coolant smell when defroster is on
coolant smell when defroster is on
Hi guys,
I dont know exactly what is wrong with my car but I have been noticing a coolant smell when the defroster is turned on. It also fogs up instead of de-fogging. So, I am assuming that I have a coolant leak somewhere that is feeding into the heater system and being blown into the car somehow, but dont know exactly where to start looking. I recently replaced the radiator and thermostat and started noticing it then, but it could've already been happening, just not so noticeably - its getting worse. Any suggestions would be highly appreciated. Oh, and its a 92 RS with a 305 TBI, if that makes any difference.
Thanks!
I dont know exactly what is wrong with my car but I have been noticing a coolant smell when the defroster is turned on. It also fogs up instead of de-fogging. So, I am assuming that I have a coolant leak somewhere that is feeding into the heater system and being blown into the car somehow, but dont know exactly where to start looking. I recently replaced the radiator and thermostat and started noticing it then, but it could've already been happening, just not so noticeably - its getting worse. Any suggestions would be highly appreciated. Oh, and its a 92 RS with a 305 TBI, if that makes any difference.
Thanks!
Last edited by kreature667; Apr 27, 2009 at 10:14 PM.
Supreme Member
Joined: Apr 2006
Posts: 1,206
Likes: 4
From: Morganton, NC
Car: '92 T/A WS6 Vert/1956 Chevy Nomad
Engine: 350 TPI
Transmission: 700r4 w/ Transgo Kit
Axle/Gears: 3.42 LSD
Re: coolant smell when defroster is on
Classic heater core failure symptoms. It is a ROYAL PITA to replace. But there's lots of info on here on how to do it. I did mine last summer. Good news is, heater cores are cheap! Have fun, and get to work!
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Joined: Feb 2006
Posts: 1,093
Likes: 0
From: western ny
Car: '82 formula clone, 95 saab 900se
Engine: 350 vortec'd tbi, 2.0L turbo
Transmission: 700r4, 5 spd
Axle/Gears: 10 bolt 2.77 open
Re: coolant smell when defroster is on
x2, what a pain! i replaced the core in my '82 when i had the whole interior apart, not because it needed it, but because it was convenient to do at the time!
Re: coolant smell when defroster is on
that sounds horrible! Is there any chance it could be something else? The heater itself still seems to work, but if that what it is i guess i better get to it......thanks guys
Member
iTrader: (2)
Joined: Nov 2006
Posts: 148
Likes: 1
From: San Angelo, Texas
Car: 89 Iroc
Engine: 350
Transmission: T56
Axle/Gears: 3.70 9bolt
Re: coolant smell when defroster is on
Depending how good you are a contorting your body you can change the heater core without removing the dash. I did it in about an hour but I did not put the top screw back into the cover. Take your hand and run it around the top of the actual heater core cover after you remove the passenger side lower dash cover and your will find what I am talking about. once again if you can't get to that then it becomes a real PITA.
Semper Fi
Semper Fi
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iTrader: (3)
Joined: Feb 2006
Posts: 1,093
Likes: 0
From: western ny
Car: '82 formula clone, 95 saab 900se
Engine: 350 vortec'd tbi, 2.0L turbo
Transmission: 700r4, 5 spd
Axle/Gears: 10 bolt 2.77 open
Re: coolant smell when defroster is on
not much of a chance of it being anything else, you could try adding some bar's leaks to your coolant, but that stuff is a little sketchy. or you could just bypass your heater core until you have the time to fix it, but you won't have heat.
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Junior Member
Joined: Apr 2009
Posts: 8
Likes: 0
From: Northern VA
Car: 1988 IROC Z/28
Engine: 5.7 TPI
Axle/Gears: 3.23
Re: coolant smell when defroster is on
If your passenger side floorboard is not full of coolant it soon will be.
When you go for the hard screw use a box-end wrench and not the socket.
When you go for the hard screw use a box-end wrench and not the socket.
Supreme Member
Joined: Apr 2006
Posts: 1,206
Likes: 4
From: Morganton, NC
Car: '92 T/A WS6 Vert/1956 Chevy Nomad
Engine: 350 TPI
Transmission: 700r4 w/ Transgo Kit
Axle/Gears: 3.42 LSD
Re: coolant smell when defroster is on
1) Do NOT do any kind of stop-leak. It probably won't work, and even if it does it will only postpone the inevitable. Plus, it turns your coolant into nasty gray crap.
2) Don't be scared of it. You don't need to take the whole dash off, just the dash cap. That's only about eight or so hex-head screws and a little finesse (don't force anything).
3) You need to act NOW before your passenger floor ends up full of coolant. Bypassing would be the easiest option for you right now, but keep in mind it will eventually need to be fixed. It's summer, you don't need a heater. Just disconnect the two heater hoses running into the firewall on the passenger side, get a connector and a couple of clamps for a couple of bucks, and splice them together.
2) Don't be scared of it. You don't need to take the whole dash off, just the dash cap. That's only about eight or so hex-head screws and a little finesse (don't force anything).
3) You need to act NOW before your passenger floor ends up full of coolant. Bypassing would be the easiest option for you right now, but keep in mind it will eventually need to be fixed. It's summer, you don't need a heater. Just disconnect the two heater hoses running into the firewall on the passenger side, get a connector and a couple of clamps for a couple of bucks, and splice them together.
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Joined: Jul 1999
Posts: 853
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From: Everett, MA . USA
Car: 89 FORMULA FIREBIRD, 86 CHEVY CAMARO
Engine: L98, LB9 RESPECTIVLY
Transmission: 700 R4 (BOTH)
Re: coolant smell when defroster is on
A flexible shaft nutdriver with a 7 mm socket will help, also remove the ecm and put it out of harms way, this will give you more room to work the cover screws.
Senior Member
Joined: Mar 2009
Posts: 429
Likes: 0
From: South Suburbs of Chicago
Car: 89 RS
Engine: 2.8
Transmission: Auto
Re: coolant smell when defroster is on
Well if you don't know what a boxed end wrench is... You may need a little help with this job. One side is open ended and the other side is enclosed. I am sure you have a set of them in your tool box.
Joined: Aug 2006
Posts: 12,804
Likes: 103
From: Central NJ
Car: 86 Trans Am
Engine: 408 stroker sbc
Transmission: TKO600
Axle/Gears: Moser full floater m9, 3:70 trutrac
Re: coolant smell when defroster is on
its really not as hard as you guys make it out to be to change a heater core. A small 1/4" ratchet will be a lot of help for getting at the 1 screw that behind the map pocket.
Senior Member
Joined: Mar 2009
Posts: 429
Likes: 0
From: South Suburbs of Chicago
Car: 89 RS
Engine: 2.8
Transmission: Auto
Re: coolant smell when defroster is on
86 TA is right. Its really not that hard. You just have to take your time and dont force anything. There is always that 1 screw or bolt that you miss and if you try to force the issue you could easily break something.
Re: coolant smell when defroster is on
Member
iTrader: (2)
Joined: Nov 2006
Posts: 148
Likes: 1
From: San Angelo, Texas
Car: 89 Iroc
Engine: 350
Transmission: T56
Axle/Gears: 3.70 9bolt
Re: coolant smell when defroster is on
Good Luck,
GC Garner is right also about the dash pad. You don't need it off if you can reach the top bolt without having to, other than that its just a task so be easy and patient.
Semper Fi
Lthrneck
GC Garner is right also about the dash pad. You don't need it off if you can reach the top bolt without having to, other than that its just a task so be easy and patient.
Semper Fi
Lthrneck
On Probation


Joined: Apr 2007
Posts: 1,592
Likes: 18
From: Syracuse NY
Car: 84 Z-28
Engine: 305 HO
Transmission: r-700
Axle/Gears: 3:73
Re: coolant smell when defroster is on
You don't have to take the top of the dash out or drop the heater/ac box
down either !!!!!!!!!!!!!!!!!
Just take off the lower hush panel cover on the bottom of the dash.
Look at the face of the heater/ac box (passenger side). There is a little
door/plate on the face. Remove screws and there it is!!!!!!!!!!
Easy to figure from there!
down either !!!!!!!!!!!!!!!!!
Just take off the lower hush panel cover on the bottom of the dash.
Look at the face of the heater/ac box (passenger side). There is a little
door/plate on the face. Remove screws and there it is!!!!!!!!!!
Easy to figure from there!
Re: coolant smell when defroster is on
OK, well I couldnt reach the bolt so I now have the interior in pieces. But I got to the heater core today and you guys were right, that is definitly the source of the leak. Anyway, in trying to remove the bracket holding the core in a very flimsy tab snapped off. It seemed to interact with the moving insulating pads which seem to serve the purpose of ducting hot or cold air. So, I'm including some pics to show you guys. I am a bit worried that I broke something vital and dont want to find out after I put the entire dash back together. Anyone have ay ideas?






Re: coolant smell when defroster is on
Hey Kreature. Kinda hard to tell from the pics, but I'm pretty sure that's the same piece I managed to break on mine the first time I replaced the core. On mine, it was the plastic piece that supports the flapper door/hinge pin deal. I was so pissed when that happened! Anyways, I lucked out at the boneyard. There was a 3rd gen sitting there that the whole dash area was almost completely gutted except for the heater box area. All I had to do was remove the core cover, the core itself, and then remove that plastic plate that broke on mine. Not sure if you broke the exact same piece, but if you did, just scrounge one up at a junkyard.
Re: coolant smell when defroster is on
Hey thanks. Yeah, it was some little tiny frail flap thingy. I was so sick of dealing with the mess that I just put it all back in without that little flap. The car hasnt exploded yet, so I htink its fine
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