|
|
|
|
|
#1
03-02-2011, 11:49 AM
|
|||
|
|||
Thermostat not opening??
On my 1980 300SD i just replaced the thermo and coolant. Put the car on ramps and ran the engine until the temp got to 90Degrees plus. Put the cap back on the overflow but the thermo is still not opening. I checked that it was a 80 degree thermo before it opens. The side of the housing closest to the block registers 80 plus but the bottom part of the housing is only going to 45 degrees. These temps are taken using a thermo gun. Any suggestions or do I puu the thermo out and see what is keeping it to open. I am pretty sure I installed the thermo correctly.
|
|
#2
03-02-2011, 12:55 PM
|
||||
|
||||
|
You have to get it warm enough to open the stat so that you can get the air bubble out. Only after doing that will you get a true assessment of how it is functioning.
__________________
[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.
|
|
#4
03-02-2011, 02:18 PM
|
||||
|
||||
|
The thermostat needs to be oriented in the proper direction and I have read there is some sort of mark on it that also needs to be lined up.
Last year I did not follow the advice I am giving. I bought a new Thermostat (not for a Mercedes) and put it on. Only to find out that it opend way too late. In the past I used to test the Thermostats before I installed them because it is a lot of work to change them but this time I got lazy and did not. I ended up causing myself a lot of work and ended up testing it anyway to be sure it was no good. You get a pot and state heating the Water on the stove and add a teaspoon of Salt to the water so it will not bubble much. Get something like an old wire Coat Hanger and Wire and suspend the Thermostat so that it does not touch the bottom of the Pot; you only want the water to heat it. Stick a Thermometer into the Water (also not touching the Pot) and as the heat rises see what temp the Thermostat begins to open at and you can also let it cool down and see what temp it cloes at. I used to use aGlass or Metal Candy or Meat Thermometor to do the test but now have a Digital Meat Thermometer to do that. In my case the Thermostat was opening 10 degrees late and it was a stock temp 195 degree thermostat (again not for Mercedes). This also gave me some supportive info to tell the Parts Guy.
__________________
84 300D, 82 Volvo 244Gl Diesel
|
|
#5
03-02-2011, 04:32 PM
|
|||
|
|||
|
I just came back from a 8 mile run. The housing that holds the thermo was at 203/119 measured with an infra red gun. The lower hose from the thermostat housing was reading 100/39 again with my gun. The hose from the back of the engine block to the aux pump tube was 170/78. The bottom hose to the aux. pump was 165/75. My gauge on the dash says the thermo opened at 80 to 82 and then went steadly up to 95/100 on the dash. As I am used to 80 degree readings on my other 2 mercedes I am trying to figure what is wrong.
As we are in SO FL the temp is important to my mind as I am always worrying about overheating. I am wondering if the fact that the aux.water pump seems not to be working if that is what is causing the issue.
|
 |
| Bookmarks |
|
|
Linear Mode
