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I believe I may have a leaking heater core, as I can't get rid of a slight coolant fluid smell (sweet maple syrup) in the cabin when using the heater.
I've checked the forums and other places to make sure it's not a problem elsewhere in the engine cabin and I recently just replaced the radiator (which is now operating in tip top shape). The smell existed before I did the replacement.
From what I can see in the service manual, it looks to be a pretty intense process having to disassemble the entire steering column and dashboard to get to the HVAC unit itself where the heater and evaporator core are located.
Before I go down this route, wanted to see if anyone had any tips or advice on things to check. As well as any tips / tricks on doing the replacement itself.
Have you changed and clean the cabin filter? The core shouldn't go out, if your not seeing any coolant inside the cabin that's not the problem.
Did you drive through any large amounts of water? Puddles? Do you have rust on your car that could cause leaks?
Cabin filter was replaced about a month ago. Don’t recall driving through any large puddles of water recently and no leaks due to rusting that I’m aware of, or that the local dealer detected when I took it to them for an inspection after it was purchased.
Maybe there’s some dried up radiator fluid somewhere in the engine area due to the radiator leak it had prior to the replacement I did last week? Where does the cabin get it’s fresh air intake when not in recycle mode?
Also, I ran a full pressure test on the cooling system and it maintained 16psi for the entire hour that I left the pressure testing kit attached and pressurized. So even if there was a small leak, it should have allowed some of the pressure to go down after an hour.
If it had leaks before that you fixed or had fixed, if I were you I would clean the entire engine bay then do a good under car wash. See if that helps before trying to replace things.
So I just finished doing a thorough engine bay cleaning. And just a few minutes ago I went to check the cabin floor, and sure enough....found the leak. small drip to the right of the gas pedal See pic below...
I have the service manual and have read through the entire process. So I'm aware it requires removing the entire dashboard, steering column and having to cycle out the AC refrigerant (since it requires disconnecting the AC line). So I know it's not an easy job, which is the reason I asked to see if anyone had done it yet, and had any tips / advice.
I just spent the last month performing the following all DIY:
replaced the starter
replaced the radiator
flushed power steering fluid
replaced the weather striping on all 4 windows (huge process requiring removing the entire window glass from each door),
replaced all 10 speakers (requiring tearing down the entire rear to get to the sub)
installed NOICO vibration and sound proofing on all doors and rear cabin area
replaced the amp & radio unit
replaced all exterior / interior lighting with LEDs (yes, ALL lighting except the normal HIDs)
installed the leather shifter head (which requires tearing the entire center console and shifter)
I'm about to replace the steering wheel with a new one
So Im pretty comfortable at this point removing the entire dashboard and breaking down the HVAC unit to get to the heater and evaporator core. My biggest concern is handling the AC refrigerant. I don't have the equipment or experience in doing that. Is it something I can just take to a shop, have them drain it out, bring the car home, do the repair/replacement on the core and then bring it back to a shop to refill the the AC refrigerant?
Last edited by holografique; 02-15-2020 at 09:50 PM.
So after watching this video of someone removing the entire dashboard on a 3G TL (I know, not the same car, but similar enough), this is definitely not a one-man job and not something I think I have the time for.
Yeah, it sucks man that's why I was seeing if you could see that if it was the heater core itself or not. Do you get any hot air?
Yea, I mean with the time (and help) Im sure I could do it. But with a normal day job, etc, I easily see it being a multi-week job for me, and cant have the car in the garage sitting that long (1 car household at the moment).
The heater is working, and the leak/smell appears to intensify when the HVAC mode is set to any of the modes with the floor setting. For now we're keeping it in manual with only the upper air vent mode activated.
To my knowledge, the heater core is the only component internal to the cabin that has radiator fluid going through it. So it has to be the heater core. And the leak is directly in the bottom left corner where the heater core sits in the blower unit (according to the diagram below).
I tried to respond once before but the site was acting strangely. Before I pulled the IP to swap the core I would absolutely try Bar's Leaks or something similar. IMO you don't have much to lose insofar as if it doesn't work you'll be doing drain/fill already, easy enough to add a flush step if you felt necessary.
Everything I've read says not to use any type of agents or additives to block a leak at risk of short/long term damage to the coolant system. Not work the risk IMO, only to have to spend more money down the road.
I bit the bullet and brought it to the dealer. All fixed (with confidence)
02-15-2020, 08:01 AM
