TT, and that's with about 100rwhp over stock. The cooling system is WAY over-sized, and it's great. Anyways, the wear spots make them slower to react and reduce the ability to smoothly open. When I changed my OEM thermostat at 55K miles the difference was night and day. I went with a Cummins stat as I have heard of too many issues with non-Cummins ones. Anyways, as to running 180° on a 195° thermostat, how long had you been driving? I suppose it's possible that NAPA is rating the full open temp, not the crack temp like OEM does. The OEM 180° thermostat is full open at 198°.

[dave110]

My Cummins 190° does the same. It was cold enough on my drive back from Seattle the other day that on shallow downhills I would run at 186° at 75 mph after running several hours. 180° seems to be the temp that it holds when fully closed at low load, such as idling, slow crawling, or coasting down a long hill. The swing is normal. The 190° thermostats crack at 190° ± 3°, and are not full open until 207°. Because of the over-sized cooling the radiator stays fairly cool/cold in the winter when your not towing so there is a rush of cold coolant into the block when the thermostat cracks, and it takes many mile of driving to stabilize the thermostat at the proper position to maintain temp, and then any power change will effect it. As the thermostats age they develop wear spots because they rarely go full open, in fact until I got my 8K lb TT my thermostat would only go full open a few times a year with my 4.5K lb TT, and that's with about 100rwhp over stock. The cooling system is WAY over-sized, and it's great. Anyways, the wear spots make them slower to react and reduce the ability to smoothly open. When I changed my OEM thermostat at 55K miles the difference was night and day. I went with a Cummins stat as I have heard of too many issues with non-Cummins ones. Anyways, as to running 180° on a 195° thermostat, how long had you been driving? I suppose it's possible that NAPA is rating the full open temp, not the crack temp like OEM does. The OEM 180° thermostat is full open at 198°.

Thanks for the info. I drive mostly the same routes so I have a pretty good idea of what my temp should be at what location. Where it was normally at 190 I kept driving and 180ish was as hot as it got. The full open at 207 is great for me to know. Pulling my trailer the other day in some hilly terrain it would go to 207 and then fall off quickly to stabilize around 190. I guess I was just really lucky before with my Powerstroke and the stat I had in this truck. I've had it for 4 years now and it always was a steady 190. I might try a Cummins stat yet to see if I can get back to what I thought was normal. One things for sure. If I had circulation issues like I originally thought I would have melted it by now.