| Overheating problem in 1992 Dodge B250 van
I have a van that still has an overheating problem though it has been to the shop. The places that did the repairs replaced one of the heater hoses and the bypass hose which fixed the initial problem of overheating and leaking coolant. The leaking has not occurred since then. However, the temperature guage started to rise rapidly when going 55 mph on the highway. This was about 20 miles into the trip. Before that point, the temperature guage was indicating that the engine was at the normal operating temperature. So, I pulled over to check out what was going on. I checked underneath for leaks and found none. When I checked the coolant overflow reservoir, the tube going to it from the neck of the radiator was too hot to touch and the water was bubbling (possibly boiling). Also, I could hear boiling from inside the radiator when I put my ear close to the radiator cap without burning myself. I let it cool for a while and started it back up again, when I put the engine to about 1500 RPM, the temperature reported on the guage would decrease back to operating temperature. I'm thinking that the radiator could be clogged as some radiator stop leak has been placed in it before.
The ambient temperature at which this occured was about 85 degrees Fahrenheit to 90 degrees Fahrenheit. Turning the heat on to maximum heat decreased the temperature, but it rose back up about 2-3 miles later.
The engine in this van is a fuel injected 318 cu. inch (5.2 L) V8.
Once the engine cooled enough to open the radiator cap, the coolant level was the same as that with which I started. So, I lost no coolant.
The water pump was replaced back in April of 2006.
Does anyone have any ideas as to the cause?
Would a blown head gakest be another possible culprit causing these symptoms? (I think it is unlikely since I'm not losing coolant)
Thanks in advance for any ideas that can be offered.
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