I changed the fan clutch recently on my 104 engine (bearing bracket also). The very next day car started to overheat in trafic (did so before, but in the summer, not when its 40F outside !). Few days later the water pump was changed. Still overheating the same way.It looked like the fan clutch was not ingaging so the tech sugested new radiator . I instaled that, still no change ! Whent back to the shopp, the tech agreed to replace fan clutch again at no cost, but said that its probably the head gusket (?!) Can this be true? Can head gusket afect overheating?
In the past 3 weeks I instaled new fan clutch, bearing bracket, water pump and radiator, about $1,300 for cooling system and now I am looking "down the barrel" of aanother $1,500 please help !

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Dmitry
90' 300CE
17" Intra Signums
Brulen mufler
Euro Headlights/Clear Blinkers
White gouges (made my own)

The day after you changed the fan clutch it overheats, having not overheated before.

Then a new pump (with the suspect 'new' fan clutch?) is installed and it still overheats. "It looked like the fan clutch was not engaging, so the tech suggested a new radiator. I installed that, still no change!"

Hmmm, after it didn't look like the fan clutch was engaging and suggesting a new radiator, NOW the tech agrees to change the clutch but 'thinks' head gasket.

HOLD EVERYTHING RIGHT THERE!!!!!

First, have the tech explain how he will show you that the fan clutch is, or isn't, operating properly. Then, have him explain, slowly, how the radiator affects the clutch.

The clutch engages the fan to mover more air to cool the radiator. So, as the radiator heats up the clutch SHOULD engage. If it doesn't engage the fan can't cool the radiator. Why change the radiator??? If the fan and clutch are not operating properly have him change the clutch again at no charge. Repeat until YOU are satisfied that the fand and clutch are operating properly.

If this now keeps the car from overheating, tell him what he owes you for the water pump, radiator, brackets, etc..

If it still overheats, have him show you that the thermostat is NOT at fault. You didn't mention that it has been checked or changed.

A head gasket CAN result in overheating, and because I've had several let go in other cars I know that there are definite symptoms. Before you he even THINK about head gasket replacement insist that he show you some definite symptoms of head gasket failure such as bubbles in the coolant, excess coolant pressure without excessive temperature, or antifreeze in the oil. You might also want to get second opinion from another tech.

In my opinion he must do much more than just "think" it might be a head gasket. So far his "thinking" has been at your expense. If he has a problem explaining his diagnositic steps and reasoning in a way that you can understand, I'd suggest finding another technician for future work.

BCingU, Jim

If the cooling fluid level has not changed it's not a bad head gasket. If the head gasket was bad. You would have fluid lost.

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Mike

I replace the thermostat FIRST, without condition. After that, you can check the radiator by driving the car hard and then turning off the engine and putting your hand on the fins in front of the fan. If the radiator is hot, it is usually OK, the bad ones will have a cold spot somewhere...where the water is not flowing. Lastly the fan clutch. I have only seen them fail on the older cars thus far. Be sure the gauge is accurate and the aux fans work.


The head gasket could cause this, but it is a long shot. If the head gasket is a fault, the pressure inside the cooling system will be high.

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Benzmac:
Donnie Drummonds
ASE CERTIFIED MASTER AUTO TECHNICIAN
MERCEDES SPECIALIST 11 YRS

Please bear in mind the last paragraph in Jim's post. It speaks volumes. It sounds like your tech is "shooting from the hip"

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Scott Diener
89 300E
93 300E
92 Volvo 740 Wagon aka "Mutt mover"

Sorry guys , but I wasn't suspecting the tech, thus did not tell the hall story. I wanted to replace the water pump becouse it was rutling (bearing might have gone south) plus the "O" ring looked like a buble. As far as fan clutch, it was not stif and I could stop the fan with my fingers or spin it more than a few inches when engine is off. So all of those thoings I wanted to replace anyway. Radiator.... well, I don't know about that one. Few people besides the tech sugested to change it (as mentioned above, cloged radiator doesn't let hot air to the clutch). I did the work myself, so it was only the price of the radiator itself.
The tech will replace the clutch this weekend at no cost,
and I am hoping that will solve the problem. What woried me is that the tech was scheptical about the defective clutch and said thats it probably the head gusket. I am keeping my fingers crossed.
P.S. The termostat was changed a year ago.
Before all of this was done, when the car overheated in trafick, it took 10-20 seconds to cool once out of the jam. Now it takes couple of minutes if not longer to come down.

__________________
Dmitry
90' 300CE
17" Intra Signums
Brulen mufler
Euro Headlights/Clear Blinkers
White gouges (made my own)