i have a w124 e320.... id like to attempt to replace my therm... i have no clue where the therm is... so my first questions is... "where is it" ive read severaly threads about the therm housing... and that it should probably be replaced also... but again... i need to start at step one...

does anyone have any pictures.. or links i could use in order to replace this... any help would be greatly appreciated.

thanks-
charles

also, is the therm an MB only part or can i go to any auto shop to purchase one?

again.. any help would be greatly appreciated!!

-Thanks

Should probably try doing a search for "thermostat."

Pretty simple job, it's the small bell housing attached to the upper radiator hose at the front of the engine. You'll want to remove the coolant expansion tank cap, drain the radiator (at least partially), and unbolt the three bolts securing the housing. Dig out the o-ring with a small pick, remove the thermostat, and install the new one+new o-ring. The small ball valve on the thermostat goes at the highest point (usually on the block side of the housing).

The real question is - why do think you need to replace the thermostat?

thanks-

the engine has been running very warm at ideal... warmer than it has ever been... getting close to 120.... but when im driving it goes back down to 90ish or so.... the car has a new radiator (dealer installed)... and no leaks around the water pump..... so thats my next guess....

thanks again...
-carino

more like a fan issue than thermostat. are your fans working properly? i suggest a search for fan clutch diagnosis, and the electric fan diagnosis. there have been a lot of discussions about it recently on this forum.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

the aux fans infront of the radiator turn on properly... turn on around 100 or so...
-charles

I know this sounds crazy, but are you sure the fans are blowing in the right direction? I read a post here last month where the guy was having major cooling problems at idle and couldn't figure out what was causing it as the rad was good, the water pump and thermostat were good, and the aux fans came on right when they were supposed to. It turns out that the fans were spinning in the wrong direction so instead of pulling air from outside the car through the radiator to cool it, they were pulling hot air from the engine compartment through the radiator which wasn't helping the temperature.

If I remember right, this happened because the aux fans had been plugged in backwards when they were removed at some point. Do a search, I'm sure you'll find the thread. If you want to check yourself, take a piece of paper and hold it up in front of your grille when the fans are on. The paper should be pulled towards the grille. If the paper is pushed away, then your fans are turning in the wrong direction.

Its a cheap and easy thing to check, so as crazy as it sounds, give it a look.

Jonathan

I would agree it sounds like a fan problem. With the engine running, unplug the large plug on top of the thermostat / upper hose housing, and see if your two fans come on full speed. There are at least two fan speed settings, when on full they roar, you will know. Then plug back in. If temp gets real hot, you can run the heater to bring engine temp down quickly. Good luck. Are you using MB pink / orange coolant? (Probably if dealer changed radiator)

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2002 Mercedes-Benz E320 4Matic
1995 Mercedes-Benz E320 Wagon
2005 Land Rover LR3 V8 SE
1999 Audi A8 4.2L quattro

The engine (at least the M103 sixes) will get pretty warm at idle in the summertime. 100-105 is pretty normal. Mine will get up to 110 with the A/C on and it's 100+ outside. As long as it doesn't hit the redline...

Is your fan clutch working okay? Couple of ways to check - does it engage when you first start the car and drive off? Is it engaged after sitting idle for a couple of minutes (and when the coolant temp is 105+)? You should get a pretty noticeable roaring sound from the engine fan when the clutch engages.

ill try this later on.... thanks for the advise.... i hope my dealer didnt install the fan wrong... or im going to be PISSED!!!!

thanks- im not positive as to which coolant the dealer used... im assuming its the mb stuff.....

anthony- thanks for the suggestions as well- this is going to sound really stupid... but what exactly is the "fan clutch"....

when i turn on the car in the morning.. or after it has been sitting awhile... the aux fans are not on.... once the tempurature on my gauges gets to 100 or so the fans turn on.... they pretty much stay on when ever my therm gauges reads anything higher than 100-110ish... the therm has never redlined but has came very damn near close to it.... it only gets hot after i get off the highway or if im at a stop light..... the temp cools down as it is supposed to do when i am driving....

owe... and this is all in Kansas city... 90+ degree weather and the a/c on full blast....

i know something is wrong... owned the car since new and it has never got this hot....

below is a picture of the temp reading at a stop light....

thanks again for your guys advise... ill check the fans... and once i figure out what the fan clutch is... ill check that out as well

-charles

Attached Images

temp gauge.bmp (24.2 KB, 81 views)

But I wouldn't discount the thermostat, either. I've had a couple stop working over the past decade in my BMWs. I suspect they get old, and I've been told that you can "cook" them--say if you nearly overheat the car for other reasons (like losing a fanbelt). I try to remember to replace them every coolant change.

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TomO
94 E320 Wagon, 170k, totalled in 2006
2002 BMW 525i Wagon, 75k
1991 BMW 318is (two of 'em)

hey everyone... id like to thank you all... especially jlomon... it turns out that when i had my radiator changed.... the dealer did install my aux fans wrong... it does blow away from the engine and not towards!!!! the car is in the dealer today... and before i dropped the car off i stopped off at a gas station to fill up (prem crzay here in kc $3.19).. i checked the fans.....

my next question... what problems could this possibly have lead too??

-again.. thank you all...

charles carino

Hi Charles,

I'm happy I could help. This forum has been really good to me over the years, so I'm glad to be able to return some of that.

As far as long term damage/consequences are concerned, if your car didn't actually overheat, I don't think you'll have any problems. Of course, I'm not a tech, so you may want to solicit opinions from more experience people than me.

Jonathan