Running Warm?
First off, it's been in the 90's-100's in temperature lately.
-On Steep highway grades, the coolant gets close to being at the 100 degree C. line.
-In traffic stops, the needle creeps up, just about to the 100 degree line.
-After driving, and I turn the car off, if I leave the car on ACC mode, the coolant will get to the 100 degree line after the car is off.
On some cars I've owned, the electric fan motor goes on after driving to cool the engine once the car is off. Is that the case on the W124's? Should it be going on?
I've verified that the two accessory fans in front of the radiator do go on when the engine and AC is on.
I opened the coolant resevoir and it looked like there was fluid in there. It appeared to be clear liquid, not the colored stuff you usually find. Not sure who changed it last or what they put in.
Otherwise, the car is great. A/C is cold, all electrical accessories work fine and everything is original. Love the car, just don't want to ruin it with over heating/stressing the 18 year old beauty.
Thanks, your help is appreciated
As well,
100 is within the operational parameters designed for the engine. you should worry if its constantly in the 100s and edging towards 120.
in my car (i live in northridge) i run pretty much straight water in summer and if the level gets low (which it does as my car consumes water (slowly) and oil) towards winter i add anti freeze.
Thanks for the response.
Anyways, finally took it in and he said its the temp gauge thats faulty. He switched my instrument panel with another car and said it ran fine w/out overheating and drove with the A/C on. He even laser'd it or whatever and it wasn't overheating. I am waiting for the part to come in from ebay because the dealer wanted $1000 just for that small temp/gas/oil gauge. ridiculous i swear... so possibly something you might want to look into
I believe the electric fan has 2speed for 300e, check the fuse/relay on the fuse box, make sure the fuse is OK! If the fuse busted your electric fan only work in low speed, never go to second speed.
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100*C is 212*F (F* = what we here in the USA are used to). So, best thing to do is ALWAYS use a 50/50 mix (unless you live in frozen north) of Mercedes coolant and water. (Water Wetter does work to loew operating temp, I've run extensive tests).
Boiling Points & Pressures
Pressure Boiling - Temp. (Deg. F)
0psi - 212*F (100*C) Sea level
4psi - 224
7psi - 232
9psi - 237
13psi -246
14psi -249
Note: Boiling point drops with altitude. At 2,500 feet, water boils at 207 degrees; at 5,000 feet, 202 degrees; at 7,500 feet, 198 degrees; at 10,000 feet, 193 degrees. Sea-level atmospheric pressure is 14.7 psi. By contrast, at 10,000 feet, atmospheric pressure is 10.0 psi.
NEVER run straight water. Corrosion will KILL your engine.
A new radiator cap (20psi) is a good thing, as that will raise the boiling point a whole lot.
A new thermostat every 2-3 years is a good thing.
The electric fans are 2 speed. Low is ONLY for A/C operation.
High comes on ONLY when engine coolant temps get REALLY hot.
The mechanical fan clutch has a WHOLE lot to do with engine temp staying in the correct range.
Check it for proper operation, and change if not working properly.
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