Do I have to drain coolant to replace int. coolant thermometer?
Thread Starter
Senior Member
Joined: Nov 2013
Posts: 323
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From: Los Angeles, CA. USA
2013 c250
Do I have to drain coolant to replace int. coolant thermometer?
I don't even know what this stupid part does, all I know is it makes my check engine light go on and I want it off. From a youtube video, it looks sooooo easy to replace, but the dude drained the coolant first and that looks like a PITA. Is it necessary to drain the coolant? WHY?!
MBWorld Fanatic!
Joined: Jun 2002
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From: So. Oregon Coast
C230 Sport Coup + 2006 W164 ML350 + 99 Ford Escort RIP
Drain coolant is easy. Open valve on radiator, drain to pan.
If you don't drain coolant will be coming out of the uh...
thermostat?
If you don't drain coolant will be coming out of the uh...
thermostat?
Member
Joined: May 2006
Posts: 102
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From: Vancouver, BC
2002 C240
When you replace the thermostat, you don't have to drain all the coolant, you can drain the coolant to just below the thermostat level. This way when you remove the thermostat housing, coolant won't spill everywhere.
The drain plug (red in color) is on the bottom of the radiator. Remove the front engine panel under the car to access. Use a screwdriver and turn the plug counter-clockwise to loosen. You do not have to remove it completely. If you use a clean drain pan, you could most likely re-use the coolant. Good Luck.
The drain plug (red in color) is on the bottom of the radiator. Remove the front engine panel under the car to access. Use a screwdriver and turn the plug counter-clockwise to loosen. You do not have to remove it completely. If you use a clean drain pan, you could most likely re-use the coolant. Good Luck.
Out Of Control!!
Joined: Nov 2001
Posts: 10,067
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From: Westwood, NJ
2004 Civic Si. FWD for the Win!
Technically, no, you don't HAVE to pre-drain it. It will simply come out when you take out the thermostat, create a huge mess, possibly damage various parts in the engine bay, and be an environmental hazard as it seeps into the ground or runs off. But if you're willing to risk it, it's one less step.
Super Member
Joined: May 2009
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From: Toronto, Ontario, Canada, eh!
2003 C230 Sports Coupe, Paprika Metallic Red, Auto, Pano, Leather
Of course you do NOT have to drain coolant to replace thermostat!
Find a nice vertical ramp at your local skateboard or bmx park,... Drive car up ramp so nose point straight up in the air,.... Thermostat will now be highest point of coolant system,... Change thermostat and you won't loose one drop of coolant. Of course some punk-kid can come along and kick your front bumper to tip your car over,.... Minor details!
Find a nice vertical ramp at your local skateboard or bmx park,... Drive car up ramp so nose point straight up in the air,.... Thermostat will now be highest point of coolant system,... Change thermostat and you won't loose one drop of coolant. Of course some punk-kid can come along and kick your front bumper to tip your car over,.... Minor details!
Thread Starter
Senior Member
Joined: Nov 2013
Posts: 323
Likes: 4
From: Los Angeles, CA. USA
2013 c250
Talked to an indy mechanic who said you actually can change it w/o draining the coolant if you're fast enough and by using your finger as a stopper until the new piece is installed. What I'm not sure about is if there's a NEW O ring that I should have or just the piece below? A video shows there is an old O ring with it and not to reuse it. 
