M52 Water Pump Replacement Finds...

[Yayrea]

Bought an m52 about a year ago to swap into my e30. 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 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. Thanks

20200112_135447 by Alex Y, on Flickr

Water Pump Replacement m52 BMW by Alex Y, on Flickr

Water Pump Replacement m52 BMW by Alex Y, on Flickr

Water Pump Replacement m52 BMW by Alex Y, on Flickr

Water Pump Replacement m52 BMW by Alex Y, on Flickr

[AndrewBird]

How you found any more else where? Oil in the coolant is a sign of a blown head gasket.

[Yayrea]

How you found any more else where? Oil in the coolant is a sign of a blown head gasket.

Just where the thermostat goes too. I havent and didn't plan on separating the head from the block unless I had to. Wanted to just replace the necessities and get it in the e30.

[sebe20]

Just where the thermostat goes too. I havent and didn't plan on separating the head from the block unless I had to. Wanted to just replace the necessities and get it in the e30.

Once it's in the E30 you're gonna bite your ass trying to change anything at all. It's a good messure to flush the whole system before putting a new pump and thermostate on. Also would recommend to change the connectionrod bearings depending on the mileage. Everything over 150k (km not miles) is due to a change anyways.

Pro tip: take the 728i oilsump and pump so you don't have to modify it at.

[Yayrea]

Once it's in the E30 you're gonna bite your ass trying to change anything at all. It's a good messure to flush the whole system before putting a new pump and thermostate on. Also would recommend to change the connectionrod bearings depending on the mileage. Everything over 150k (km not miles) is due to a change anyways.

Pro tip: take the 728i oilsump and pump so you don't have to modify it at.

Noob question, how do I go about flushing the whole system?

Kinda torn about this motor now, didn't want to take the head off unless needed. Just put replaced the valve cover and all that yesredsay. Wish I woulda grabbed a picture of behind the thermostat.

[sebe20]

Gardenhose and tap. Just flush everything out the engine that might still be in there, aswell as the heatercore in the car (thats where all the nasty stuff from the old engine deposited) Just flush it till clean. For the heater core flush it reverse (tapwater goes into the heater outlet)

I didn't bother to tear my M52tu 260k engine apart, either it runs or it gets replaced with a M54, but if you already found oil sludge in the cooling might as well take care of everything.

[twright]

Can you pressurize the cooling system to see if it leaks out anywhere (like the head gasket)?

[Caperix]

It looks like rust from water against the cast iron. Flush as much out with a hose when it is out of the car. Once installed use some flush & drain the block & as much of the cooling system as you can after getting it to temp to clean more. Keep an eye on the reservoir you may need to flush a few times.

[ZekeTheSneak]

Is that a plastic waterpump impeller? If it is it might just be the plastic deteriorating. That or the old one rusted in place, looks broken in the pictures? Inspect the coolant lines like the spyder hose for brown goo. How does the thermostat housing look? Hopefully you didn't buy a milkshake machine...