Quick water pump swap question - 2001 740iL

[jpilk99]

I'm swapping out my current water pump with a new one, (haven't done this before), and not sure of something: There is a pipe (aluminum?) running pretty much horizontally in front of the water pump and ...doesn't look like I can remove the water pump with this pipe in the way. Do I need to remove this pipe (see picture)? What is it?

Thank you!!!

Jay

[asianvenom]

You can remove the pipe, but i was able to wiggled it out without the pipe removed.

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[jpilk99]

You can remove the pipe, but i was able to wiggled it out without the pipe removed.

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What is it though?

[asianvenom]

Exhaust recirc pipe

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[sealbeach740]

To add to what asianvenom stated, the pipe can be taken off without harming or spilling anything. That does make it easier to R&R the water pump.

[jpilk99]

Thanks all

[jimoreno]

Is actually the secondary air system (injects air the first minute or so when starting cold). It only has two bolts (one at each end) and a clamp i n the center holding it own. You'll need to remove the vacuum hose to the valve and the air injection tube.

[jpilk99]

Is actually the secondary air system (injects air the first minute or so when starting cold). It only has two bolts (one at each end) and a clamp i n the center holding it own. You'll need to remove the vacuum hose to the valve and the air injection tube.

Thank you!

[asianvenom]

You're right...air injection not exhaust recirc

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[jpilk99]

Got the old water pump off and cleaning everything (removing old gasket remnants, etc.) before installing the new one, but, a couple of questions:

1. I did not get a new ...plastic flange/washer or o-ring for the outlet tube below the thermostat (see pictures). The ones off the old pump seem okay, but, feels like I should order these and not re-use the old ones, right?
2. Do people put any grease on the rubber o-rings before putting everything back together?

Thank you.

Jay

[jpilk99]

Got the old water pump off and cleaning everything (removing old gasket remnants, etc.) before installing the new one, but, a couple of questions:

1. I did not get a new ...plastic flange/washer or o-ring for the outlet tube below the thermostat (see pictures). The ones off the old pump seem okay, but, feels like I should order these and not re-use the old ones, right?
2. Do people put any grease on the rubber o-rings before putting everything back together?

Thank you.

Jay

Just read my Bentley manual and it says to use a "water-based lubricant" for the o-rings. I just don't know what a "water based" lubricant is. White lithium grease.

[jpilk99]

Just read my Bentley manual and it says to use a "water-based lubricant" for the o-rings. I just don't know what a "water based" lubricant is. White lithium grease.

(Big tangent) The whole reason I took my water pump off is that I'm leaking coolant. I can see it dripping, quite steadily, down by the power steering pump. I can't see where it's coming from, but I ASSUMED it was the water pump. When I took the serpentine drive belt off, I tugged on the fan and there was virtually no play. I guess it's possible that the gasket failed behind the water pump, but, when I took it off, I couldn't really see any signs of coolant leaking out. (Doesn't mean there wasn't, I just didn't see it).

Now, as I go to put the new water pump on, ...I'm even wondering if that was the problem. With the old one on the bench, I'm pulling on the front of the pump where the fan clutch connects and ...there ain't no play. Does this likely mean the water pump is/was not the source of my leak? Maybe the valley pan?

I guess there's one way to find out, put it all back together, fill with coolant/bleed system and run the car. Just curious if anyone has any thoughts. Thanks.

[DrkWrldCscdr]

Valley pan gasket possibly? It fills with coolant and could leak down the front of the engine when nosed down hill

[xboss]

Just read my Bentley manual and it says to use a "water-based lubricant" for the o-rings. I just don't know what a "water based" lubricant is. White lithium grease.

I think they mean glycerin.

[thrawn5499]

I am going through the exact same thing with my 2001 740il. I thought it was the pump, but when I took the old one off it looks and feels like it is in good shape. Put the new one on and hoping it fixes it. I also had to replace the expansion tank. It looked fine but when I took it off it was full of debris. Broken plastic and an o ring fell out. I also had to remove that metal line in front of the water pump. There was no way for mine to come off with out removing it. It was easy though only 2 bolts, the one on the left was hard to see, but easy to pull off and put back on. (As long as the tip of something that you use to line up the hole doesn’t break off in the hole on the left that you can’t see) if this happens it might take about 4 hours of work to try to get that broken piece of something out of the hole. Please don’t ask how I know this.

Hope that water pump fixes yours, and mine. Good luck


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[racer2086]

To answer a few questions...

Water pumps can fail in a few ways. One is the internal shaft seal leaks. When this happens, the coolant leaks out a weep hole in the bottom of the pump and drips down your engine. Good possibility that is what was happening. The bearing may be fine in this case also, until you run the pump long enough that the coolant gets into the bearing and destroys it.

The o-rings you have there are probably from inside the coolant hose you hook onto that fitting. The o-ring is part of the hose, not the pump, and I'm not sure if they are sold separately or if you need to get a new hose.

***Make sure you get the good BMW water pump gasket (the green one with the black bead on it)!!! The paper ones that come with the pumps suck.

[acspecialists]

I just did my TCG's and replaced all of the little hose over by the PS pump. That is where I would look for your leak. There are three hoses and a thermostat for the trans oil cooler. Unless I was in there already I would have ignored them. As for the water pump if you can't hear it or see a leak getting thrown around the engine compartment it was probably fine. If you look down past the throttle body you can see a small part of the valley pan and coolant will show up there. If the leak is down by the back of the engine that could also be the valley pan, accumulator, heater hoses or the cover on the back of the block.

Good luck, be patient and don't throw parts. Find the problem and fix the problem. Enjoy driving your car inbetween service.