Water Pump Replacement m52

[Yayrea]

I bought an m52 about a year ago to swap into my e30. The guy said it had about 150k on it and that he pulled it from a rear ended 5 series. Just now beginning to replace all the needed maintenance stuff. I did my thermostat and thermostat housing right before jumping into the water pump and there was the similar colored oil in there. Looks a little worse cause its been sitting in my garage for a year. From what ive seen in videos, it should just be cooland residue behind here, but this looks like oil was definitely mixed in.

But before i put this new water pump in i wanted to ask if this shows any signs of anything i should be aware of before continuing with this engine at all. Could this be signs of blown head gasket or is seeing that oil residue normal? Thanks

Water Pump Replacement m52 BMW by Alex Y, on Flickr

Water Pump Replacement m52 BMW by Alex Y, on Flickr

20200112_135447 by Alex Y, on Flickr

Water Pump Replacement m52 BMW by Alex Y, on Flickr

[TobyB]

That... is disgusting. But since it's on half of the pump. it probably happened after the engine was pulled.

It is unusual for oil to get into water (usually, it's the other way around).

So you could say the glass is half full, and someone did something dumb after pulling it, from
the 3 year old 'helping daddy' by pouring a quart into an open hose to someone thinking
that oil will stave off corrosion (it will)

Or the glass is half- empty, and something ugly happened in the rear- ending process (unlikely)
the trans cooler leaked into the radiator (not unlikely) or something else that won't really mess you up.

Or there's no glass, and the motor's dun blowed up. Unlikely.

Quite hard to test, though, out of a car. Compression and leakdown would be wise,
but won't necessarily catch a breached water jacket. If it was me, I'd hook it up,
and try it.

Being ready to swap or repair it if necessary.

t

[twright]

What does that residue feel like? Is it oily or hard as a rock?

[Yayrea]

What does that residue feel like? Is it oily or hard as a rock?

The oil on the water pump was hard as a rock and crusty. But it's been sitting about a year and a half 2 years. But inside the block I was able to clean a lot of it off with a shop towel.

[twright]

That debris does not look good. A lot of those engines overheated because of a cracked coolant expansion tank. Sometimes the overheating resulted in a bad head gasket and head bolts that were pulled out of the block.

I"m not sure how much you want to investigate this before you put it into the car.