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W210 thermostat changing

6K views 42 replies 14 participants last post by  Hsniper 
#1 ·
Peace be upon you, may God protect everyone in the these days that the world passes through. Our topic here is the type of the thermostat with the W210 , one for the six cylinders M112 opens at 87c and one for the E200 open on 71c ..can we here change the inner body from housing of thermostat which open on 71 c and put in the thermostat housing of M112 instead of 87 c.. waiting your opinions ...
 

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#6 ·
Let's don't start another thread about German moving to Kuwait. As long as temperature does not go above 120C you are fine.

 
#9 ·
Not possible, since thermostat is cast into the housing itself.

Also, suppose you change the thermostat. Then your gas mileage will suffer because engine is not being at optimum temperature, so ECU will waste more gas trying to heat up the engine.

You could change radiator if it is original, a new radiator can make a drastic difference.
 
#12 ·
We also get many 40c days here in Australia and many times I have seen outside temp at 40c+ with engine temp at a normal 85 to 90c. Your engine temp is also displaying at normal number. Car manufacturers, including M-B, design their vehicles to operate all over the world. My suggestion, leave well enough alone; your vehicle is operating to spec..
 
#13 ·
If the thermostats are the same dimension, you can swap them out. You can remove it by twisting it off the mount. It is held in place by the spring underneath.

However, I don't think it will make the car run cooler in a hot location. It will just open sooner at a lower temperature.
 
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#14 ·
The volume flow to cool isnt going to increase. To lower the temps, you need more volume of coolant to flow thru. As 26e stated, you're only opening the flow sooner. Deplore said change the radiator (larger) or perhaps retrofit a cooler to it (similar to a transmission cooler - to increase volume flow)
 
#15 ·
How about a manual switch to run the radiator fan at full speed. Mind that it’s a high amperage circuit with a 50 amp fuse. You’ll need a way to isolate the original fan controller when you run the fan manually.

Maybe you can ditch the electric fan for a tropical rated mechanical clutch fan. US ‘98 E320s, basically the same V6 block, and all US V8 210 models have mechanical clutch fans, and auxiliary electric fans ahead of the AC condenser.

Sixto
98 E320 wagon 197K miles
 
#16 ·
1. As mentioned, it’s the airflow and water flow that determine max temperature.
2. You probably see a lot of W210 taxis driving around, which is good evidence that the slightly higher operating temps were not detrimental to engine life. I would do slightly more frequent oil changes, however.
3. Appreciate your blessings, but expect no divine interventions. Ponder this memento mori found in Pompeii.
2625780
 
#17 · (Edited)
Main factor in cooling the engine is heat exchange ratio so the radiator plays main role.
When putting lower setting thermostat will give you slight delay in engine overheating, like for example driving up 1 mile hill, it will not help much when you hit 5 mile long hill.
So having 20 yo radiator, you can expect it to generate some build up, especially when coolant was neglected.
You can use citric acid to try to restore the radiator efficiency, but from the past (before I start driving MB) I remember that those cleaners don't do much and I had to buy new radiator for Volvo just to regain cooling efficiency. (the expense over 20 years ago made me religious about using MB coolants)
I drive frequently in 120F/50C weather and my engines never go past 90C, even on Ford but I drive diesels.
 
#20 ·
Hi guys, I put an 87 deg thermostat as opposed to the 90 or 91 as recommended and that was in there. The cooling fan does not seem to run as often which I believe does not allow my ac to get ice cold in bumper to bumper traffic. This was a decision I made over a year ago when freshened up the cooling system. The vehicle is a 99 e320 wagon located in Florida USA. When I do address the cooling system in the future, or need to drain coolant for any other work, I will likely return to the factory spec thermostat.
This is just something i noticed and though was worth mentioning.
 
#21 ·
Hi guys, I put an 87 deg thermostat as opposed to the 90 or 91 as recommended and that was in there. The cooling fan does not seem to run as often which I believe does not allow my ac to get ice cold in bumper to bumper traffic. This was a decision I made over a year ago when freshened up the cooling system. The vehicle is a 99 e320 wagon located in Florida USA. When I do address the cooling system in the future, or need to drain coolant for any other work, I will likely return to the factory spec thermostat.
This is just something i noticed and though was worth mentioning.
Thanks for chiming in Meats.
Always good to hear first-hand, what a change like this can result in.
 
#26 ·
Great,
I went through the AC system a while back and charged it. I know it's a tricky system with the read outs on the climate control.

Did an AC compressor, hose orings, and both cabin filters about 8 months ago. Settled for a "rebuilt" compressor from a company out of Miami. I used them for a compressor in my truck about 3 years ago and am still ice cold in that one. Just assumed these systems dont get ice cold in their older age as my 98 sedan's ac works the same way. Cold on the highway, cool in the city, and removes most of the humidity in heavy traffic.

Bought an evaporator coil, and will switch that out if I ever end up taking out the dash.
 
#31 ·
if you go to messing with any part of an engine, there are most often many changes which will come up as a result of it. Some, you will find you dont want. In this case, the engine was made to operate best with the therm temp it came with. most times running it hotter or colder will take more gas,,,will make it not perform as strongly as it should, and wont wear as intended. Ive changed several in the 60s and 70s and sometimes hoped i would have great results with no thermostat at all. Never did it work to improve what the original worked at. Changing may make only small results, but then again, ive ruined engines by running too hot,,letting oil get thin and costing me a crank and cam in the process,,,,suit yourself,,,let us know what your changes and testing proved,,,,regards
 
#32 ·
A lower rated thermostat will not cause the engine run cooler. It will just allow the coolant to circulate in the radiator sooner (longer warm-up time). When the engine reaches its full operating temperature, the amount of heat to be transferred is the same. You either need more airflow through the radiator, or a radiator with more heat transfer surface (bigger), or both.
 
#33 ·
That was my understanding as well. I had a Land Rover Discovery that was having issues running hot. I put a t stat with a lower temp and the overheating halted. The issue was one winter when I went north, I didn't enough heat. Luckily, the heated seats worked (suprising for a British car).
 
#35 ·
I see the temp needle is too high, so you need to check all the components of your cooling system. I would start with a drain and refill with just water and cleaner, thermostat removed. drive to work and back and flush again until clear water comes out, then fill with regular high mileage antifreeze. If that doesn't do it then drill 4 1/8 inch holes around the perimeter of the thermostat. If it still stays hot then you need to replace radiator with a bigger unit or to make a bypass from your water outlet to the back of the engine. You will need to experiment, unless one of your taxi buddies has already had the same problem and fixed it.
 
#37 ·
On our hot summer days in stop and go driving I have seen my temperature needle go almost to the red. As long as it isn’t in the red you sre fine

Has anyone mentioned the fan clutch? That’s one thing to check but I think being in Kuwait and expecting the temperature to stay at 85° is wishful thinking.
 
#38 ·
And again, I frequent 120F and my diesels don't go to 90C even in heavy city traffic.
Once again, lower temp thermostat is band aid trying to stop hole in 60 psi hose. It will help only for short burst, but then it will keep engine at lower temperature on cold days.
You have to restore your cooling capacity to solve the issue.
 
#39 · (Edited)
still asking and looking for solution until i find it finally ...some benz guys here in dubai and a german mechanic told me just to drill 3 or 4 holes size 6 in the thermostat filling ...so what great results the temp is now 85 in city not more and 80 highways ...thanks to everyone help and try to help me ..
 
#40 ·
Yes still asking and looking for solution and i think i find it finally ...some benz guys here in dubai and a german mechanic told me just to drill 3 or 4 holes size 6 in the thermostat filling ...so what great results the temp is now 85 in city not more and 80 highways ...thanks to everyone help and try to help me ..
Sure. Hook up with Danial you can go bowling together.
 
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