Good afternoon,

I am trying to determine if my heater core has a leak. After the heat has been on for a while, I think I can smell anitfreeze very faintly. It may just be mold or some crud heating up inside the evap box causing the smell, but I want to be sure.

Is there a good shadetree way of testing it?

-Im not seeing any coolant drips
-I have not noticed any loss of coolant in last 1k miles
-radiator is new, water pump is new, hoses are new, cooling system works well and holds ~85C just fine

If I understand the heater core correctly, it has two independent sides? So if my core has a leak the smell will only be emitted from either the passenger or drivers vent??

Thanks for the advice :-)

-dd

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'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

If you smell it from inside the car you have a leak . Afaik there is no shade tree test and it requires a dash pull to get it out. I have to do this on the wifes car, not to crazy about it... I have removed a dash 2x. You will find that a cordless drill will have mucho time.

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http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

I agree, if you smell it then you have a leak. When I replaced my heater core the leak was just a very slight dampness at one end of the core. Stunk like coolant when the heat was on though. Yes, the 123 heater core is difficult but its not the end of the world. Have the AC system evacuated and then go for it. My AC shop "kept" my R12 for me until I was ready for recharging. Just be patient, the job is tedious but not particularly difficult. There is lots of stuff under the dash in these cars. While you are in there check the vacuum pods and ACC control solenoids. I when back in to mine just to do the damned solenoids.... RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

Thanks for the replies guys.

Luckily, my dash is currently off for ACC pod repair. So Im partway there.

Im about to go outside and turn the car on and turn the heat on. Ill return in 20 minutes after leaving the car idling. If I smell coolant after having the car sealed up and running then its definitive. It was really, really faint before. I mean really faint.

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Don't forget to plug the oil line that runs to the gauge!

__________________
1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

Did some testing tonight and got the 'smell' to come back. After doing some comparative sniff tests between my interior and a bottle of zerex G-05, I have determined I dont have an antifreeze smell. Its just moldy/dirty smelling after the heating system warms up to operating temperature.

Gave it a shock dose of Lysol spray into the fresh air intakes to begin with. Now it smells like fresh linens...lets see if the stench returns.

Any tips on cleaning out the smell? I guess Ill do some searching. It almost is enough to make me want to take it all apart just to clean.

Thanks again for the help,
dd

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car

Why would you evac the r12?

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

To fully pull the evaporator box and replace the heater core or evaporator you have to de-charge the AC system since you need to disconnect the high pressure AC lines.

dmorrison talks about this in his wiki article that i have referenced repeatedly:
http://www.peachparts.com/Wikka/W123Evaporator

dd

__________________
-------------------------------
'85 300D, 'Lance',250k, ... winter beater (100k on franken-Frybrid 3 Valve Kit)
'82 300D, 'Tex', 228k body / 170k engine ... summer car
'83 300TD Cali Wagon 210k, wife's car