RustyOlds

Heater doesn't work when I turn it on the vents spew exhaust smelling fumes, defroster doesn't work either. I assume this just means the core is gunked up but what do you guys think?

oldcutlass

Is there a heater core in there? Is there an opening from the firewall where fumes are entering?

MDchanic

There is no connection between the heater and the exhaust system (unlike in a Volkswagen), so, as Eric said, you need to find out where the exhaust fumes are getting in.

When you say the heater "doesn't work," do you mean that the fan doesn't turn on, or that the fan turns on, but no air comes out, or something different?

- Eric

BangScreech4-4-2

Do you have a Corvair?

Octania

You can't have exhaust fumes in the passenger compartment. Well, you -can- but mustn't.

Does it fog the inside of the windshield? I wonder if what you are calling an exhaust smell is antifreeze smell from a leaky heater core.

More info is needed.

RustyOlds

Well the fan turns on because there is airflow from the vents. Also from what I've seen nothing fogs up.

Octania

Descibe what exactly you think is a problem.

WHat is it doing wrong?

For what it's doing right, I am hearing the blower works, and air comes out the vents.

I presume it is the '69 Cutlass shown.


"when I turn it on the vents spew exhaust smelling fumes"
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There should not be any way for exhaust smelling fumes to get into the HVAC system.


defroster doesn't work either.
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Control cables feel right? No defrost could just be low coolant level - ck the basics. When it warms up, does the engine get hot like it should? Do the hoses to/from the heater core get hot? Basic hands-on inspection will reveal much.


"I assume this just means the core is gunked up"
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You didn't mix green and orange coolant did you?
Drain some coolant.
Remove heater core hoses from whichever end is handiest, probably fwd ends.
Flush with water both ways, see what comes out. See if the flow is a reasonable amount.

RustyOlds

For the coolant, I didn't mix the coolants but I figured it's full of gunk because I know that's a common problem for the cores. Engine heat is ok but air from the vents never gets hot. On note of cables & hoses, I have yet to run a proper inspection. However all of this aside it is possible the previous owner may have done something to mess up the core. Flushing sounds like a good idea, I've heard that helps a lot

Fun71

Actually, if the cowl seal doesn't seal properly, then anything under the hood can be sucked into the HVAC air inlet. This would suggest there is an exhaust leak (maybe VC breathers and no PCV valve?) as well as a cowl seal leak.

MDchanic

What, exactly, do you mean?

You say "Heater doesn't work" and then you say "Engine heat is okay."

- Eric

Inline

Engine warms to normal operating temperature, but heater isnt blowing "corresponding" heat out of the vents? In this case, id advise your heater core is gone.
OR it MIGHT been changed.
Dont know about spare parts from these cars, but in Volvo's there are certain bad spare heater cores, which dont heat the air too much even when their brand new. Bad design on those.

Octania

Sometimes there is a vacuum operated valve at the right rear corner of the engine which dis/allows flow of heated water to the heater core.

Got one of those?
Been replaced? With wrong type?

RustyOlds

Yes this is what I mean