Please help & comment:

I am looking to buy a 1993 (W124) 300E w/87k on it. When checking it out I found that the AC worked great, BUT the HEAT would not come on anyway/anyhow.
The thermostat was hot. I also messed around with all of the CC controls. I also checked all fuses.

What are the next primary things to check (i.e. Heater Valve?)?


The owner claims that the heat was working perfect earlier this week...

Thank you in advance.

Kieran-

__________________
Kieran K
Jersey Shore
1988 300CE (for sale, AUG. 2013)
1995 SL320 (88K) - terrific car
1983 300CD
-1993 400E (sold w/74k)
-1988 560SEL (sold w/49k)
- 1995 S420 (sold w/75k)
- 2005 E320 CDI (sold)
- 2007 E350 4M (sold)
- 1984 300D, sold w/305k, CA car, zero rust & over $12k invested
- 2001 E55 AMG (sold w/81k), I really miss it.
- 1982 300CD (sold, all stripped down)

Recirculation pump possibly? Its in the engine bay below the coolant reservoir, its a tiny bugger. Make sure the tubes are warm and that its pumping hot coolant to your heater core.

Would the fan come on, but the air was cold, or did it just do nothing at all?

If nothing at all, I'd look into the cold engine lock. Basically the climate control has a separate temperature sender on the thermostat housing (there are three there...) that tells it when the coolant is warm enough to turn on the heater. In my experience these usually fail on, so the heater comes on too soon and blows cold air on your toes.

If the fan came on and blew air out the footwells, but was not warm, then I would check the coolant level to see if it is low. Also look into a potential problem with the heater valve. Disconnecting power to the heater valve normally permits full heat, so removing the connector from the valve makes for a quick test.

You'll get heat without an operating recirculate pump, just not quite as much of it.

- JimY

Great help guys, thank you.

* I do get AIR blowing - just not any warm/hot air (whatsoever...).

__________________
Kieran K
Jersey Shore
1988 300CE (for sale, AUG. 2013)
1995 SL320 (88K) - terrific car
1983 300CD
-1993 400E (sold w/74k)
-1988 560SEL (sold w/49k)
- 1995 S420 (sold w/75k)
- 2005 E320 CDI (sold)
- 2007 E350 4M (sold)
- 1984 300D, sold w/305k, CA car, zero rust & over $12k invested
- 2001 E55 AMG (sold w/81k), I really miss it.
- 1982 300CD (sold, all stripped down)

If this car had a production date of 10/92 (1993 300E), would the engine be the M103 or M104 series?

Thanks in advance.

__________________
Kieran K
Jersey Shore
1988 300CE (for sale, AUG. 2013)
1995 SL320 (88K) - terrific car
1983 300CD
-1993 400E (sold w/74k)
-1988 560SEL (sold w/49k)
- 1995 S420 (sold w/75k)
- 2005 E320 CDI (sold)
- 2007 E350 4M (sold)
- 1984 300D, sold w/305k, CA car, zero rust & over $12k invested
- 2001 E55 AMG (sold w/81k), I really miss it.
- 1982 300CD (sold, all stripped down)

I believe all 1993s (except 4matics) were M104.