These v-8's are difficult to purge correctly. Have them replace the thermostat again, just to be sure they have a good part in the car. Now there is a tool called an Airlift. This thing will vacuum all of the air out; then suck coolant into the void. This will get all of the air out of the engine.

Be sure the auxillary fans are working.

------------------
Benzmac:
Donnie Drummonds
1991 GMC Syclone
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM