Antifreeze smell

[7825th]

When I turn on the A/C in my '78, I get a slight smell of
antifreeze in the cockpit. The heater core is dry, hoses & clamps have been double checked & are fine. No leaks from the engine area & no drips on floor - this is annoying as hell.
Anybody have any clues ? Thanks.
I FORGOT TO MENTION THAT MY MECHANIC VERIFIED THAT THE CORE WAS DRY !

 

[78SilvAnniv]

If you can smell it, you must have a leak somewhere. I would suspect the core, as it is positioned closest to the duct work for the air system. Perhaps this is a tiny pinhole leak? How were you able to determine the heater core was dry?

I wish you luck, we changed the heater core on ours 2 years ago. Husband invented many colorful words.
Heidi

 

[photovette]

I agree--it starts off as a slight smell--it'll end up as a flood--change it now while it's still cool in the mornings. Plan about 6 hours. Take it in for an estimate first; when they tell you how much they'll charge for it, you'll be happy to dig right in yourself.

 

[Jack]

I agree with the others ... change it/inspect it now. If you cannot do it now ... strongly suggest you bypass the heater's water circuit ... run a length of heater hose from water pump nipple to nipple on intake manifold ... this will prevent further/more leaks into ductwork/carpet. In another car, I had a core bust wide open while driving at speed ... instantly & totally fogged windshield ... scarey!
JACK:gap

 

[78SilvAnniv]

I had a core bust wide open while driving at speed...

That is what happened with me and the 78, but it was summer driving with the windows down that prevented me from smelling the telltale antifreeze smell before it was too late. I had the green flood in the passenger footwell.
The only saving grace was I was less than 3 miles from home and was able to limp back at low speed to keep from overheating the engine.
Heidi

 

[Smokie Joe]

anti freeze smell

Hey my first post.I just discovered the vette I recently bought has a leaking heater core.Pulled the floor mat up,and noticed the green stain in the carpet.I think I'll do the hose bypass,and then of course time for new carpet.My question is once I rip the carpet out,what should I do to clean up the anti freeze residue left on the floor pan?

 

[jdp6000]

A member sent me this a while back. I changed my heater core. It really wasn't that tough. You also get the chance to clean up a lot of parts as you go along. Skip the seat removal...it wasn't necessary.

1981 Corvette Heater core replacement with Air Conditioning.

A step by step of how to remove and replace the heater core.

DISCLAIMER: This is how it went on MY 81. Screw sizes may vary, procedure may be different for non air con cars or for your 81 but I doubt it. I wrote this up to try to help others who may have this problem. When people say the vette was built around the heater core……they are NOT kidding.

1) Buy lots of cold beer, don’t forget this one it’s important.
2) Drain coolant from car.
3) If you’ve got T-Tops remove them.
4) Remove passenger seat, two ½ inch bolts on rear rails, two ½ inch bolts on front rails. Remove seat.
5) Remove carpet tack rail from left side bottom of body on passenger side, 4 screws.
6) Remove inside passenger kick panel, 1 screw.
7) Remove glove box insert, 2 screws on top, 2 screws on bottom all inside the glove box.
8) Remove parking brake arm rest cover.
9) Remove passenger and driver side center console knee rest panels, 4 screws in each.
10) Peel back passenger side carpet.
11) Place rags or an old sheet on flooring under dash to catch all the debris ( easier clean up)
12) Remove center console shifter cover screws to free the plate, 4 screws, 2 on each side, do not remove it.
13) Remove center console gauge plate, 2 screws on top, 2 screws on side. After these 4 screws are removed, look under the center console plate, where the center console and gauge plates mate, there are 2 screws that attach them together, remove those two screws to separate the plates, 1 on drivers side, 1 on passenger side.
14) Gently pull gauge plate forward from the top of the dash and reach behind and disconnect the plug to the panel, top third of panel is where the plug is located.
15) Remove gauge plate from car. NOTE ( I pulled mine to one side, left the radio wired and laid it on the drivers side foot compartment, you may be able to bungi cord it the steering wheel if the cables are not long enough but it needs to be out of the way of the dash opening that was created by it’s removal)
16) Remove 2 dash retainer screws on passenger side of dash ( far left side of dash board) Word of CAUTION here: The passenger side of the dash will now be hanging loose any excess pressure on this may break the dash so pay particular attention to torquing the dash especially in the later steps while you have your arm thorough the glove box hole.
17) In center console “hole” remove duct work
18) Under passenger side feet area remove duct work.
19) You should now have only one piece of duct work left and a huge mess on your hands. Now comes the fun part.
20) Jack up passenger side of car, slide under the car and CUT the hoses to the heater core just below the heater core pipe stubs. IF you plan to reuse the hoses ( I DO NOT RECOMMEND you do that, change them while you’re this far in!!) then just disconnect the hoses………….good luck, I couldn’t do it.
21) Remove hose clamps ( not absolutely needed but made my life much easier getting the core out of the car)
22) Back inside the passenger compartment, remove all mount bolts on the remaining duct work, 2 bottom, 1 top.
23) Remove the heater control mechanism plate, 3 5/16 screws, 2 front, 1 behind. The rear one is hard to get to and I left it until I dropped the duct, after step 27.
24) To disconnect the cable, using a screwdriver, pry slide the retainer up the shaft and then slide the cable up the shaft.
25) Disconnect all vacuum lines to the top of the mech plate.
26) The entire duct is now disconnected from the inside of the car but has one more bolt in the engine compartment that needs to be taken off to release it from the fire wall.
27) Engine compartment, passenger side. Looking down on fire wall behind where the duct work was there is a bolt with a not sticking out of the fire wall. With air conditioning this “appears” to be holding the plastic housing to the fire wall but the actual stud is part of the duct work inside the car. Remove the nut from the stud.
28) Back inside the car pull the duct work back toward the rear of the car and then push up and tilt back toward you, again push up and continue this motion until the duct is free. Once free there is one more vacuum line to disconnect off the main vacuum pump on the duct.
29) Carefully rotate the duct counterclockwise to remove it from under the dash and voila, the duct and core is removed from the car.
30) Cut away or remove any access hosing that was left on the core.
31) Remove retainer screw that holds plate assembly and hose stubs. Remove retainer plate.
32) Slide the rubber grommet off the hose stubs.
33) Remove screws, 4 total, from under the gasket material on duct. You can identify the screw location, 5/16 heads, by looking at the other side of the flange and locate the screw holes.
34) Remove back cover of duct.
35) Remove heater core from duct and replace.
36) Reassembly in reverse order.

 

[Jack]

Hey my first post.I just discovered the vette I recently bought has a leaking heater core.Pulled the floor mat up,and noticed the green stain in the carpet.I think I'll do the hose bypass,and then of course time for new carpet.My question is once I rip the carpet out,what should I do to clean up the anti freeze residue left on the floor pan?

Soap & Water will clean up the floor pans.
Antifreeze alone doesn't "ruin" the carpets. If yours just need a good cleaning ... pull em out carefully ... lay em on a picnic table etc ... use a good strong garden hose and wash em with dish soap & water & a brush ... drip dry. Car dealers do this ALL the time. If your carpets aren't fragile or prone to rip/fray ... you can use a pressure washer ... again, car dealer stuff.
JACK:gap

 

[Smokie Joe]

anti-freeze smell

Jack,
Thanks for the reply.I think that I will give the carpet
cleaning a try.Got nothing to lose by trying,and that will
free up some money to fix some of the other things that I need to do.Appreciate your help.Now if I can just figure out how to add those real cool smilies.

 

[Jack]

don't trust temp gage if coolant low

The only saving grace was I was less than 3 miles from home and was able to limp back at low speed to keep from overheating the engine. Heidi

AFAIK, most C3's have eng temp sensor(s) in head(s) ... MANY other cars are same. If there's a leak ... or for whatever reason the coolant level drops below sensor ... the sensor is no longer dipping into coolant and is surrounded by only hot air/steam ... and it cannot sense "real" temp. Motor can be hotternhell but sensor doesn't see it ... gage/light may read normal or even a bit low ... while motor cooks. Example: driver takes car to shop to replace busted rad hose ... mechanic says "hope you didn't overheat & ruin it"... driver replies "oh, I watched the gage/light and it never went red" ... before the week is out, driver returns to shop complaining of rattling/smoking/blown head gasket etc etc. Best not to rely on temp gage/light if coolant drops below temp sensor.
JACK:gap

 

[78SilvAnniv]

... the sensor is no longer dipping into coolant and is surrounded by only hot air/steam ... and it cannot sense "real" temp. Motor can be hotternhell but sensor doesn't see it ... gage/light may read normal or even a bit low ... while motor cooks.
Best not to rely on temp gage/light if coolant drops below temp sensor.

If I tried to drive hwy speed the temp climbed rapidly, when I slowed to 40 or below it remained at it's normal operating temp. Maybe mine was indicating what you described above?
Makes not much difference, we did rebuild the engine this past summer. My heater core flood occured about 3 years ago in summer.
h

 

[Mr. Chuck]

My 81 had anti-freeze smell, heater core found to be the source; as others have said, it starts with pin hole(s) and will only get worst. I also found that air inside car carrys little droplettes of anti-freeze, that coats inside of all interior glass which fogs up when the outside temp goes down. The only way to get rid of the fog is to remove the anti-freeze leak and several passes of windex to remove film on glass. The fogging really becomes a safety hazard, as well as the anti-freeze odor which can be toxic if you have to run with the windows up in cold weather.

 

[bossvette]

I have heard it said that the heater core is put in first ant then they assemble the Vette around it.

Thats why so many C3's are fair weather cars its easier to block off the coolant lines then to replace the heater core.

 

[Mr. Chuck]

My experience with my 81 is that a local auto repair shop was able to complete the job in one work day and cost about $350, true most of the cost was labor, which at the time was around $50/hr. I had at first some success in stopping the leak by using some of the pellet type of raditor stop leak which I was able to see sealent at leak points after the core was removed. I had previously used the same shop to replace the radiator with very good results.