Pelican Parts
Mercedes-Benz Parts Catalog Accessories Catalog Mercedes-Benz How To Articles Mercedes-Benz Tech Forums
Call Pelican Parts at 888-280-7799
View Recent Cars  |Shopping Cart Cart | Project List | Order Status | Help
 >  >
Coolant Temperature Sensor Replacement
 
Bookmark and Share

Pelican Technical Article:

Coolant Temperature Sensor Replacement

Steve Vernon

Time:

2 hours2 hrs

Tab:

$1 to $20

Talent:

*

Tools:

T30 Torx

Applicable Models:

Mercedes-Benz C350 (2008-14)
Mercedes-Benz GLK350 (2010-14)

Parts Required:

Coolant temperature sensor

Hot Tip:

Use a mirror to see the sensor

Performance Gain:

Proper temperature readings

Complementary Modification:

Flush cooling system

The coolant temperature sensor is located on the rear of the left cylinder head. Replacement is not that difficult but you will be working with the coolant so take proper precautions; first make sure the coolant is below 40 degrees Celsius. Wear gloves and be prepared to catch the coolant and dispose of it in accordance with the regulations in your area. Also even though not a lot of coolant will escape make sure to refill and bleed the system when you are finished.

You will need to remove the engine covers (red and yellow arrows) and air intake ducts (green arrows) to perform this work.
Figure 1

You will need to remove the engine covers (red and yellow arrows) and air intake ducts (green arrows) to perform this work. Please see our article on engine cover removal for additional assistance.

Once the system has cooled to below 40 C slowly open the coolant reservoir cap to release the pressure in the system.
Figure 2

Once the system has cooled to below 40 C slowly open the coolant reservoir cap to release the pressure in the system.

Reach down behind the left cylinder head and disconnect the wiring for the crankshaft-positioning sensor (red arrow).
Figure 3

Reach down behind the left cylinder head and disconnect the wiring for the crankshaft-positioning sensor (red arrow).

Next reach down behind and disconnect the wiring for the coolant temperature sensor (red arrow).
Figure 4

Next reach down behind and disconnect the wiring for the coolant temperature sensor (red arrow).

Use a T30 Torx on a 1/4-inch drive socket and reach down and remove the single Torx screw (red arrow) holding the sensor plate and sensor in place.
Figure 5

Use a T30 Torx on a 1/4-inch drive socket and reach down and remove the single Torx screw (red arrow) holding the sensor plate and sensor in place.

You can now reach down and pull the sensor straight out.
Figure 6

You can now reach down and pull the sensor straight out. Coolant will flow out so be prepared to catch it. If you are quick and prepared to install the new sensor right away there will be minimum coolant lose.

If you are reinstalling the original sensor always replace the O-ring (red arrow).
Figure 7

If you are reinstalling the original sensor always replace the O-ring (red arrow). Installation is the reverse of removal. With the sensor installed and tightened down do not forget to top up and bleed the coolant system.


Bookmark and Share
Comments and Suggestions:
ChuckSnow Comments: AKI...verify the old oring is removed. you may have double stacked orings.
December 19, 2016
  Followup from the Pelican Staff: Thanks for the additional info. We appreciate it.
- Nick at Pelican Parts
 
Aki Comments: I installed the new sensor with new o-ring. I pushed it in as much as i could. I tightened down the torx bolt. I am still able to wiggle the sensor around though. The Copper collar around the sensor is not completely inside the cylinder head.

Is this normal?
December 8, 2016
  Followup from the Pelican Staff: No, possible the sensor is bottomed out. Can you confirm you have the right part number? - Nick at Pelican Parts  
Lee Comments: Is the procedures to replace this sensor on a 2011 C300 the same as this procedure? I don't find a sensor where the picture indicates on my C300
June 22, 2016
  Followup from the Pelican Staff: Applicable Models:


Mercedes-Benz C350 (2008-14)
Mercedes-Benz GLK350 (2010-14)


I would grab a repair manual. It will have the procedure, special tools and torque specs.

Give our parts specialists a call at 1-888-280-7799. - Nick at Pelican Parts
 

QUICK LINKS
About Us
Careers
Pelican Parts, Inc.
1600 240th Street
Harbor City, CA 90710
Order Online or Call:
888-280-7799
CONNECT WITH US
NEWSLETTER
Sign Up for Pelican Pit Stop News & Special Offers
Page last updated: Sat 3/25/2017 02:58:35 AM