e53 coolant leak from back on engine
 

i have removed the metal under tray to try and trace a water leak that i have(4.4), it seems ok all the time i am driving but if i have been on a longish journey then park up i have have a small wet patch left on the drive, i have removed the plastic panel where the pollen filter is and the bulk head panel, i can't see anything but i have been reading about the valley pan, this could be the problem but how else can i check it, my local garage couldn't find it, car is a 2003 with 61000 miles, any help would be great.

Is it the air conditioner condensate draining?

Does the water smell like coolant? If not then admranger is right, it's A/C condensation.

if your coolant is low then most likely it's a valley pan gasket or coolant return pipe o-rings.

If it is coolant, it could be the valley pan, pipe o-rings or the gaskets for the rear coolant accumulator which is that crossover from head to head. I usually change the rear accumulator gaskets and o-rings when doing the valley pan anyways.

the air con has been off for a while until i find the leak, how long would it take at my local bmw specialists to do the valley pan seals? i don't think its a split pipe, i have had a route around with no luck, i need to get it sorted before winter, i have a warrenty from warrenty direct, would this be covered?

Should be covered, just have the dealer send them the estimate and they will either approve over the phone or send an adjuster to take pics for the paperwork. Normally takes a day or so for the adjuster to come, then about a day of labor in the shop. I'd make sure you have the provisions to go without the X for a few days.

ok thanks, i will keep you informed how it went, i will try and get it sorted very soon.

Any update? My X5 seems to be drinkin coolant at 6 oz a day, and there is a musty smell in my car!

My heater hose exploded on the back of the engine couple of days ago. It could be a leaky hose.

I just had one of those hoses on the rear coolant manifold rupture also, but it did so progressively so it wasn't a lot of coolant at first. I also found that a couple of the bolts that hold on that manifold had loosened over time, so I could see that leaking also.

When are these hoses blowing (miles and age)? In other words, when is the appropriate time to change them out so you aren't stranded/

Mine blew at 107K, but I wouldn't change them until they leak. It was so hard to reach, I never laid eyes on the thing until it was out. I could only see it with a mirror.

Maybe long shot but if you smell it inside the car, check your heating core in the back of center console. Did your windshield fog up easily?

2000 4.4 @ 130k

Sorry for the late response, no the windshield did not fog up. I still have the issue, didn't drive the car for a month as I was away with family. Off to indy on Monday...

The same over here. but bolts doesn't seem to be leaking, just little rust thing on it. so didn't want to touch it, It could brake. Hose changed also. But have to check under the car. could be something more.

Back from dealer, turned out to be faulty expansion tank. Removed and replaced!