Hello People,

well I have a 1995 E420, Very Smooth Car. The problem is the heating.
Yesterday ( 8/24/10 ) I changed the Thermostat and flushed the radiator
and did a 50/50 mixture of mercedes benz coolant and distilled water.

Well it seems to still heat a little too much. If I am on the freeway going 60mph+
the car will run at around 85 C. But if im in the city or im in traffic the car goes up to about 110 C. ( also once the car hits 110 C , the AUX fans kick in and the temperature starts to drop slowly. They both work fine) but thru the reservoir tank there is a escape hose and it starts throwing the hot water thru there. You can see the pictures. Im in Southern California, its about 103 F right now. that temperature is the highest ive seen so far. My concern is the water that is being thrown out. all hoses are fine, no leaks, no funny noises from the water pump or at all. The Fan clutch is working properly according to my mechanic.

All your guys input is greatly appreciated.

Thanks

Since your mechanical fan, and your electrical fans are working, I would suspect the cap itself. The spring could be worn out, but its probably the rubber seal that is getting old.
They are not expensive.

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

Also replace the hose on the "expansion tank" to the "overflow reservoir' in the fender. You have been overfilling the expansion tank, it gets hot and siphons but yours cant cause yours is missing the hose. When cold the fluid level should be around the crease at the top. 110 is not overheating in traffic. Aux fans dont even come on to 105. Viscous fan may be bad which may help a little, but radiator efficiency would be more likely. Its hot down there, anything less than 120 which is the red is ok thats why its red. Also outside temp says 118 on your dash, 10 degrees below that is awesome for your system.

@Larry Delor
Thanks I will check the Cap and maybe change the radiator if anything.

@macdrone

You are probably right. I ll try that and see what happends, my car is running fine, really smooth. It hasnt heated much anymore. Thanks

I'd say it's probably the fan clutch. I understand what your mechanic said, but unless he (or she) put a rag in the fan or dismantled it, then it could very well be the issue. You HAVE to put an OEM clutch back on (Sachs) - do not use BAER or other Asian clones.

2cd guess is the radiator itself. They're a surprisingly easy replacement, and even the aluminum overseas units will give you a few good years if you get past 2-3 days.

3rd/4th guess - Unresolved airlock in the block, pump is really bad though shows no outward signs, thermostat is blocking everything, plastic bags from road blocking air entrance, condenser grill clogged, serp belt slippage, etc. And like Larry said, if it's not pressurized then the boiling point rises dramatically, thus water will boil and clog system at heat-points before it can get back to radiator. Caps are cheap

Good luck -

The missing hose only directs burped out coolant to the ground. It has no effect on cooling. But you should replace it.
You should check/replace the pressure cap, and check the radiator and A/C condensor for impediments to airflow. If the coolant temperature rises above the level shown in your photo you should test/replace the thermostat.

Looking at the pictures, I remembered that I had to replace my expansion tank on my 94 E420 - the tank was leaking at the connection between the plastic, and the brass neck.

__________________
It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

i agree change the expansion tank and fit new radiator cap.if this doesn't totally fix it you are looking at a new radiator.check that engine fan with a rag on backside while engine running this will confirm good or bad fan clutch.

__________________
David S Poole
European Performance
Dallas, TX
4696880422

"Fortune favors the prepared mind"
1987 Mercedes Benz 420SEL
1988 Mercedes Benz 300TE (With new evaporator)
2000 Mercedes Benz C280
http://www.w108.org/gallery/albums/A...1159.thumb.jpg

That line should be connected to the overflow tank in the fender. The expansion tank holds pressure and siphons back and fourth to the overflow tank. Thats why the expansion tank should never be topppped off hot or cold or youll always end up with water on the ground from the overflow tank. When it gets hot and relieves some pressure (which is normal) it will sipphon back as it cools down. Just re run the line and I am sure youll be fine.

Again if its that hot outside your system is working like a champp.

Might want to replace the oil sending unit tho as if it reads zero (which is normal when the unit goes bad or the lower wiring harness goes bad) But if ppressure was zero your engine would probably start knocking and lock up by now with that heat I am sure its sensor or wire grounded out.