1G Coolant leak after replacing heater core

[Zero_Jay]

So I have a coolant leak leaking into the driver side of the talon, I spent all day replacing this heater core with a new one. It was all fine for a few days till I was using the heater and started to smell coolant. Then I looked under my foot and it was all over, I’m kinda at a lost and back on the drawing board and would like some ideas to troubleshoot this. Thanks!

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[pauleyman]

sadly looks like you're doing the job again. You might check the hose connections although I wouldn't think those wouldn't get any coolant into the car.

 

[Zero_Jay]

sadly looks like you're doing the job again. You might check the hose connections although I wouldn't think those wouldn't get any coolant into the car.

That’s what I’m thinking. I might have a defective heater core because the air coming from the heater has a sweet smell. Or the heater core was never the problem in the first place

 

[Tavarez]

It could be due to a faulty thermostat or radiator cap.. you might as well check them

 

[CKOPOCT]

Unfortunately no reason for coolant puddling inside aside from the heater core. If the hose clamps were leaking you'd see it outside more than in. Only possible exception might be if the clamp was seriously over tightened causing the heater core pipe to buckle - creating a crease or gap that didn't seal under pressure. Then you (might) get a spray of coolant directed into the cab, but it'd have to get past the rubber dam as well and you'd probably see it outside too. If you're smelling coolant with the blower fan on, order a new heater core.

FWIW - I ordered a core from wherever and saw that it was poorly made and didn't fit properly - the pipes weren't bent at the correct angle and the only way to get it to fit would have been to force the issue when bolting the case back together. This would likely have caused the pipe joint to crack where it was braised. I only mention this so you don't make the same mistake I almost did (assuming the replacement part was actually made to spec by the Chinese).

 

[BLACK'98DSM]

I don't see how a faulty radiator cap would cause coolant to come inside the car...

 

[waltah]

In most of these systems -- I don't know the Eclipse * -- the heater core always has pressurized coolant flowing through it; control of heat is by controlling what fraction of the air goes through there. A core leak will be constant (even with heat off) though if there's a place that can trap a puddle it might not get to your feet until you turn on the heat (= air flowing through core).

I assume you replaced the heater core because of a leak. Is there a chance it left fluid puddled in a place you didn't see and you just blew it on through the ducts when you turned on the heat diverting the blower air through the heater core? I'd start by doing nothing until you're sure the leak really is ongoing.

Before pulling the core you should inspect the hose connections in the engine compartment carefully: In other Mitsubishi's of that vintage I've seen the seals that should prevent a leak from squirting into the passenger compartment torn so a bad hose connection could cause fluid to run along the pipe to the inside.

* I don't know the Eclipse system yet. Since my A/C is dead that won't last past the spring.

 

[CKOPOCT]

to

Agree. Only way a bad rad cap would cause it is if the cap didn't relieve pressure so the system continued to build pressure and eventually blew through a weak point in the heater core. 'Course, I'd think one of the hoses would blow first, or at least balloon and break the fibers inside...

Not saying a stuck shut cap couldn't cause an issue, but the core would have to be severely weak, pointing to a core replacement anyway...

 

[Purevil]

The 2 hoses connect on the engine side of the firewall. A bad connection will not leak inside the car. You have a bad heater core. Maybe it got a puncture before being installed.

 

[Zero_Jay]

So I have a coolant leak leaking into the driver side of the talon, I spent all day replacing this heater core with a new one. It was all fine for a few days till I was using the heater and started to smell coolant. Then I looked under my foot and it was all over, I’m kinda at a lost and back on the drawing board and would like some ideas to troubleshoot this. Thanks!

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So reading everything I’m going to just take it apart and check the core. I’m also going to also remove the carpet and follow where it’s coming from because it’s not dripping more puddling up from a run somewhere. And it couldn’t have been left over coolant from the previous core mainly because I cleaned up and dried up everything.

 

[BLACK'98DSM]

Add some dye to the coolant and use a blacklight in the dark to find where it's running down from

 

[TerminalTalon]

Before you pull anything pressurize the system with a pressure tester. Have soapy water available to spray and actually see where it is coming from. I continually see people complain about heating/cooling but not much explanation of why except replacing parts.