S54 water pump rusty inside

[r3_galek]

Took off my water pump today, and the thermostat was stuck to the housing (managed to get it out after a while), there’s a bit of gunk in the thermostat housing and some corrosion. And the water pump housing on the engine is rusty as are some of the metal pipes slightly, did a bit of scrubbing and seems a lot of it is coming off. I assume someone used tap water or mixed in some wrong coolant into there. Any advice as to what to do? Sand down the engine surface a bit with wet sandpaper or a Brillo pad or something? I can post a picture tomorrow as forgot to take one today. Thanks in advance

Would it also be beneficial to change the thermostat housing or would cleaning it up be enough? As it’s rather hard to push the thermostat into place, but I think it should fully go in

[Slideways]

Might have to flush out the system with distilled water once or twice. A scotch bright pad should be able to clean up the corrosion where the thermostat sits in the thermostat housing.

[beemer_guy]

Took off my water pump today, and the thermostat was stuck to the housing (managed to get it out after a while), there’s a bit of gunk in the thermostat housing and some corrosion. And the water pump housing on the engine is rusty as are some of the metal pipes slightly, did a bit of scrubbing and seems a lot of it is coming off. I assume someone used tap water or mixed in some wrong coolant into there. Any advice as to what to do? Sand down the engine surface a bit with wet sandpaper or a Brillo pad or something? I can post a picture tomorrow as forgot to take one today. Thanks in advance

Would it also be beneficial to change the thermostat housing or would cleaning it up be enough? As it’s rather hard to push the thermostat into place, but I think it should fully go in

When you say rust and corrosion, is it like this? And I assume you mean on the outside? I had some crust built up and cleaned mine up with a nylon brush and simple green. For the flat surfaces I carefully used a razor blade and had no issues. With the pipes going into the water pump, I cleaned them up with some scrubbing with the blue shop towels and a nylon tool pick, although I didn't put a lot of effort as it was only on the outside surface. I've drained everything through the engine block drain plug and other hoses, and plan on doing a flush with maybe a couple rounds of DI water and then the regular 50/50 mix after.


I highly recommend getting the O-rings from the water pipes to the water pump housing replaced, you can see the stark difference between the two.

Apologies for the orientation of the pictures, it shows as the right orientation normally on my computer but for some reason all but the 1st are rotated when I uploaded them and I can't seem to change them.

Edit: I also have the Liquimoly radiator cleaner, so I will likely use that as well.

[Keith_MN]

Mine was very corroded, not sure how it got to where it was but here's what I did:

Get it hot, flush system.
Removed all cooling system parts. Snaked a pipe cleaner brush in the block as much as I could.
Flush system as much as possible when it was disassembled.
Replaced radiator, expansion tank, water pump, thermostat, all soft hoses and the hard pipe on the exhaust side.
Replaced engine block drain bolt with fitting/hose for easier servicing
Flush again.
Fill up with CRC Thermocure & water, follow the directions.
Flush again.
Fill with coolant/water.

Has been good since.