Dave300e

Hi I am trying to get my 88 300e to run normal and not overheat into the red... If left to idle the engine will overheat and the coolant in the expansion tank will shoot coolant through a open plastic spout out the side just below the radiator cap.. is this opening that faces the front supposed to be there? right now only 2 hoses atached to this plastic tank. One that goes to the top of the radiator and the other to the bottom... Once the engine gets hot steam and noise comes from this plastic tank then a strong stream of water jets out the side..doesnt seam right.cant find any hoses mising from the radiator no leaks from the rad seen... replaced the radiator cap and thermostat. Also noticed that no water seams to flow to the top hose when the bleed screw on the thermostat housing is loosened. If i remove the thermostat and fill with water and start the engine I should see the water shoot out if the water pump is good or is there an easier way to test.that. any ideas David...

AMG_Eric

head gasket is gone. you wont see water because the water boils off out of your tail pipe. i just had mine done because water would shoot out the overflow.

it could also be a bad thermostat.

NorCal124

There should be a 3rd (possibly clear looking) hose from that spout underneath the radiator cap. That hose is supposed to exit somewhere under the front passenger wheel well. As far as your coolant evaporating all the time, I'm clueless.

Dave300e

Looks like someone changed the order of the hoses to this tank! as I have discovered that the one spout open is supposed to have the return line connected back to the rad. The other close to the rad cap goes back to the wheel well. Just this change alone caused the engine to overheat to the red gauge. ..Oil change and fresh coolant on the order...Thanks for all your help....Dave

mhorn

The line you are missing goes to an overflow tank in the back wheel well area.