Metal object inside water pump

[mikhogl]

Hello!

I have some strange problems with my ec 300 2013. I had it since new and after 32h i found a metal object inside the water pump. It must have been there since it left the production line. I went to my local dealer and they replaced the plastic impeller since it was worn from the object. Another strange thing is that the coolant is black, still the coolant is not smelling like oil or exhaust fumes? I have tried to get some answers from my local deler but they cant tell me anything about the black coolant and they claim that there is no additional wear or damage. What do you guys think about the following:

1. why is the coolant black?

2. How much damage and additional wear is done to engine because of the metal object in the pump?

3. anybody else with similar problems?

Best Regards

[Neil E.]

The black might be from oxidation of the aluminum engine castings. Wear from your impeller usually results in some shiny spots on the housing and slight particles of aluminum with hardly any darkening of the coolant. Maybe the quality of the coolant was poor and it was attacking the engine alloy.

Do you have a coolant tester? We used litmus paper in grade school science class to test for acidity.

That is quite the mystery part. Is it aluminum? If so the impeller could have rubbed it enough to create the black mess.

[(F5)]

Ha looks like a squish test bit of solder that got dropped in the jacket when head taken off. But it would be super soft and not survive the impellor of doom.

[twowheels]

OP didn't mention having the head off, but I agree it looks like solder. Ruling that out means that somewhere along the production line somebody dropped something in.

The coolant is too black to be simply oxidation at that few hours, no? More likely the three part pump seal is gone. If it was a head inner o-ring the bike should have been smoking and the coolant would have largely burped out.

I'd drain the trans fluid and see what you come up with there.

[Neil E.]

One interesting thing is that the black fluid shows no separation in the bottle. If it was oil contamination, I'd expect to see some scum at the top of the liquid. It looks perfectly homoginized (for lack of a better term).

The only really black element in the whole system is the carbon face of the seal. I'll bet the mating surface is worn down. The surprising part is that the particles have to be microscopic in size to mix so perfectly with the coolant.

I've seen carbon faces worn out in industrial pumps and usually there is just black "grit" left in the seal chamber. These however are not closed systems like a bike engine where the fluid gets continuously recirculated. Carbon contamination would explain the odourless coolant.

[Neil E.]

I pulled out a complete spare seal kit to have a look. I thought the mystery part might be a broken piece of the seal spring, but the profile is curved in the wrong direction.

Mikhogl, show us pictures of all the seal parts.

[twowheels]

Originally Posted by Neil E.

One interesting thing is that the black fluid shows no separation in the bottle. If it was oil contamination, I'd expect to see some scum at the top of the liquid. It looks perfectly homoginized (for lack of a better term).

The only really black element in the whole system is the carbon face of the seal. I'll bet the mating surface is worn down. The surprising part is that the particles have to be microscopic in size to mix so perfectly with the coolant.

I've seen carbon faces worn out in industrial pumps and usually there is just black "grit" left in the seal chamber. These however are not closed systems like a bike engine where the fluid gets continuously recirculated. Carbon contamination would explain the odourless coolant.

"homogeneous" is what you were looking for, and I agree. It's doubtful the oil drain will come up with anything but he's got to pull the whole side cover off to get the seal out anyway, so might as well drop the oil.

[mikhogl]

Thanks for all the replies

I have changed the oil 2 times after the impeller was changed and i found no problem with the oil, i also changed the coolant after 10h and it was black again (see attached pix) the coolant is showing some separation now when it has been a few weeks in the bottle (see pix) the piece seems to be made of aluminium. any ideas??

Best regards

[(F5)]

Oh yeah its cast too.

[Neil E.]

Assuming the piece is made of aluminum (or cast aluminum), based on the impeller wear, I'd say that a lot of tiny particles were introduced into the cooling system. Maybe enough that they did not all get out with the last coolant change. That being said, there should have been a reduction in the concentration.

I agree that the next step is to drop the oil and remove the cover to inspect the seal faces. If the seal faces look good, I'd say it's time for some serious coolant system flushing. There could be particles sitting in the bottom of the radiators.

What does the inside of the rubber hoses feel like? Firm and smooth or mushy? What are the chances of a hose breaking down?