Its been freaking cold here in Edmonton, Canada the last week or so, this morning was -34C. As per my other post, I also think that I have a thermostat issue. What better excuse is there to take the new-to-me car apart? I had a webasto thermo top c sitting in my garage for over 2 years now - originally meant for my Smart car that I never drive in the winter anyways.

I wasn't able to find any good instructions on how to install a coolant heater on our GLK250 BT anywhere. Webasto did have some instructions on the gas models and a generic install guide (pm me if you want the PDFs, though you can find them easily via Google). This is just a documentation of my journey, not sure if everything will go well and work right, but what the hell...got'ta try.

!st step was to jack up the front RHS and remove the wheel. The 2nd was to remove the fender liner - back side comes off first, then the front.

Area where the webasto will go

Because of the instructions were for a different coolant heater, the dimensions were different and I can't follow everything exactly, I decided to remove the thermo top C's circulating pump and opted to use the GLK's factory circulating pump.

Pump on

Pump off

In the process of mock fitting the heater, I noticed one of the coolant line was tucked below one of the support bracket for the bumper. It looked odd as it kind'a pulled the coolant reservoir on its side as the hose was a bit short. I decided to route the hose above the bracket giving a bit more room.



Made some aluminum brackets to bolt on to the crash bar just to test fit - will make them out of something stronger when I have everything together for the final fit.

I made 2 of these after I measured the height I wanted it installed

Here's the mock fit with a 3/4" (19mm) hose

Mock fitted

This was as far as I got. I removed the heater and reinstalled the fender liners - will need the car for work tomorrow. I still need to find harness connectors for the X1 (control wiring) and X2 (power/ground), Relay and fuses, and all the fuel side components. As mentioned before, I will use the OEM circulating pump - splice in the control relay or wiring with a diode or something. Will post more as I go.

Please chime in if you've done this before or have ideas on how to progress.

Izzy

 

Hello Izzy,

I have an GLK 320cdi and would like to install the webasto heater also, found a few of them secondhand and will also do the works myself.
Found some install manuals online, also for the 220 cdi engine, attaching it here if it could be of any use for you.
Keep us posted of how its going for you.

all the best
Martin

 

I recently purchased a Webasto Thermo Top Evo for my newly acquired 2016 Mercedes E250 Bluetec, living in Manitoba we can get some harsh weather of -40C, was wondering how your journey went and if you had any luck installing your unit?

 

Wow its been a few months since I've done anything to the GLK!

So the webasto is in. I ended up making a bracket to permanently mount the heater, semi wired the harness and plumbed the coolant lines. I have not tap into the fuel tank yet nor have I finish wiring my controller inside the cab. Will upload more info when I get the motivation to finish.

Martin-GLK - I have something similar that I used for installation, thanks though.

LeonF - Finishing this heater is a must for the winter. Whenever it gets to -30C, my GLK will not get up to full temp even on the highway.

 

Always nice to upload some pics I guess.


Homemade bracket for the heater


Hole already there from factory for the exhaust in the plastic liner


Coolant route

 

Yes be sure to change the thermostat. My 13 is not working right . And block off all air entrance

 

We’ve had this discussion before remember? I’ve told you last year that thermostat was already replaced, grille blocked and vacuum is checked. It’s just the reality of living in below -20C weather. We had that whole discussion where you disagreed with us guys with diesel claiming lesser temp than gassers? Anyways…I do appreciate the willingness to help.

But hopefully finishing the heater will resolve the issues with the short drive or extreme low temp situations.

 

Be sure to replace the thermostat , mine is failing at 70000 m and block off all air entrances . I screw on a black foam board
know it has airflow and cooking for the Saudi’s 130f desert . Block off airflow

 

So the Thermo top C with Smartemp fx has been finished and running for about 3 weeks now. I’m fairly happy with the result. The heater can be run simultaneously with the engine - significantly helped with maintaining coolant temps in the city. Definitely a must have when the weather was -37C a few weeks ago! I usually run it 30-40mins before I start the engine when I don’t have the option to plug in the block heater.

I ended up taping the fuel tank on the passenger side and ran the fuel line along the right side of the car. There’s actually OEM clips along the way that you can use! Had to modified the access cover to get a little more room for the stand pipe. I also ran a relay setup to use the OEM coolant circulating pump rather than the webasto’s circulating pump. It was also quite easy to run wires through the firewall via the fuse box on the driver’s side.

Sorry I did not take any more pics as I was running on a tight schedule when finishing the install. But, if anybody here has questions, I will be happy to help/answer.