Sorry, Paul, but that's not true. Low speed aux fans only come on when refrigerant pressure is above the set point. On my M119, aux fans generally do not come on when ambient temps are below 80 degrees F even with AC on.

I'm with buckwheat - I would wonder about how "good" the water pump is. They are known to have impeller problems, so they can still pump coolant but not as efficiently as they should. As I recall, this is a particular problem with aftermarket pumps, but even OE ones can eventually wear.

The fact that coolant temps are getting to the point that they are really seems to point to inadequate coolant circulation.

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Steve
'93 400E

Check your T-stat. Just because it is new does NOT mean that it is good. Some of them fail quickly, some are even bad right out of the box!

Good luck.

I just bled the air from the system because I heard some gurgling when I put the heater on the other night. The fan clutch did engage because I heard it and could feel it. It came on and went off and it didn't seem to be dependant on engine speed. I don't know the reason to this.

I'll drive around today and see what happens.

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1994 E420, Pearl Black/Black. 2.82 rear diff., AMG front spoiler, painted lower half. SOLD

1972 & 1974 BMW 2002tii's.

I'm surprised....nay, astonished that your mpg isn't over 20.

At first I was going to say that your aux fan resistor is probably bad (a common low $ item). But it sounds like you might have that fixed. There isn't anyway that you mounted the fan blades on backwards, is there? (just stabbin in the dark here).

I'd check my fan for you, but my E420 is in the shop with the computer equivalent of a mental breakdown.

I did have to replace my cap, and a year later the reservoir itself, as it sprung a leak around the neck, where the plastic meets the brass.

Oh, my temp rarely gets to 100, and last month, I had a hard time getting it to 80.

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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

DCraig,

Any news about your E420? I just bought a 1994 E420 and noticed, while it stays cool enough in 90F weather, the fan clutch doesn't spin freely when cold, and that there is some kind of thread wound behind the clutch and jammed between the pulley. This may have been the previous owners cheap fix for an old fan clutch, but it surely isn't a permanent fix.

Just sat and read this whole thread, and thought, this is what I just went through. Turned out to be a wire to the resistor right behind the drivers headlight was corroded and had a bad connection. Found out about this from another recent thread about A/C pressures causing the fans to come on. The fans on the 400E were running a LOT on high speed which they never seemed to do before, and the temps were routinely going over 100. Check that resistor.
Here is that thread.
http://www.peachparts.com/shopforum/showthread.php?t=193757

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95 SL500 Smoke Silver, Parchment 64K
07 E350 4matic Station Wagon White 34K
02 E320 4Matic Silver/grey 80K
05 F150 Silver 44K

Sorry for the late post....

My E420 had 2 leaking radiator hoses. They were so slight that they never made any drips on the ground. My mechanic found then and fixed then, so now the coolant is holding steady.

As far as the coolant temp, it still seems high. For the first 20 minutes of driving the needle will stay just above 80, then it will go up to 90 and fluctuate between 110 to 100. Sunday in Palm Springs (over 100 degrees) the temp went past 110 to about 115, but I was in stop and go with the AC on full blast.

I still don't trust the VSC. I should have spent the $650 for the real MB part and the extra money for a real MB-Behr radiator instead of the cheaper Behr without the MB logo. My mechanic seems to think MB keeps the best Behr radiators to put their logo on.

From now on, it's all real MB parts for my car, no OEM.

Craig

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1994 E420, Pearl Black/Black. 2.82 rear diff., AMG front spoiler, painted lower half. SOLD

1972 & 1974 BMW 2002tii's.