OK, i've changed the thermostats on the 300E and 190E a couple of times but this E430 seems to be a totally different intimidating beast ! especially with everything hidden under the engine plastic cover and all !
nevertheless, it's time for a thermostat replacement (i think) as the temps were in the 20's last nite and the engine temp wouldnt go above 80 mark. is that normal ? the needle never goes above 80... from what i recall the thermostats are meant to operate around 87deg.
so i figured i'll change the thermostat. if someone would be kind enough to post a pic or two of where to start and where the location is, more over do i need to do something special to get the engine cover off ? first time with the w210
i think the w124 was a whole lot easier to work on !

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Whether you think you can or cannot, Either way you're right!. by Henry Ford.

do you understand the function of the termostat? its ment to open and allow water to to run pass the valve when the temperature reaches over the set (example your termo is made for 87 degrees) then it opens full but unless the temp reaches a high it will remain close and the water flowing thru the valve will be restricted. old saying when its not broken don't ifx it or even touch it.

yes i know the function of the thermostat. when a thermostat goes bad it doesnt let the temprature rise enough and leaves the engine running cold.
a bad thermostat is meant to leave open by default.
was ur purpose to just increase the number of posts you have as you really didnt answer the question. next time refrain from making comments that arent needed.

__________________
Whether you think you can or cannot, Either way you're right!. by Henry Ford.

could someone post what their normal temp range is during ice cold winter season on the w210's. thnx

__________________
Whether you think you can or cannot, Either way you're right!. by Henry Ford.

Mine has barely reached 80C these days. It's slow to warm up in comparison ot my M104 engine, which is surprising since the M113's all-aluminum block should conduct heat faster.


Maronites today

Benz 300, with that attitude no one should give you the time, go figure it out yourself!

your thermostat sounds normal. wait til spring or do a 200 mile trip, methinks the gauge will hit 80

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Current cars:
2001 MB E55 AMG
2003 Honda S2000
2000 Honda CRV

Gone but not forgotten:
2004 BMW 325i 5sp sport
1999 BMW 540i sport
1997 MB E420
1995 BMW M3 coupe

dude what's w/ the hostility? loosen the panties, or is it pms time?? lol

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Current cars:
2001 MB E55 AMG
2003 Honda S2000
2000 Honda CRV

Gone but not forgotten:
2004 BMW 325i 5sp sport
1999 BMW 540i sport
1997 MB E420
1995 BMW M3 coupe

Under normal driving conditions (not stop and go in the summer), the coolant temp of a car that has been driven for 10 minutes should be around 87 degrees Celsius. This should be independent of the season. However, with AC on in the summer, the temp could go beyond 87 deg.

If it does not get to 80, that means the thermostat cannot close completely so some coolant get through the thermostat to the radiator so the engine never reaches operating temperature. This is largely caused by the fatigue of the spring in the thermostat. In my experience (4 cars), the Mercedes thermostat seem to have a lifetime of about 60k miles. Beyond that, the main symptom of failure is that the temp won't reach 80 degree (stuck partially open). Cool running engine is not good because it causes more wear to the engine and reduces fuel efficiency.

I just started another thread about my 2003 E320 Wagon (also W210). I bought it yesterday and after over 1 hour of driving on the highway the temp is still one needle width below 80. The thermostat needs replacing and I have just ordered the part today.

Although these are different engines V6 vs V8, I found the location of the thermostat is very close. If you follow the upper radiator hose toward the engine, you will find the thermostat housing. The thermostat seems to sit in a vertical position. (The 103 and 104 thermostats were horizontal and on top of the engine so they were very easy to replace.)

Here are some pictures from a 2002 E55. Again, the position seems to be close to where the one in a M112 is.

http://www.mbworld.org/forums/showthread.php?t=161123&highlight=thermostat

Next time, pay your mechanic to diagnose your car, instead of being snooty to someone who is giving you free advice.

I could help you, but I wouldn't give you the time of day.

Read your owners manual.

for those who think i overreacted, that's because instead of answering the question one of the member was telling me that I don't understand the concept of a thermostat and have it figured wrong.
If I should just say "thanks" to that and agree I have no idea of what a thermostat is, then sure.
let me just do that. based upon that i probably shouldnt even have asked this question...
thanks to those who actually did reply technically to a technical question. much appreciated !

__________________
Whether you think you can or cannot, Either way you're right!. by Henry Ford.

You read too much into his reply, and if you want professional answers to a technical question, your dealer will be happy to answer it for a price.

The thermostat shouldn't start letting coolant through until the engine hits 87C. If the top hose gets hot much before that, it would indicate a faulty thermostat. You have to start checking when the engine is cold, of course.
I don't think replacement is difficult, just you need to replace the housing and thermostat as a unit.