Mercedes 190 E overheating - again

[smallcowsheep]

You all very kindly (or maybe it was another load of Mercedes guys) anyway Someone helped us a lot with a problem we were having with my son's 190 E (1995). It was overheating when he first got it and we've checked waterpump, thermostat, backflushed rad. etc. Waterpump and thermostat are new maybe indicating this is long standing problem. Backflushing rad. etc seemed to cure it tho' it always ran v hot but not boiling. Now it is boiling again despite more backflushing. The backflushing proves there is a connection all through rad since it comes out top but when my husband just ran it up the hill it was boiling at the top of the rad but cold water coming out when tap opened. Surely this means rad is kaput? Previous replies suggested head gasket but there is absolutely no sign of water in oil after a month and the engine runs sweet as a nut.

Sorry this is such a long whinge but my son is not having a good time at the moment and I feel so sorry for him!

 

[GEORGEROV]

You are not getting flow through the radiator so either the pump is u/s, thermostat u/s or more likely you have an air lock in the system. Try pressing the various hoses in the cooling system to squeeze out the air. If this still doesn't work remove the thermostat and try it then.