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Q: My truck overheats, blown head gasket.

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I have a 1993 Ford F150 with a 302 Windsor. 206K on it.

My mechanic did a pressure test on it because it was overheating, and we found out the head gasket is blown, gas fumes getting in the cooling system, etc.

He suggested using a one-time gasket sealer, rather than spend $1500 to $2000 to strip the engine down and re-do the head gaskets. The truck is barely worth $800, but it gets me to work and back.

However, it is still overheating and I noticed there was a pretty good hole in one of the heater tubes. I replaced both of the tubes tonight, hoping that was PART of the problem contributing to the over heating. But now, I have radiator fluid leaking INSIDE the cab on the passenger side, where the heater tubes connect to the cab!! ARGH!

What could possibly be going on now, because, there is still adequate radiator fluid in the overflow tank, and it does NOT appear to be leaking elsewhere from the engine.

Thanks!!

Randy Rankin Muncie, IN

My car has 206000 miles.
My car has an automatic transmission.

A: Sorry, but there is simply no reliable quic...

Sorry, but there is simply no reliable quick fix for a blown head gasket. I am not a fan of "mechanic in a can". They rarely work, and when the do, it doesn't usually last very long. Many sealants work or cure when they reach air at the source of the leak. The additive can't tell the difference between air outside of the system and air inside of the system. This can cause the sealant to essentially plug portions of your heater core and radiator when there is air in the system.

With a blown head gasket, combustion gasses are forced into the cooling system and the air pockets it creates are where the plugging can occur. Overheating can occur when coolant does not flow as the designed pace through the system. When there is air in the coolant system, cavitation occurs causing the water pump to have nothing to push against and coolant flow momentarily stops or slows down to the point that the cooling system can't properly remove the heat. This happens more often at higher speeds.

Your first step is to repair ALL the leaks your vehicle has. Do not rely on the overflow tank to show the correct level with a leaking heater hose. As your engine cools, it is designed to create a slight vacuum to pull coolant from the overflow bottle into the radiator. With a leaking system, the vacuum simply takes the path of least resistance and pulls air into the system through the leaking area. After all leaks are repaired, the rest of the system should be inspected and tested to ensure the thermostat, water pump, and other components are in good working order. A certified technician, like one from YourMechanic, will have the tools and knowledge to properly test and diagnose your cooling system.

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