Leaky heater core?

[davess]

Hey brains trust, I've got an 89 D21 Z24 and I think it has a leak or more correctly a weep in the heater core. I'm not 100% the only reason I suspect it's gone is that the last few times I have put the heat on with the fan set to de-mist the windscreen has fogged up fairly fast and only adding a/c to the fan has cleared it. Is there an easy to access inspection panel I can open up to have a look or is it a case of having to remove the whole core to inspect it?
cheers, dave

 

[Krankin]

well if it is leaking as you suspect, it will have to come out anyway

 

[Old.Tony]

When the engine is cool, open the radiator and smell the water. Does it smell a bit like that inside?

What you could be seeing is condensation that is caught in the water trap under your air conditioner's cold side. This might just be a blockage of the tube that runs down and outside the cabin.

 

[Dave]

What the guy below said.

No sleep will do that.

 

[Scottar]

Every car I have ever owned does that. I always run with the AC on to demist the windows because it dehumidifies the air. Its either that or there's too much heavy breathing going on. lol.

 

[Scubamurph]

What Old Tony said. If your core is leaking the inside will smell of coolant.
Is the floor wet under the vents for the foot wells?

Normally replacing the heater core involves a complete dash removal as manufacturers
for some reason don't like making them easy to access. Replacement parts are usually
pretty cheap compared to labour costs to remove dash, replace core and refit dash.

If doing your own work allow around a day to strip everything out and refit (help usually
required to manhandle dash out and in). Maybe a little longer if you have not done it before.

Hope it is the aircon drain mate. Much easier fix.

Regards Murph

 

[Krankin]

where do you live and whats the weather been like?

 

[davess]

I'm in Melb and the weather has been all over the shop lately. There's no pooled coolant or apparent leakage which is why I was thinking it might be only weeping and not actually leaking just yet.

Dash out is going to be a royal pain, I'm a licensed a/c fitter so i guess the core is not too unlike an evaporator. I might get the cooling system pressure tested before I go pulling anything apart it could save doing a heap or work unnecessarily.

cheers all

 

[Scottar]

Davess,

I'm in Brissie and with the humidity up here you have to run the AC with the heater or the windows do fog. If you have a fairly high humidity level could just be that. Has the coolant level in the radiator been dropping at all? If not probably nothing to worry about.

 

[Krankin]

Davess,

I'm in Brissie and with the humidity up here you have to run the AC with the heater or the windows do fog. If you have a fairly high humidity level could just be that. Has the coolant level in the radiator been dropping at all? If not probably nothing to worry about.

precisely what i was getting at.....

but a cooling system pressure test is the way to go....normally a big coolant leak in the cabin would be needed to fog up the window and you would notice the coolant and smell in the cab,
alternativly high humidity will do it also.