Hello all,

1999 ML430, 217,436 miles. I live in Chicagoland and I have been smelling faint antifreeze with heat on this winter.

Friend with similar smell on 1999 Subie Legacy Outback just blew head gasket, (although she was leaking antifreeze onto ground and changed water pump and thermostat prior), I am hoping I don't have the same future in store!

I am not leaking any antifreeze and I have not noticed a change in level in coolant reservoir. I drained/refilled radiator and engine block this past summer. I have not changed hoses, but they are not soft or bulging around clamps. Original water pump and thermostat still on truck.

Thanks for any help.

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1999 ML430
2003 Chevy Suburban Z71
1993 Honda Prelude V-Tech

Have replaced several heater cores in ML's for that reason. Most likely your issue as well.

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MERCEDES Benz Master Guild Technician (6 TIMES)
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Retired Moderator

Concur, that would be my first place to check.

Jim W.

Thanks Gentlemen,

I will look into this. How hard of a DIY is replacing the heater core? How much time do I have and worst-case scenario?

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1999 ML430
2003 Chevy Suburban Z71
1993 Honda Prelude V-Tech

Discovered the problem.

Awhile back I cracked off a nice portion of the fan shroud right next to the top radiator hose on accident. Decided to examine the top hose last week after I noticed fluid leaking in the garage and discovered that a sharp piece of shroud that was left had cut into the hose. The smell was comiong from dripping coolant burning on the radiator while driving!

After replacing top and bottom hoses this past weekend, I have not smelled anymore coolant while the heat has been on.

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1999 ML430
2003 Chevy Suburban Z71
1993 Honda Prelude V-Tech

You certainly dodged a big bullet; heater core leaks typically require the dash and center console to be removed.