2002 Leaking Coolant & Overheating

[Blackbird]

Thunderbird is leaking coolant and overheating. I replaced the filler reservoir several months ago because it was abraided from rubbing the firewall and leaking under pressure. Now, I seem to have a leak from the same place. When it gets good and hot there is coolant dripping from under the car about even with the firewall, about two feet inboard. I can see the hose from the coolant tank is not leaking. This hose is hard to attach when you replace the coolant tank. It seems OK. Any ideas?

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[biddle]

Use the seach page for the 2002-2005 forums only for coolant leak & overheating and you will find many past discussions that may help.

Check your thermostat housing for cracks.

Current overheating may be from not bleeding the system which is more complex than many engine.

This shows the air bleeding process.

 

[Chopt34]

As the moderator suggested, search the topic. I recently went through this. Coolant is leaking in the upper coolant lines and flows back through the valley under the intake and flows down the back of the engine. There is a rubber hose under the intake manifold that leads to the throttle body that cracks and leaks under the manifold. I suggest changing all of the rubber and plastic components at the same time since the rubber and plastic components will all eventually fail. I serviced the serpentine belt while I has it out, I found it is easier to get to the components without the belt in place. Don't hesitate to reach out, there are a lot of experienced resources that can help you through the process. A couple of special tools purchased in advance will save you a lot of time.

 

[Blackbird]

I am suspecting that rubber hose underneath the intake manifold. However, and this is maddening, I TRIED to overheat the car yesterday by running and idling it. It didn't overheat and it didn't leak. How can that be possible?? I would think it is going to overheat and leak in the future.

 

[centexrider]

This is all sounding very familiar to me, and I hope I can help. My 04 overheated at a stop light a couple of months ago. I pulled to the shoulder asap when the signal turned green and shut it down immediately (car was in limp mode by now) and got it towed home. I got a coolant system pressure checking kit, but only saw where I could pressurize the system at the Degas bottle near the firewall. When I pressurized the system at the bottle with the motor cold, there was a slight leak behind the bottle, so I changed it (battling that hose at the firewall is another story). Anyway, when I refilled the system and ran the engine, I eventually saw coolant leaking from somewhere to the rear of the engine in front of the transmission. (Like it has already been pointed out, coolant can and will run from the front of the engine underneath to the rear, having you look extensively there and scratching your head.) Anyway, what I did NOT know is that there is another coolant cap underneath a plastic cover at the thermostat at the front of the engine. If you remove that cover you can pressurize your system there. Do that and I'll bet you will find your leak (coolant dye and black light can help). In my case (see attached pic) it was a plastic tube between thermostat housing and the engine that was cracked. I finally had it towed to a mechanic and he had to remove the intake to replace the piece (though I daresay with patience and "holding your mouth just right" it could be done without removing the intake). Anyway, the car's been running nice and cool ever since even in this hot Texas weather. Hope this helps. BTW, if you find the leak at the thermostat housing (a new one usually comes with a new thermostat), I strongly suggest you replace this short connecting piece as well. Oh, and carefully watch where all the gaskets and rubber fittings are. You may have to purchase those separately. Good luck!