Does your engine run hot?

Chances are that your thermostat is stuck or not working at all.

Time to replace it before you do further damage to your engine and run the risk of cooking your engine Mahle replacement unit.

Mahle is a quality European Brand and is an OEM manufacturer for Mercedes Benz.

This part will suit the following MB Vehicles:-

  • M121
  • R121 190SL


This kit is shown as no 41 in the diagram above


Original Part Nos:-



A121 200 05 15

121 200 05 15

121 200 0515



Mahle part number –  TX3 79D


Don’t not pay over $100 for a genuine part. Our price only $45.00

Please check you have the correct part number for your vehicle.


Most parts available for Mercedes models post 1945.


McStarparts – “Keeping classic Benz’s on the road.”

Mercedes M121 - 190SL Thermostat 79 deg C - 121 200 05 15, 1212000515

SKU: 121-200-05-15M
  • Available for immediate despatch

  • International buyers – please note: Import duties, taxes, and charges aren’t included in the item price or postage cost. These charges are the buyer's responsibility. Please check with your country's customs office to determine what these additional costs will be prior to bidding or buying.

"Keeping Classic Benz's On The Road"

Kevin McCarthy
+61 0418 634 080

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