FORD 460 Overheating Mystery
1997 Fleetwood Southwind 35P ~Ford 460 engine.
I noticed the rig running a bit warm when we first got it 5 years ago. It had 23K miles on it then. It seemed each trip it would run a little more on the hot side of the dash gauge during long interstate trips. During stop and go around town, everything seems just fine, even when it's 110 outside.
Then we started flat-towing a Jeep Wrangler TJ. I expected the temps to increase but I noticed that on inclines, the dash gauge would nearly peg on hot. I could tell the rig was hot.. This would only happen on highway trips...worse on inclines.
One time after traveling for 2.5 hours at 60-65mph, we got off the highway and when we pulled into the gas station, the engine seemed to be vapor-locking..like it was starving for fuel. After 2 hours of letting it cool off, I was able to feather the throttle enough to keep it running to get it home. It doesn't do this vapor-locking thing unless we run long distances at a time, and not every time. It has only done it once before after a 40 minute incline. I actually unscrewed the gas cap thinking that maybe rapid fuel consumption from the tank cause some vacuum or fuel flow resistance..or ?
I then had the radiator, water pump, and thermostat replaced. No difference. I replace the fuel pump, changed the fuel filter, had the carburetor adjusted..no difference.
Thinking that the dash gauge could be off, I replaced the temperature sending unit and gauge with a number dial. The rig runs down the highway at 245 degrees if I'm not towing. If I'm towing, 245 to 258 degrees uphill.
I can hear the clutch fan kick in at 230 to 240 degrees or so...maybe sooner ..and it does cool it down a few degrees so I know it's working.
Are these temps bad? It seems high to me but maybe this is perfectly normal? I don't think it is. The rig runs perfectly..smooth as can be.
The problem seems like it has gotten progressively worse. Our last trip up to the mountains towing, it got to 258 degrees ...the highest I've seen it yet.
There are only 2 things that I can think of that could cause this.
1. Blown head gasket. This makes sense because the problem seems to happen under load. Perhaps there is a leak that's pushing hot exhaust gasses into the coolant? When things are under load, they heat up, causing expansion, and making the leak worse?
If this were true, I would expect to see some foam in the engine oil...but I don't.
2. Transmission issue. I believe the tranny is cooled by the same engine coolant. It shifts perfect, does not slip at all. I have no idea how to test to see if this is the cause of the overheating issue...any suggestions here would be appreciated.
Solutions.
1. Sell it.
2. Take it to a head shop and have the head gaskets replaced.
3. Put STEEL SEAL Head Gasket Sealer in it and cross my fingers. (Has anyone tried this?)
4. Pretend that these temperatures aren't anything to worry about until my rig blows up.
5. ??? Thoughts?
Thanks in advance for any insights.
I noticed the rig running a bit warm when we first got it 5 years ago. It had 23K miles on it then. It seemed each trip it would run a little more on the hot side of the dash gauge during long interstate trips. During stop and go around town, everything seems just fine, even when it's 110 outside.
Then we started flat-towing a Jeep Wrangler TJ. I expected the temps to increase but I noticed that on inclines, the dash gauge would nearly peg on hot. I could tell the rig was hot.. This would only happen on highway trips...worse on inclines.
One time after traveling for 2.5 hours at 60-65mph, we got off the highway and when we pulled into the gas station, the engine seemed to be vapor-locking..like it was starving for fuel. After 2 hours of letting it cool off, I was able to feather the throttle enough to keep it running to get it home. It doesn't do this vapor-locking thing unless we run long distances at a time, and not every time. It has only done it once before after a 40 minute incline. I actually unscrewed the gas cap thinking that maybe rapid fuel consumption from the tank cause some vacuum or fuel flow resistance..or ?
I then had the radiator, water pump, and thermostat replaced. No difference. I replace the fuel pump, changed the fuel filter, had the carburetor adjusted..no difference.
Thinking that the dash gauge could be off, I replaced the temperature sending unit and gauge with a number dial. The rig runs down the highway at 245 degrees if I'm not towing. If I'm towing, 245 to 258 degrees uphill.
I can hear the clutch fan kick in at 230 to 240 degrees or so...maybe sooner ..and it does cool it down a few degrees so I know it's working.
Are these temps bad? It seems high to me but maybe this is perfectly normal? I don't think it is. The rig runs perfectly..smooth as can be.
The problem seems like it has gotten progressively worse. Our last trip up to the mountains towing, it got to 258 degrees ...the highest I've seen it yet.
There are only 2 things that I can think of that could cause this.
1. Blown head gasket. This makes sense because the problem seems to happen under load. Perhaps there is a leak that's pushing hot exhaust gasses into the coolant? When things are under load, they heat up, causing expansion, and making the leak worse?
If this were true, I would expect to see some foam in the engine oil...but I don't.
2. Transmission issue. I believe the tranny is cooled by the same engine coolant. It shifts perfect, does not slip at all. I have no idea how to test to see if this is the cause of the overheating issue...any suggestions here would be appreciated.
Solutions.
1. Sell it.
2. Take it to a head shop and have the head gaskets replaced.
3. Put STEEL SEAL Head Gasket Sealer in it and cross my fingers. (Has anyone tried this?)
4. Pretend that these temperatures aren't anything to worry about until my rig blows up.
5. ??? Thoughts?
Thanks in advance for any insights.
