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> Can't Turn the Heater Off, And smells like exhaust...
Jackba
post Jul 16 2018, 08:57 AM
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I hadn't driven my 74 2.0 for several months due to work on another project. Took it out yesterday and it felt like the heater was on full blast, plus it smelled like exhaust in the cabin. Top was on ant it was a hot day but I've never experienced that sensation before. The heater controls were in the off position.
When I restored my car a few years ago I pressure checked the heater boxes an they were good.
Any ideas?
Thanks,
Jack
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IronHillRestorations
post Jul 16 2018, 09:07 AM
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Could be a stuck heater flapper box, or heater cable. I've seen the flapper box stuck open due to a broken impeller blade that worked it's way into the flapper.
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Jackba
post Jul 16 2018, 09:29 AM
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QUOTE(Perry Kiehl @ Jul 16 2018, 10:07 AM) *

Could be a stuck heater flapper box, or heater cable. I've seen the flapper box stuck open due to a broken impeller blade that worked it's way into the flapper.

Thanks Perry. I'll check them out.
Jack
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troth
post Jul 16 2018, 09:48 AM
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QUOTE(Perry Kiehl @ Jul 16 2018, 11:07 AM) *

Could be a stuck heater flapper box, or heater cable. I've seen the flapper box stuck open due to a broken impeller blade that worked it's way into the flapper.


An issue I had was a little less unlikely. I pushed the stainless steel connector tube that attaches to the flapper box too far into the flapper box. This wedged the flapper open just enough so my passengers would have heat on their feet in the middle of August in Florida (IMG:style_emoticons/default/blink.gif)
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Jackba
post Jul 16 2018, 10:00 AM
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QUOTE(troth @ Jul 16 2018, 10:48 AM) *

QUOTE(Perry Kiehl @ Jul 16 2018, 11:07 AM) *

Could be a stuck heater flapper box, or heater cable. I've seen the flapper box stuck open due to a broken impeller blade that worked it's way into the flapper.


An issue I had was a little less unlikely. I pushed the stainless steel connector tube that attaches to the flapper box too far into the flapper box. This wedged the flapper open just enough so my passengers would have heat on their feet in the middle of August in Florida (IMG:style_emoticons/default/blink.gif)

I have mine connected with 914 Rubber's silicone hoses.
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troth
post Jul 16 2018, 11:13 AM
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QUOTE(Jackba @ Jul 16 2018, 12:00 PM) *

I have mine connected with 914 Rubber's silicone hoses.


I am talking about the metal "warm air elbow" that attaches the aft end of the heater box to the heat exchanger. Not the paper hose that goes forward from the heater box to the body.
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Jackba
post Jul 16 2018, 11:15 AM
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QUOTE(troth @ Jul 16 2018, 12:13 PM) *

QUOTE(Jackba @ Jul 16 2018, 12:00 PM) *

I have mine connected with 914 Rubber's silicone hoses.


I am talking about the metal "warm air elbow" that attaches the aft end of the heater box to the heat exchanger. Not the paper hose that goes forward from the heater box to the body.

AH, ok, I'll look at it.
Thanks!
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Dave_Darling
post Jul 16 2018, 11:42 AM
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The flap inside the flapper valve is two pieces held together with a rivet. When the rivet fails, I think the heat is always diverted into the cabin. So even if the arm on the outside of the valve is in the correct position and moves freely, you should pull the hose off and inspect.

--DD
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Bartlett 914
post Jul 16 2018, 11:48 AM
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QUOTE(Jackba @ Jul 16 2018, 09:57 AM) *

I hadn't driven my 74 2.0 for several months due to work on another project. Took it out yesterday and it felt like the heater was on full blast, plus it smelled like exhaust in the cabin. Top was on ant it was a hot day but I've never experienced that sensation before. The heater controls were in the off position.
When I restored my car a few years ago I pressure checked the heater boxes an they were good.
Any ideas?
Thanks,
Jack

Smelling like exhaust in the cabin is a red flag. Just because you tested them a few years ago and they were good does not mean they are still good.
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rjames
post Jul 16 2018, 01:24 PM
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QUOTE(Bartlett 914 @ Jul 16 2018, 10:48 AM) *

QUOTE(Jackba @ Jul 16 2018, 09:57 AM) *

I hadn't driven my 74 2.0 for several months due to work on another project. Took it out yesterday and it felt like the heater was on full blast, plus it smelled like exhaust in the cabin. Top was on ant it was a hot day but I've never experienced that sensation before. The heater controls were in the off position.
When I restored my car a few years ago I pressure checked the heater boxes an they were good.
Any ideas?
Thanks,
Jack

Smelling like exhaust in the cabin is a red flag. Just because you tested them a few years ago and they were good does not mean they are still good.



(IMG:style_emoticons/default/agree.gif)

And exhaust fumes in the cabin is nothing to fool around with.
Take for example this couple that literally fooled around with carbon monoxide in the cabin:
Lovers die from carbon monoxide poisoning
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Jackba
post Jul 17 2018, 09:13 AM
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I'll have time today use these suggestions to hopefully diagnose the problem. My initial concern was the smell of exhaust for obvious reasons. If I'm thinking about this correctly, would there be any other reason for the exhaust smell than a failure of the exhaust pipe in the heater box?
Thanks to everyone who responded. Much appreciated!
Jack
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Dave_Darling
post Jul 17 2018, 12:31 PM
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One possibility is your mistaking burning oil for exhaust.... But CO is nothing to mess around with; at least get a detector and check what's coming into the car.

--DD
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GeorgeRud
post Jul 17 2018, 09:26 PM
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I keep a basic CO monitor from Home Depot in the c3nter deposit as even SSI heat exchangers can crack and allow exhaust into the cabin. Best to be safe and these cars are getting old.
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r_towle
post Jul 18 2018, 06:27 AM
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Until you really want to fix it, which may take a while...
Remove the two rubber hoses that connect the flappers to the chassis tubes.
Grab two standard spray paint (rattle can) covers and put them over the tubes that lead into the chassis. The right ones fit like a glove.
Use a couple of large screw clamps that held the rubber tubes in place.
Now you will have time to remove the flappers and see what is going on while you can safely drive the car.
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Jackba
post Jul 18 2018, 02:15 PM
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QUOTE(Dave_Darling @ Jul 17 2018, 01:31 PM) *

One possibility is your mistaking burning oil for exhaust.... But CO is nothing to mess around with; at least get a detector and check what's coming into the car.

--DD

I believe that's what happened, Dave. Thanks for the suggestion.
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Jackba
post Jul 18 2018, 02:23 PM
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QUOTE(r_towle @ Jul 18 2018, 07:27 AM) *

Until you really want to fix it, which may take a while...
Remove the two rubber hoses that connect the flappers to the chassis tubes.
Grab two standard spray paint (rattle can) covers and put them over the tubes that lead into the chassis. The right ones fit like a glove.
Use a couple of large screw clamps that held the rubber tubes in place.
Now you will have time to remove the flappers and see what is going on while you can safely drive the car.


I discovered yesterday that there was sufficient tension on the heater box cables to allow heat to get into the cabin. I put slack in the cables so the flaps could close. As an extra measure, I removed the hoses. I'm going to be using the car for some events and it's certainly hot enough outside where I will not need a heater.
Your suggestion to cap the firewall tubes is a great one. Thank You!

Over the winter I'll pull the heat exchangers and do another pressure check.
Thanks everybody for all the help.
Jack
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