Mudfly Posted August 24, 2020 Share Posted August 24, 2020 Asking for a little help from the forum. The wife, 3 kids and I are returning to the lower 48 after a few years of military service (wife is active duty AF). Made it to the border tonight north of Great Falls MT (didn’t have a choice, that’s where the Canadians sent us) and Truck started to overheat just south of Shelby, MT. I looked it along to Conrad. I sent the wife and Kids on in the car to friends in Helena. I am requesting 2 things if anyone is able to help. 1. I need thoughts on why it’s overheating. More details in the next post. 2. If anyone is in the area, or knows the area, I could use some thoughts on where to go for mechanic work. Otherwise I will just go to the dealer. (Ford dealer is town here). Much appreciated! 1 Quote Link to comment Share on other sites More sharing options...
Mudfly Posted August 24, 2020 Author Share Posted August 24, 2020 So the truck was doing awesome. It’s a 2001 Chevy 2500HD with the 8.1 liter and Allison at about 145,xxx miles. I’m pulling a 16 foot enclosed trailer with a lot of our stuff in it. Probably 6000 lbs plus. All was well, I was pulling a hill at 75 when I look down and the temp gauge is in the red. Got over to the side and got it cooled down. Had not gone over 200 Degrees for the previous 2400 miles (or ever for that matter). Now i can limp it along at 235 degrees on the flats at 45mph with the heater going wide open. Any little hill and the temps starts climbing right now. Any down hill or coasting will drop temp pretty quick to 200 ish. im thinking water pump since it happen quick, but I suppose it could be a head gasket also. Other thoughts are thermostat. Maybe related maybe not, the fuel pump sounds a little rattly. It doesn’t seem to be struggling to get fuel though. Any other thoughts? I’m staying here tonight and will check in with the ford dealer in town in the morning. It was too hot to check a lot of things tonight, but it has coolant in the overfill. No puddles on the ground. Belts looked tight, fan was spinning. No real strange noises or squealing. Quote Link to comment Share on other sites More sharing options...
Steve C. Posted August 24, 2020 Share Posted August 24, 2020 How hard is it to get the thermostat out? I had one stick shut once rolling down the road in Dad's C50 with the 350 truck motor. Gauge went up fast. Pulled off to the side, took out the t-stat, which was stuck shut, and drove on at normal temp (it was summer time). Point being it had been open but it closed when it failed. Quote Link to comment Share on other sites More sharing options...
Mudfly Posted August 24, 2020 Author Share Posted August 24, 2020 1 minute ago, Steve C. said: How hard is it to get the thermostat out? I had one stick shut once rolling down the road in Dad's C50 with the 350 truck motor. Gauge went up fast. Pulled off to the side, took out the t-stat, which was stuck shut, and drove on at normal temp (it was summer time). Point being it had been open but it closed when it failed. That I could probably get out myself. I would be a little worried about getting it resealed, but worth a try. Quote Link to comment Share on other sites More sharing options...
Dasnake Posted August 24, 2020 Share Posted August 24, 2020 Is the water pump weeping at all? Has any oil appeared in the rad water? is the rad plugged at all? is your rad reservoir full? stupid question but is your fan working? Clutch fan maybe seized. big thing like Steve said check the thermostat, easy peasy, take it out put in cold water check for closed then hot hot water check for open. good luck. Quote Link to comment Share on other sites More sharing options...
Mudfly Posted August 24, 2020 Author Share Posted August 24, 2020 6 minutes ago, Dasnake said: Is the water pump weeping at all? Has any oil appeared in the rad water? is the rad plugged at all? is your rad reservoir full? stupid question but is your fan working? Clutch fan maybe seized. big thing like Steve said check the thermostat, easy peasy, take it out put in cold water check for closed then hot hot water check for open. good luck. I don’t see it weeping but it was pretty hot And dark when I got it into town so it could be. I will check for fresh puddles and leaks in the morning. Quote Link to comment Share on other sites More sharing options...
Dasnake Posted August 24, 2020 Share Posted August 24, 2020 5 minutes ago, Mudfly said: I don’t see it weeping but it was pretty hot And dark when I got it into town so it could be. I will check for fresh puddles and leaks in the morning. You mentioned head gasket, do you smell any antifreeze out the exhaust pipe, also a quickie compression test could help, I’m sitting 2000 miles away thinking for tomorrow, there’s some really good guys here on mechanical knowledge but time difference is quite a bit. Again good luck. Quote Link to comment Share on other sites More sharing options...
New Englander Posted August 24, 2020 Share Posted August 24, 2020 Check the fan clutch. If it spins real freely it's no good. I pulled one out of an older Suburban that would get hot only on a grade. Clutch wasn't locking up. They're kind of hard to change without the holding tool as the water pump will just slip on the belt. I've changed a few pumps successfully by smacking the wrench with a hammer and it broke free. Good luck, I hope it's something simple and cheap! Quote Link to comment Share on other sites More sharing options...
yellowrosefarm Posted August 24, 2020 Share Posted August 24, 2020 Fan clutch. I just had to put one in my 02 Silverado 6.0. The fan shroud splits in half so it isn't that hard to do. I think a 1 3/8 wrench fits it well enough to smack with a hammer and loosen it. 1 Quote Link to comment Share on other sites More sharing options...
ZG6E Posted August 24, 2020 Share Posted August 24, 2020 I would think that unless you are loaded heavy just moving along at highway speeds should give plenty of airflow over the rad to keep it cool. Could you hear the fan whine when it was hot? I would be suspect of the thermostat. Quote Link to comment Share on other sites More sharing options...
kal Posted August 24, 2020 Share Posted August 24, 2020 On older fan clutches you could pry the spring off of the front of the clutch to lock it up. Quote Link to comment Share on other sites More sharing options...
jobee1066 Posted August 24, 2020 Share Posted August 24, 2020 8.1's have a rubber seal on the thermostat so no gaskets to worry about. I have switched several over to 180 degree stats which seems to help them. I agree with the others, start with the fan clutch. 1 Quote Link to comment Share on other sites More sharing options...
Mudfly Posted August 24, 2020 Author Share Posted August 24, 2020 28 minutes ago, jobee1066 said: 8.1's have a rubber seal on the thermostat so no gaskets to worry about. I have switched several over to 180 degree stats which seems to help them. I agree with the others, start with the fan clutch. 46 minutes ago, ZG6E said: I would think that unless you are loaded heavy just moving along at highway speeds should give plenty of airflow over the rad to keep it cool. Could you hear the fan whine when it was hot? I would be suspect of the thermostat. I could see it spinning with the hood open, but that doesn’t mean it was locked up. headed out to the truck now to take a look. Quote Link to comment Share on other sites More sharing options...
Mudfly Posted August 24, 2020 Author Share Posted August 24, 2020 46 minutes ago, ZG6E said: I would think that unless you are loaded heavy just moving along at highway speeds should give plenty of airflow over the rad to keep it cool. Could you hear the fan whine when it was hot? I would be suspect of the thermostat. With the engine off, the fan will spin but there is resistance. Feels like a couple of ft lbs of resistance, not a lot but it doesn’t spin freely either. no noticeable puddles this morning. No noticeable play in the water pump/fan shaft. thinking I’m going to pull the thermostat and take a look at it. Quote Link to comment Share on other sites More sharing options...
Mudfly Posted August 24, 2020 Author Share Posted August 24, 2020 Here is a quick vid of it running. A bit of a tick somewhere but I don’t think that’s related. Quote Link to comment Share on other sites More sharing options...
GT&T Posted August 24, 2020 Share Posted August 24, 2020 Mudfly Have you checked the radiator coolant level? You mentioned that the storage tank or reservoir was full. The radiator cap is under pressure and cannot be checked when the engine is hot as the coolant will blow out when the pressure is released. This will scald you and anyone near the vehicle. The reason I ask is, it is possible for the engine to be low on coolant, even though the storage tank or reservoir is full. I am on line and I will post this and wait while you check. I have more information, but will be writing it while you are answering. GT&T Quote Link to comment Share on other sites More sharing options...
Mudfly Posted August 24, 2020 Author Share Posted August 24, 2020 These don’t have a radiator cap. When I squeeze the top rad hose from the engine to the radiator the reservoir goes up. So I am pretty sure it’s full. Quote Link to comment Share on other sites More sharing options...
hardtail Posted August 24, 2020 Share Posted August 24, 2020 When I was hauling the trailer in the mountains it was easy to hear the fan lockup and then unlock from the cab in my 03? Quote Link to comment Share on other sites More sharing options...
jobee1066 Posted August 24, 2020 Share Posted August 24, 2020 It has a radiator cap, it's just on the overflow tank instead of the radiator. Quote Link to comment Share on other sites More sharing options...
Mudfly Posted August 24, 2020 Author Share Posted August 24, 2020 2 minutes ago, jobee1066 said: It has a radiator cap, it's just on the overflow tank instead of the radiator. Sorry, yes I misspoke. thermostat is pulled. We will see what happens now. Quote Link to comment Share on other sites More sharing options...
GT&T Posted August 24, 2020 Share Posted August 24, 2020 Mudfly If you suspicion a leaking head gasket, here is a quick check. With the engine off, fill the radiator full to the top, then start the engine and while running make sure the radiator is full. Then while the engine is running, with radiator cap off, look for bubbles or for the coolant level rising and over flowing. You will have some over flowing due to the coolant expanding from the engine warming up. GT&T Quote Link to comment Share on other sites More sharing options...
New Englander Posted August 24, 2020 Share Posted August 24, 2020 1 hour ago, Mudfly said: With the engine off, the fan will spin but there is resistance. Feels like a couple of ft lbs of resistance, not a lot but it doesn’t spin freely either. My experience with them is if bad you can spin them and they'll keep spinning. If you spin it and it only goes a few blades it may be ok. Quote Link to comment Share on other sites More sharing options...
Mudfly Posted August 24, 2020 Author Share Posted August 24, 2020 Update. 30 miles down the road. Cruising at 60. Temp running 180ish without the thermostat. 7 Quote Link to comment Share on other sites More sharing options...
Mudfly Posted August 24, 2020 Author Share Posted August 24, 2020 Thank you all. Quote Link to comment Share on other sites More sharing options...
mader656 Posted August 24, 2020 Share Posted August 24, 2020 Im guessing you started overheating in the marias river valley. That hill is killer. Glad your moving again. Quote Link to comment Share on other sites More sharing options...
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