5.3 overheats when going up mountains. Any ideas?
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Overflow tank is very important. If it's venting the coolant out on the ground then it's gone for good. It can suck the coolant back in from the overflow after it cools off.
High speed overheating can be caused by air pressurizing the back of the radiator. If the back of the radiator has almost the same pressure as the front, air doesn't flow through it. It can remove enough heat on flat ground, but can't remove any additional heat and thinner air at altitude removes less heat.
If the radiator isn't new, get a new radiator
extend the height of the core support air dam to at least 4 inches (the taller, the better)
Dual electric fans from an LS1 or Chrysler LH/300M
180 or 160 degree thermostat, depending on where you live.
With the above it won't overheat pulling up any mountain with the A/C on.
If the radiator isn't new, get a new radiator
extend the height of the core support air dam to at least 4 inches (the taller, the better)
Dual electric fans from an LS1 or Chrysler LH/300M
180 or 160 degree thermostat, depending on where you live.
With the above it won't overheat pulling up any mountain with the A/C on.
If your engine is basically stock and has given you no trouble at lower altitude, there are a couple of other things you might want to look at. First is fuel mix. If the air fuel mixture is even a little lean, taking the vehicle to altitude can introduce overheating issues by leaning the mix even further. Check timing, air filter, fuel mix ratio.
Also remember that, once an engine coughs up a bunch of coolant from overheating, adding water/coolant back to the system may trap air inside the engine. This may keep the engine over heating even if the original source of the problem is corrected.
You might want to increase the octane of the gas you run while up at altitude. It may help some.
Also remember that, once an engine coughs up a bunch of coolant from overheating, adding water/coolant back to the system may trap air inside the engine. This may keep the engine over heating even if the original source of the problem is corrected.
You might want to increase the octane of the gas you run while up at altitude. It may help some.
Here are some photos of my setup. One thing I was concerned about, was the T that’s shown in the photos. Not sure if it’s allowing the right flow. Again, I’m only overheating going up super steep inclines. The only thing is, we didn’t overheat going over Monarch Pass in Colorado, but I think I took that one a lot slower. The fan is a single fan unit as you can see and its from a ford. As far as the radiator, I’m not exactly sure. It’s a new aftermarket unit but not sure for what car. It’s been a couple of years since I purchased this set up. The thermostat is whatever’s factory for a 2005 Silverado. 187, 190 degrees?
I drove the car around town as a daily but of course we don’t have the inclines. Going to find a different overflow tank, drain and refill fluids and see how it goes.
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What turns the fan on? Does it spin the right way? It should make a lot of noise when running and blow hot air, but should not even come on just driving down the road. A fan like that should need a 30-40 Amp relay to start.
My Yukon XL overheated going over Engineer pass is Colorado, but I think it was air in the system from climbing combined with the altitude. Switching from a 195 to a 160 degree thermostat pretty much made overheating a thing of the past. Heated seats keep the driver warm when it is below zero, because the heater won't.
My Yukon XL overheated going over Engineer pass is Colorado, but I think it was air in the system from climbing combined with the altitude. Switching from a 195 to a 160 degree thermostat pretty much made overheating a thing of the past. Heated seats keep the driver warm when it is below zero, because the heater won't.
The fans come on when the Ac is on or when it gets to a certain temp. It's set up with a relay. The fans do not come on as soon as I turn the car on. I also thought about getting a different thermostat. When overheating, the system did act like there was an air pocket, sort of like burping the old northstar motors after attending coolant issues. When you overheated, did you lose a lot of coolant? I didnt realize how much coolant these motors take.
I lost about a gallon of coolant, maybe a little more. We were 11,000 foot up on the side of a mountain and had to hike down multiple times to a stream about 100 feet below the road to fill up water bottles.
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