Coolant on the Passenger Floorboard - '65 Chrysler 300 Factory AC

[rexus31]

While cleaning the car up this morning for a show tomorrow, I noticed the passenger floorboard was wet. Turned out to be coolant. The question is: heater core (god, I hope not) or temperature control valve? The drip tray below the temperature control valve was wet with coolant so I'm hoping that is a good sign. How can I tell if it is the heater core or control valve?

 

[Zymurgy]

Man that sucks Scott. Check the lines too going in and out at the firewall. I had an issue with a connection there and it flowed straight into the floor on the passenger side.

 

[rexus31]

Man that sucks Scott. Check the lines too going in and out at the firewall. I had an issue with a connection there and it flowed straight into the floor on the passenger side.

Thanks, Mike. I checked them but will check again. They all appeared dry upon first inspection.

Edit: Just checked. All dry in the engine bay at both connections.

 

[twostick]

I'm assuming the water valve isn't inside the heater box.

Warm it up to operating temp and turn on the defroster. If it fogs the windshield and blows the fragrance of hot Prestone through the car, you're looking at a heater core, again assuming the valve and hoses are external to or not in the hot side air circulation path of the blower.

Kevin

 

[polara66hardtop]

if it is a 65-66 C body the control valve is directly above your picture in front of glovebox. It usually leaks only when you activate the valve, or if the engine warms up. so then the core is a possibility. Unfortunately to work on it, the console has to move. my 66 Polara had the same Issue.

 

[JC68vert300]

You can just bypass it so you can go to your show tomorrow.

 

[rexus31]

You can just bypass it so you can go to your show tomorrow.

I'm still not sure if it is the heater core or the heater valve. Unfortunately, I do not have much time today to diagnose. I was able to remove the part of the heater valve that connects to the bottom of the plenum. I stuck my finger up there and everything felt dry. I would imagine the foam insulation inside would be damp if it had gotten wet.

 

[rexus31]

I'm assuming the water valve isn't inside the heater box.

Warm it up to operating temp and turn on the defroster. If it fogs the windshield and blows the fragrance of hot Prestone through the car, you're looking at a heater core, again assuming the valve and hoses are external to or not in the hot side air circulation path of the blower.

Kevin

Thanks. The heater control valve is external and mounted high up on the passenger footwell.

 

[rexus31]

if it is a 65-66 C body the control valve is directly above your picture in front of glovebox. It usually leaks only when you activate the valve, or if the engine warms up. so then the core is a possibility. Unfortunately to work on it, the console has to move. my 66 Polara had the same Issue.

To remove the heater core, did you have to remove the entire evaporator unit or can it be done with it in the car?

 

[saforwardlook]

I seem to recall from the past their are two heater valves in that model, but since I haven't actually worked on one, I could be wrong. Did Original Auto Air replace the heater core when they refurbished your entire cooling box?

 

[rexus31]

I seem to recall from the past their are two heater valves in that model, but since I haven't actually worked on one, I could be wrong. Did Original Auto Air replace the heater core when they refurbished your entire cooling box?

Hey, Steve. In reading my invoice, they installed a new Heater Core for $239.00 and rebuilt the Heater Water Valve for $125.00.

 

[saforwardlook]

Since they did replace the heater core, I would suspect the heater valve as most likely since you keep your coolant nice and clean. It is also more likely to go bad in short order compared to the heater core. Unfortunately on those models, they put the valve inside the car rather than out in the engine copartment, but if it is like my 1962 Chrysler in terms of where they mount the valve (upper right side of the firewall above the right kick panel, it might well be accessible but on my cars I almost need to be a contorsionist to get it out. But it is doable. One nice thing about the 60 - 64 models is that the heater core is in the engine compartment (piece of cake!) and changing the heater core in those is preferable to changing the heater valve. But on your car, everything is in the passenger compartment.

 

[rexus31]

Since they did replace the heater core, I would suspect the heater valve as most likely since you keep your coolant nice and clean. It is also more likely to go bad in short order compared to the heater core. Unfortunately on those models, they put the valve inside the car rather than out in the engine copartment, but if it is like my 1962 Chrysler in terms of where they mount the valve (upper right side of the firewall above the right kick panel, it might well be accessible but on my cars I almost need to be a contorsionist to get it out. But it is doable. One nice thing about the 60 - 64 models is that the heater core is in the engine compartment (piece of cake!) and changing the heater core in those is preferable to changing the heater valve. But on your car, everything is in the passenger compartment.

The Heater Control Valve is mounted at the top of the passenger footwell and is easily accessible. Looks like I'll have to top off the radiator, put some plastic and old towels on the floor and test it. Maybe I'll have some time tomorrow.

 

[rexus31]

It's the Heater Control Valve! Thank you Baby Jesus! I was dreading the Heater Core job.

 

[Zymurgy]

That is great news.

 

[rexus31]

That is great news.

Mike, you have no idea. The curse words would have been heard for miles had I needed to remove the Heater Core.

 

[Zymurgy]

Mike, you have no idea. The curse words would have been heard for miles had I needed to remove the Heater Core.

You should have rebuilt that before you put it in the first time.

It's like a guy who had his engine out of the car and didn't rebuilt it at that time, even though guys advice him to.

 

[rexus31]

You should have rebuilt that before you put it in the first time.

It's like a guy who had his engine out of the car and didn't rebuilt it at that time, even though guys advice him to.

Sadly, it was rebuilt by Classic Auto Air along with the entire AC system.

 

[Zymurgy]

Sadly, it was rebuilt by Classic Auto Air along with the entire AC system.

Really, but it doesn't surprise me that you had it done right.

 

[rexus31]

Really, but it doesn't surprise me that you had it done right.

Parts fail. It is what it is. I'm just glad it wasn't the Heater Core.