I have a '89 300E 2.6 it had a coolant leak for a while so I took it to one mechanic and he said it was a freeze plug. He said I can put a can of block seal in it and it will be ok until I can afford to fix it. So I ran a couple different sealer through it but nothing stopped the leak. Another mechanic said it was the water pump, and he was right. It took me most of today to replace it but I got it done. Now there is a issue with it over heating. I put a new thermostat in it today also. I checked the hoses and there was a lot of pressure in the system, so I thought I will just take out the thermostat and then the coolant will circulate without the preasure. Even without the thermostat it is over heating and the preasure is still there. How could that be? Could it be the radiator got clogged from all that stuff I ran through it? Can this type of radiator be cleaned out at a radiator shop or do I need to get a new one? If you think that is the problem. Plese help [&:]

Dan

 

You need
the thermostat to slow the water flow down enough for the radiator to properly cool it.Most will run hotter without a tstat thenthey will with one.You can have some blockage just have the radiator properly flushed with chemical flush and pressure tested.Have you checked for combustion gases in the coolant to rule out a head gasket failure?
ohlord