Re-newing Thermostat

[sonic71]

Hi all,
Have recently purchased a 2.0Ltr 190e and I'm looking to replace the thermostat as I have a suspicion that it is stuck open. My question comes from the fact that I cant seem to locate the engine block drain plug - the haynes manual say located on the right hand side (all I've found so far is the sump drain plug). So if I drain the radiator only, is it OK to mix the new antifreeze with what ever is left in the engine block. The reason I ask is that the new stuff from MB is a dark green/blue colour and after checking the coolant in that expansion tank it is a reddy/orange colour.

Many thanks

Adam

 

[Bumper]

Hi all,
Have recently purchased a 2.0Ltr 190e and I'm looking to replace the thermostat as I have a suspicion that it is stuck open. My question comes from the fact that I cant seem to locate the engine block drain plug - the haynes manual say located on the right hand side (all I've found so far is the sump drain plug). So if I drain the radiator only, is it OK to mix the new antifreeze with what ever is left in the engine block. The reason I ask is that the new stuff from MB is a dark green/blue colour and after checking the coolant in that expansion tank it is a reddy/orange colour.

Many thanks

Adam

It would be OK to mix the antifreeze but the cylinder block drain plug is under the exhaust manifold just roughly where the down pipe connects to the manifold.

 

[sonic71]

Thanks Bumper I'll have another look after the Liverpool game has finished

Adam

 

[mike65]

Good man! Another solid win for us today

Mike.

 

[sonic71]

Woot yes indeedy.

Couldnt find the engine block drain plug and light was failing so I just drained the rad, changed the thermostat, refilled with 1.5 Ltrs of MB antifreeze and 2.5 Ltrs of water then ran engine to temp. Everything works OK

Adam

 

[sonic71]

AARRGG!! - Is this true:
The difference between the two colors is that orange antifreeze contains a different type of corrosion inhibitor that has a much longer service life than silicates, phosphates and borates. Orange antifreeze contains organic acids that protect engine parts from corrosion. Silicate (green) type antifreeze does not mix with orange type antifreeze. Never mix the two colors in a cooling system. The organic acids in orange types will cause precipitation of silicates in the green type and corrosion protection is greatly reduced. Orange type antifreezes are good for five years or 100,000/150,000 miles in newer vehicles (1996 and later).

The stuff I used was from the MB dealer but was very dark Green/Blue in colour and not orange - the coolant in the car was of an orange colour and because I couldnt drain the engine block there is about a 50 - 50 mix of both types now in my cooling system - is this gonna be OK or do I need to replace all the coolant ASAP. (I'm hoping that the orange stuff was from MB and the with the new stuff also from MB then it should be OK).

Adam

 

[mike65]

www.cartalk.com/content/columns/Archive/2000/August/08.

http://www.usedcarmart.co.uk/forum/showthread.php?t=1244

erm...

Mike.

 

[sonic71]

Thanks Mike,
See thats why I'm confused - hehe. I think I'll phone MB and ask them, only thing is I've only had the car a couple of months so I dont know if the orange coolant that was in it OAT coolant and I also dont know if the new green/blue coolant from MB is OAT or not To be sure I might go to a garage and have the system flushed and re-filled all in one go, it'll have to be after a get paid in a couple of weeks but that should be OK

Adam

 

[Stevie A]

You could flush the system yourself easy and get MB antifreeze from a MB van dealer a lot cheaper than from the car dealer. It's the same part number. Then the whole system would be flushed out properly. Red or orange sounds like rust to me possibly but I did once use yellow-ish Renault coolant.

 

[clive williams]

Red or orange sounds like rust to me possibly but I did once use yellow-ish Renault coolant.

Comma high performance anti-freeze is red as sold by ECP

Clive

500E
E320CDIT210

 

[Ian Brown]

Here is a picture where the drain plg is mounted.

 

[sonic71]

Cool thanks for that Ian - doesnt look that easy to get to without jacking the car up. I phoned MB (service dept) today and told them what I did - they said that it shouldnt be a problem and it should be OK

Adam