Yeah, that has to be stop leak... and yes the cap will purge when overfilled.

As for the coolant leak, that is the temperature sensor for the radiator outlet and the o-ring on it is generally not sold separate. What I have found is that a fuel injector o-ring fits and works perfectly, pretty much any bosch style injector uses the same o-rings so you can get one to fit your X5 or a 92 mustang etc.

Weasel, I just replaced all the water hoses I could change myself. There was one that I bought that I couldn't figure out how to access. On my 02 4.4, it is the bottom hose that runs from front of the engine bay to rear along the drivers side of the engine. It is the one that has a metal looking section in the middle of it and the rear dissapears between the back of the engine and the firewall. How the sh!t do you get to the back side of that hose?

Sounds like you'd actually have to drop the skid plate and reach up in there if it runs on bottom. It isn't one of the metal ones that comes up top by the strut tower is it?


http://img171.imageshack.us/img171/9...10220at123.png

Sounds like #10 in this link... in which case long reach tools and/or being a contortionist may help. Trying to remember if that is the one that goes into the side on the rear coolant accumulator/crosspipe... if it is then you will need to remove the microfilter bulkhead to gain more access to it against the firewall.

Yes, it is #10. I replaced #'s 1, 2, 8 and 9 yesterday along with the coolant level sensor. No dealers had #3 in my area and I couldn't wait for parts as my wife needs the car tomorrow. I may just roll the dice and leave #10 until I do a coolant flush in about 2 years and hope that it holds up. It doesn't look bad. The reason I started this project is because hose #1 cracked. I should have known because the connectors were brownish in color.

I may look into removing the microfilter housing and assess the situation again. I can't actually see where it connects. I originally thought it was the firewall, but I don't think that is the case. My radiator, water pump, thermostat and expansion tank are all new within the past 30k miles, so hopefully I will be OK for a while.

Thanks for the advice

Weasel was right. It is the hose marked with the arrow. The one above it goes from the expansion tank to the firewall, which is where I thought this hose ended up originally.

Upon further review, hose #10 is staying put. I just don't have the time or desire to mess with it today.

Weasel, I read you post about opening the bleeder screw and filling with coolant/distilled water mix until it comes out of both the bleeder hole and the cap opening itself, but wouldn't this method leave the coolant level above the cold level line?

EDIT: Sorry, I missed the post where you said the cap would purge itself. Carry on.

If you don't want to let the cap purge the extra coolant out under the hood you can always use a turkey baster style sucker bulb to suck some out of there, no biggie.

BMW Coolant Product Description:

“This product is exclusively formulated and produced by BMW to protect your engine all year round.

It protects against freezing, boil over, corrosion and excessive silicate gel precipitation. This ethylene glycol based antifreeze contains no nitrites or phosphates, greatly reducing the possibility of harmful deposit formation. This coolant is superior to off the shelf brands that contain phosphates. Your cooling system is expensive to replace so use Genuine BMW Coolant.