Coolant Smell in Cabin - Benzworld.org

cqlink · 11-03-2006, 04:21 AM

Any thoughts on what could be the root cause of a coolant smell in the passenger compartment? My guess is a bad hose from engine through / to heater core(?)

Heater works fine. No water on cabin (that I could find - planning on checking again).

If it's a bad hose, can someone point out where it is? Tried looking under the hood. Nothing obvious running through the firewall.

300se126 · 11-03-2006, 04:38 AM

If coolant is leaking onto the exhaust, you will definitely smell it - check all of the hoses, and any other places near the exhaust line.

Eric@StarSuzuki · 11-03-2006, 04:47 AM

In my experience, most likely a leak from the heater core itself. Though the hoses do go bad as well. Hoses usually leak coolant on the floor, and on some cars the piping from the heater core goes through the firewall into the engine compartment and the rubber hoses are entirely outside the passenger compartment. I'm not sure about the 126 heating system, but I'd be surprised if there was rubber hoses in the passenger compartment. In any case, the rubber is never in the airstream for the HVAC system, so if you smell coolant, or if you're getting some coolant colored fog on the inside of the windshield, it's most likely the heater core itself.

cqlink · 11-03-2006, 08:49 AM

No coolant colored fog on glass. Will double check but no coolant on carpet. That's why I'm a little confused. Will try to look at hoses by exhaust. Was wondering about location.

talbir · 11-03-2006, 10:26 AM

The most likely place is where the heater pipes connect to the rubber hoses that in turn connect to the block.

In the engine compartment, beside the wiper motr, you will see three rubber hoses connected to the heater core metal pipes - they have clips on to secure them. Check there for leaks. When you park the car, you should see the water trickle, onto the transmission and onto the floor.

talbir

cqlink · 11-03-2006, 12:17 PM

Thanks. Haven't noticed anything on floor - just the smell inside passenger cabin. Checking hoses this weekend.

maybach.5 · 11-05-2006, 02:43 AM

I had a similar thing a while back on a '84 500SEL - coolant smell, but heater core seemed intact. Turned out to be the aluminum heater under the windshield, which heats the resting place of the wipers. At least the 500s have this feature - I do not know, which model you own and if you have it as well.

cqlink · 11-05-2006, 05:41 AM

Thanks. What does it look like? Will check today.