Recently I towed our 5500 - 6000 lb camper with our 1996 K2500 Suburban 7.4, with 4.10 gears and a 4L80e trans; once to the mountains in NC, the other to the camper dealer near Richmond.
Towing speed on both trips averaged 65 mph or below, in 3rd gear, as advised by the shop that recently rebuilt the transmission.
On the trip to the mountains, coolant temp stayed just below 210º, and maybe a bit more a couple of times. Air temperatures were mostly in the high 60s and low 70s. On the trip to Richmond, air temp was around 87º, and the coolant temps hung around 216º, and got up to 225º indicated, and confirmed by an OBD2 dongle.
We have a couple of upcoming trips in June and July to the mountains in VA, and the air temps could easily get into the 90s at lower elevations. The question is what is the acceptable coolant temperature range for the 7.4L while towing? The highest I’ve seen it go is 225º, and that was in rolling terrain on the interstate.
Maybe I just missed it, but searching through the GM SM I couldn’t locate a definitive “normal” coolant temperature range; nor could I find a temperature at which the engine is considered to be overheating.
Can anyone here shed some light on this?
Towing speed on both trips averaged 65 mph or below, in 3rd gear, as advised by the shop that recently rebuilt the transmission.
On the trip to the mountains, coolant temp stayed just below 210º, and maybe a bit more a couple of times. Air temperatures were mostly in the high 60s and low 70s. On the trip to Richmond, air temp was around 87º, and the coolant temps hung around 216º, and got up to 225º indicated, and confirmed by an OBD2 dongle.
We have a couple of upcoming trips in June and July to the mountains in VA, and the air temps could easily get into the 90s at lower elevations. The question is what is the acceptable coolant temperature range for the 7.4L while towing? The highest I’ve seen it go is 225º, and that was in rolling terrain on the interstate.
Maybe I just missed it, but searching through the GM SM I couldn’t locate a definitive “normal” coolant temperature range; nor could I find a temperature at which the engine is considered to be overheating.
Can anyone here shed some light on this?