coolant leak

[we350z]

Thanks - Looks like this suggestion will pay off after all with respect to some nice reference photos and instructions on how to make a pully holder tool! Kudos to the e38 crowd on bimmerboard!

Originally Posted by m5james

Look on e38.org BMW 7-series information and links for more tips on this job. We share the same motor, and pay particular attention to the bleeding as it can be a real headache if you don't do it right. No one replied yet, but you HAVE to use BMW coolant or Zerex G05 because it is phosphate free. I'm due for my cooling system overhaul soon, all new pieces (better safe than sorry), pre-VANOS intake manifold swap, intake gaskets, etc...it'll be like a whole new engine

[we350z]

Will this work? I couldn't find anything for a 2000 there. I'd like to avoid paying $27 + Arnie tax if possible not to mention lugging it back home since I obviously have no car.

03 2003 BMW X5 Coolant Antifreeze - Fluids/Manuals/Misc - OES Genuine - PartsGeek

[Weasel]

Yep, that is the right stuff.

[we350z]

I should be able to get some of this locally:

http://shop.oreillyauto.com/productd...egoryCode=3219

[we350z]

Here is some pics of those coolant tubes:

Auctiva Image Hosting

[Weasel]

Good, now you can see where the tubes slip into that rear crosspipe. That piece in the pics in the link goes across the back of the engine, from head to head. The coolant pipes have o-rings where they slip into that rear crosspipe as well as where they slip into the waterpump.

[we350z]

Yep - I've learned to do as much research as possible and try to find reference pics or at least visualize so I know what I am dealing with. It's all about preperation. I hate surprises - they can be annoying and expensive. I just need the thing fixed before XMAS when I take the journey to Tahoe.

Originally Posted by Weasel

Good, now you can see where the tubes slip into that rear crosspipe. That piece in the pics in the link goes across the back of the engine, from head to head. The coolant pipes have o-rings where they slip into that rear crosspipe as well as where they slip into the waterpump.

[we350z]

I double checked everything tonight just to be sure and took a couple more pics. I'm starting to think the lower radiator hose that connects to the water pump might potentially be the issue though it's hard to tell. Unfortunately I could not get a clear picture of this. It's definitely pretty wet - but it could just be splashing up from coolant leaking on to the fan from the WP. I'm wondering if it would be worthwhile to remove the fan, dry and clean everything up as best I can and run it again while monitoring. I also verified that it doesn't look like the big adjustable wrench recommended in to e38 post i linked to will work since there is not enough clearance between the fan and the water pump pulley. Looks I will need to get a 32mm box wrench for this (as it looks like TIS is showing). I also don't understand how I would get the special tool hooked onto the pulley bolts (for holding the pulley) since the bolt heads seem about flush with the rim of the pulley. All this said - is it possible, or even worthwhile to attempt replacing just the lower radiator hose to see if it fixes the leak without having to remove the fan, water pulley and belt(s)? I guess it would make sense to just replace the lower radiator hose anyway if I end up having to replace the water pump since it's so buried anyway because it will probably end up failing some time soon anyway. Thoughts?

[Weasel]

I got clear picture from those pics, looks to be coming from the front shaft of the waterpump right behind the pulley. Still need to change the waterpump. And for the hoses, yes this would be a good time to change them. For the most part the plastic ends go out first on our hoses, and the plastic part starts turning brownish when they are REALLY bad... If your hose ends are turning color at all the inside of them is coming apart.

[we350z]

Right on - well at least I feel confident now that the problem has been properly diagnosed. Nothing worse then heading down the wrong path and/or doing work unnecessarily (though i would think the original WP with almost 75K would be near death anyway). The only hose that is exhibiting brown plastic that see is the one going to the rear of the engine bay from the expansion tank. I can't see the connection points on the WP yet. Might as well do them all based on what I am reading on this forum.