99 Ford Ranger 3.0L

When you say it reads hot, do you mean overheat hot? Also, is the hissing coming from the radiator? Is the coolant full and not overflowing?

One last question. With the engine at operating temp, running, and the heater on high, do both heater core hoses get hot?

Let me know.

Joe

You are correct. The heater core hoses run to the firewall (rear of dashboard engine side). If neither is hot, there is no coolant flowing. Either you have a plugged heater core, air pocket, low on coolant, or you could have bad head gasket allowing compressed air to get into the system and blocking it.

I would start simple. First, with the engine cold, remove the radiator cap and make sure coolant is full. If it is, replace the cap and loosten the heater core return hose and start the vehicle. See if air comes out. If it does, make sure the coolant overflow stays full. If that still doesn't help, replace the thermostat and flush the radiator and heater core. It that still doesn't help, you need to check engine compression to make sure there isn't a bad head gasket.

This sounds like a lot of work, but really it isn't. If you want to do it, let me know and I will walk you through it. It isn't as bad as it sounds.

Let me know. I have to admit, the hissing sound you are hearing has me a bit concerned. Are you sure none of the hoses are collapsing causing a restriction and a hissing sound?

That is the temp sending unit. Is the crack in the electrical component or the steel item the sensor screws into? As far as the part, you can get them all. However, the if it is the steel component that the sensor screws into, it will be a dealer part or junk yard part. The sensor, which can go bad a leak, can be purchased at any parts store.

Based on the rust color on the hoses, it has been leaking for some time. Also, I would recommend flushing the entire cooling system. It appears as though there is a lot of rust and dirt in the system.

Let me know if you have other questions. As far as the epoxy, IF it works, it will only be a temporary fix.

Joe

Glad to help. Let me know how things work out for you, and if I don't hear from you, have a great New Year!

Joe

I'm glad you got it going. The epoxy should hold for some time, but I would be concerned if I took a longer trip. Who knows, it may last longer than the original one did. As far as the flush, it wouldn't be a bad idea. Make sure when they do it, they flush the engine block and heater core too. They will need to remove the thermostat to do it, so keep an eye on them so they do it.

Let me know how things work out for you, and I wish you and your family a Happy New Year!

Thanks for using 2carpros. Com, and let us know if you have questions in the future.

Joe