Couple Cooling system questions...
 

Hello! I'm not too active on here, but I've got a few questions someone might be able to answer.

So I found my X5 dripping coolant last night and today I decided to pop the hood and see what blew. After some poking around I determined that the upper rad hose connection to the Thermostat/Waterpump was leaking.

I'm new to the X5, but not new to BMWs (I have an E46 and E39). As usual preventative maintenance is the name of the game. On the E46 the expansion tank is the Achilles heel of the cooling system, as is the radiator on the E39. What are the common E53 cooling system failures? Water-pump and thermostat were replaced in 2012 and I'm replacing the upper and lower rad hoses. The X5 cooling system is much more complicated than my E46 so I'm at a bit of loss as to which hoses I should replace in addition. Car is an '01 X5 4.4i with 80k on the clock.

I've also got a clunk that I've narrowed down to my swaybar + endlinks and a SES light (that's no longer intermittent) due some vacuum leak. Have to take care of all that, stick in some fresh fluids, and hopefully it'll be ready for winter.

There was just a big debate on the forum about this exact thing. From what I understand, the E53's system is just as crappy as the E39's. There appeared to be two camps, 1) replace it all at once, 2) replace stuff as it fails.

Really it comes down to your preference. I'd check the other components but would probably just replace the hoses for now.

Dont worry, the 2 bar cap on these models ensures that any weak spots in your system will be soon apparent. But at least you wont lose coolant between component failures lol!

But seriously, I'd replace it all at once, or as much at a time as possible. I tried piecemeal and I just ended up replacing stuff soon after the other, wasting time and coolant.

JMHO. Others have noted they are on original hoses still, so your call. E46, E39, and E53 are pretty similar to each other, your experience with them is applicable.

+1 just change them all. I am waiting for a set of replacement hoses for my 4.6is. All of the hoses at the back of the engine are very soft and leaky.

The V8 M62TU is basically the same M62TU across platforms (e38/e39/e53)...same for the I6 M52/M52TU/M54 platforms (e46/e39/e53).

The owners of these engines generally experience the same engine-related failures across the multi-platforms these engines are installed in. So a DIY or common failure on an e46/e39/e38/e53 forum will pretty much apply to all when it comes to comparable engine systems.

:iagree:

Still don't know what engine the OP has.....

It was buried near the end of the 3rd paragraph. See quote below: :D

Your hoses and plastic components are nearly 15 years old - replace them all. Carefully inspect the radiator as well. Because of your geographic location and potential exposure to corrosive salt spray on winter roads, the radiator may show evidence of possible failure points and should also be considered for replacement.

Not a cheap endeavor, but the peace of mind and enhanced reliability is worth it.

2002 X5 3.0 291,400 miles
2014 428i 13,000 miles

2004 325i sold at 123,600 miles
2001 325i sold at 66,000 miles

Yep, see that now, my head cold is eating my brain away:
"Car is an '01 X5 4.4i with 80k on the clock."

At 80K, think engine exterior issues, all the above posts will guide you. Mostly it is just a simple inspect, test, and replace as necessary. Belts and hoses are cheap insurance as are the belt tensioners. When the belts are off the W/P will expose any bearing (really just a brass bushing) shaft play - Just wiggle the front shaft - Movement? Replace.

Internally there are cooling tubes that leak. I personally would pressure test the system before any parts replacement to see what if anything else is leaking. After that little test, everything that is replaced as a preventative is up to your skills and pockets.

When it comes to parts there are really two paths - OE/OE Replacement quality and lots of other untested/unknown and possibly really cheap stuff.

All of them will fit (mostly) the OE/OE Replacements will last a long time the others are just cheap to buy and maybe install. Lots of options.

Are you planning to DIY or have a shop do it for you (DIFM)?

Our X5 3.0 expansion tank cracked open when the wife took it out to do errands. Lucky she was parked so it didn't overheat the engine. Had it towed to my house and ordered parts and I replaced few days later. Fairly easy DIY and I've down them on my E39 and E46. The PO replaced the WP, thermostat and hoses but not the expansion tank and radiator.