W211 648 CDI Water Pump - PeachParts Mercedes-Benz Forum

GregMN · #1 05-16-2015, 04:36 PM

Our new-to-us CDI has just under 202k on it.
The water pump failed.

I looked at the 2" space between the top front of the engine and the radiator shroud and electric fan. I figured I would have to remove the top support and the radiator to do the job.

I checked the procedure on WIS. No mention of radiator removal. So I start scoping out the job figuring I might as well get a start tonight, then finish it tomorrow.
The procedure calls for:
removal of the engine covers
removal of the front bottom panel
removal of air ducts to and from the air cleaner box
removal of the upper coolant hose
removal of the 2 hoses from the water pump
removal of the 2 drive belt idler pulleys, one on the pump to access a bolt behind it
removal of a bracket

I did the following:
removed the engine covers
removed the 2 upper coolant hoses from the thermostat housing
removed the bracket
slid the drive belt off the D/S idler pulley
unplugged the electrical connectors from the HP pump ( fuel temp sensor, fuel quantity valve ) so I did not catch on the wires and possibly break them
removed the 2 coolant hoses from the water pump
removed the 2 drive belt idler pulleys ( T50 ), after prying the plastic cover off the pulley for access the the bolt head
I used a mirror to find all of the water pump bolts. 2 sizes E-torx 10 & 12 ( External Torx sockets )
I used this ratchet to reach all the bolts: T-Bar with 3/8" Flexible Ratchet
I was surprised that I could get the all important opposable thumb on the head of every bolt.
I did not remove the bottom panel and the only reason I could see for doing it would be to let anything you dropped find it's way to the floor for easy retrieval. You might need to do it to properly drain the radiator.
With all the bolts removed and the water pump loose, I removed the power steering pump pulley and loosed the bolts on the upper support so I could move the radiator forward just enough to pull the pump out.
Took me about an hour and a half with 3 trips back to the computer to view the diagram to find all the fasteners.
Only one bolt required the flying superman position across the P/S fender to hold the ratchet on the bolt head.

So, it wasn't scary at all. The articulated ratchet was very helpful. The reputation of the 648 as being an easy engine to work on was true in this case.
When the new pump arrives and I get it installed I will report back, but it should be straight forward.

Skid Row Joe · #2 05-16-2015, 05:36 PM

What is "WIS" website?

GregMN · #3 05-16-2015, 06:14 PM

Quote:

Originally Posted by Skid Row Joe

What is "WIS" website?

Smart Wis Asra EPC Ewa 2013 Service Shop Repair Manual Set Combo Pack | eBay

GregMN · #4 05-21-2015, 02:38 PM

Water pump installed in about the same amount of time it took to remove it.. It took longer to connect the hoses and get the drive belt installed then it did to bolt the water pump on.

Randy · #5 03-10-2018, 06:34 PM

I tackled the water pump today with the reinforcements provided by Greg. I agree it is doable, but it sure isn't a '52 Chevrolet... One thing I did differently: I removed the air cleaner box and the air elbow from the turbo and removed the pump that way. It also made it easier (to me at least) to access the bolts to get it back together.
I bought the tensioner and one idler; alas! there are two identical idlers and I need to order another. All were still together but the bearings sound dry and a little rough. I don't doubt they are original. I got as new belt and
I will also change coolant hoses while I am in there.
Thanks again!

sixto · #6 01-12-2019, 12:04 PM

The pulley doesn’t have to come off the water pump.

Sixto
98 E320s sedan and wagon
02 C320 wagon