My f350 is overheating regularly and I need some advice. It blows a little white smoke for a minute or so upon cold start. When running at highway speeds the temperature gauge starts to climb. Normally it will run just outside the normal range on the cold side, then it will climb to about the middle of the gauge. The radiator boils over into the reservoir and boils out the top. Resulting in about 1 gallon of coolant loss per day. This is when the truck has no load. I live in the mountains with high altitude, steep grades and fast speed limits. I bought the truck to haul horses with but dont dare hook up to it right now. I flushed the radiator and next on my list is a thermostat. What do you guys think. Can't hear the fan clutch engaging because of the stack right next to my head.

 

Sounds like a blown head gasket, or cracked head. What engine? The white smoke is where I get my opinion from.

Craig

 

7.3 international idi. Seems to run just fine aside from the overheating.

 

Take the radiator cap off when the engine is cold. Start it up, or better yet have someone start it for you while you listen for the fan clutch. It should engage for a while even when cold, until the silicone fluid inside gets distributed evenly. Let it warm up (feel the upper radiator hose, when it gets warm then you know the thermostat is open) and then look inside the radiator. Should be able to see coolant flow, especially if the level is down a bit. Then, if your a/c works, put the cap on and engage the a/c, let the truck idle a bit. The hot air coming off the condenser and radiator should warm up the fan clutch and cause it to engage, so after a few minutes you should hear the fan when you increase engine RPM's.

If you're upper radiator hose never gets hot, your t-stat is probably stuck. If you don't see flow, your water pump took a dump. If the fan clutch never engages, well then it's junk.

I don't own a diesel, but as far as I know a little white smoke on startup is caused by unburnt fuel on a cold engine... do your glow plugs work alright?

Does your engine oil look good, or is it a milky tan color?

There are kits available that test for combustion gas in your coolant (which indicates one of the above problems) but I've never used one so I can't say if they're reliable or not.

 

When the engine is off, just grab the fan and spin it. Fan clutches when in good condition have resistance to them. Not a whole lot, but enough to know that it's there. If it's super easy, as if there were little to no resistance at all, I replace them. This method has always done me good

 

Are you loosing or using antifreeze? If you are then I;d think maybe a bad head gasket or overheating . If your fan clutch is not working it could be the culprit .to check fan clutch put a light blanket in front of radiator .when engine warms up and fan clutch engadges the fan should suck the blanket in if not then you need a new visious fan clutch

 

Hey all,
Just an update....... was leaking coolant bad one day and had it towed to the stealership since I needed to pick up a new thermostat from them anyways. After 4 business days it hadnt moved. So I towed it to a local family owned shop. The dealership said it was the water pump so I had that replaced and had them do the thermostat while they were into it.Picked it up and it overheated again after 6 hours of having it back. While I was trying to look at it on the side of a mountain road in the pitch black......I slipped and cracked a fuel return line to an injector. Took it back to our local family shop and told them to check the entire cooling system and do whatever they thought. They ordered the return line kit, and in less than 20 hours had it delivered and installed, tested the cooling system and fixed the problem. Turns out it was a worn out radiator cap ......a 10 dollar fix. Well with 650 bucks down the drain I have a new water pump, fuel return lines, thermostat and radiator cap. No more overheating issues