hot engine temps while towing

Fixit

Fixit

Well-Known Member
2004 gmc 1500...
towed a 4800kg load of wood back from kelowna yesterday and was running pretty hot coming up the long hills
(ie west bound leaving merrit) 40kph first gear 4000rpm. engine was running at 115 with peak temps around 120*c
ambiant air temps were about 29-32*C
my truck has the tow package with big trans pan, coolers etc...

is this a normal temp for hauling such a big load or is there something wrong w my truck?
 
My guess would be heat from the trans
Not up to speed with your particular model but many of the trans I have had don't allow lockup in 1st or 2nd so with a heavy load and no lockup in the converter your oil heading to the cooler ( rad ) can be wicked hot
I have seen temps of 280* in the output line ( best place to put temp gauge IMO ) until lockup and if sustained I have had h2o temps go up 20/30*
This is one of the reasons you see so many burndowns on killer hills like the coq
Trans fluid gets so hot it boils up the dipstick tube and spills out on hot exhaust manifolds
 
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4800kg is gnarly for a 4l60E. Treat it to a flush & filter change. I don't think there's a half tonne pickup out there from that era that's meant to tow that kind of weight.
 
Although it may not be at the required mileage, I would suggest you have the fluidd replaced. Should be around 150$ at your GM dealer and you will get the latest updated fluid. If you continue to haul heavy loads over the coq, than an external cooler may be in your future.
 
That's a pretty big load for your half tone, couple that with high ambient temp and your going to have issues. If you don't have an external cooler you should definitely look at putting one on.
 
Your gross combined is 12000lbs. You were probably over loaded by 2000+lbs.
Add a bigger trans cooler, make sure your trans oil is still red and not burnt smelling. If it was a ford you would be broken on the side of the road.
Like others have said do a trans service, and not just a pan dump (4L of oil) you want to change all the oil (about 12L of oil)
 
Is that #4800kg scaled weight or is that what the trailer is rated for. Seen lots of guys grabbing firewood and don't realize the weight they are putting on the truck, most are way over loaded. Willing to bet it's the trans.
 
trailer weighed in at 4600kg on the scales and i had 200kg more weight on the back axle.
trailer is 21k rated i believe, triple axle with electric brakes on every wheel. couldnt use the brakes on any setting above 3/10 as they were too strong

i already promised her an oil change and a wash, ill change the trans fluid too, although it didnt smell burnt on any of my stops

ive noticed that on occasion towing in lions bay (stupid steep) that it gets hot too... perhaps a cooler should be added to the list.
anyone have a favorate brand
 
I'll bet you were near smoking hot coming out of Peachland too, that hill must be one of the biggest engine killers in BC. From 350 m to 1750 m in 30 km is a relentless climb. Coming back from Kamloops yesterday evening I saw 5 or 6 vehicles overheated on the roadside.
 
Wow, that is quite a haul for your 1500. You have received lots of good advice. Really though you should be staying at least 10-15% under the max ratings to give yourself a cushion so I'd suggest taking a little weight off your loads.
 
I haul my boat from Kelowna to Vancouver Island over the Coq. Boat is about 5600 pounds loaded up. Tow vehicle is a Jeep Grand Cherokee. V8 HO.
It tows very well and I can keep up to about 90KM at 3500 rpm going up the steep parts. Could go faster but that seems to be its happy place. I have a trans cooler with tow package. It barely goes above normal operating temps. However I plan all my trips to leave early in the morning or come back later in the evening. Would never do it when 30C +. Especially when you can only do 40KM as not much air flowing over the rad.
My goal is for the temp to be 20C or less.
I am not as knowledgeable as some on this forum but sounds to me like that is way too much weight for your truck. You should have been able to go 80KM at least. That tow speed and first gear should tell you.
I think you need a new diesel truck. :)
 
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