Hey folks,
Purchased a 2005 R53 for my son recently, did a bunch of work that was obvious - seemed all good to go, until what I thought was our first rain of the season needing to dry off was actually a coolant leak. I've dealt with a water pump leak before on my 06 twice and the culprit was the water pump, however this is way different. The car does not overheat, I did notice the coolant was low when I got it and I topped it off. The strangest part is I cannot smell the coolant when the engine is running, nor can I see any leaking while its running. I park the car, and for HOURS there will be nothing on the ground. Both times I've noticed it, its after it sits for a full day and I pull away from the parking spot. The amount is significant, and I've yet to find where it's leaking from as I haven't seen it dripping from the block, or the radiator. I've recently cleaned up the entire engine bay as well to spot any leaks.

Tomorrow I will do a full inspection before starting it to see if there is any coolant on the ground. Has anyone run into this? It's like after driving, pressure builds up somewhere and then it just vomits some coolant out - but where is the mystery! I'll take some photos and post them on my next check. Thanks in advance to everyone on this forum who helps - I wouldn't still own (nor would I have bought another) an R53 if it weren't for how great this community is!

Thank you!

- Grit

 

Have you seen this currently active thread? : R50/R53 Potential Water Pump Leak - North American Motoring

 

Thanks for the connect. I have not seen that thread, no. I'm waiting for the car to puke so I can see what the puddle is directly under, this time without moving it . WHere is the location of that T fitting? is it between the air intake box and the head?

 

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Although I haven't experienced any real (major) coolant leaks, other than the common expansion tank and cap failure, I did have my oil cooler/coolant hoses replaced. Both hoses were swelled to the point of impending failure.
Should you discover any of the plastic connectors or "T" connectors cracked or showing signs of leaking - if replacement is deemed prudent, I might suggest you replace them with much improved brass or aluminum opposed to plastic.
Below are a few I've purchased as a preemptive measure:
_ _ 3/4" 5/16 3/4 Coolant tank "T" (aluminum)
_ Coolant Hose & Bleeder Connector (aluminum)

Best of luck!

 

@Here2Go @Daftlad The expansion take is new, and there are no signs of leakage coming from the tank or cap. As I had this on my other Mini, was the first place I went to as well. No matter, this will end up getting replaced with an aluminum one just as I did my 06.

So in a strange way, I'm excited to see where the coolant is dripping, but its getting a little dark and will need to get it up on ramps tomorrow to get a closer look at how its getting there. I measured the distance from the license plate to the puddle so I knew where to look from the top end (30" in from the license plate just a little to the driver side from the center of the car). From the bottom, I can see the coolant is dripping off of the power steering pump, and the only thing above that I believe is the oil cooler and there are several hoses that enter/exit/surround it, though I couldn't see those coolant hoses showed any sign of leakage, looking from the top down. What I did see is a small amount on what looks to be the shifter cable (this is an automatic) with some moisture on top of it... but nothing above it has anything underneath it LOL. More to come tomorrow when i have it on ramps.

 

@Daftlad Thanks for the link - this makes me want to throw things lmao.

What connection point would be the area where my top end picture is?

 

Actually, the previous post is for the manual transmission version - here is what I found for the Automatic. I circled the area above where I saw the drippage from. Again, will get a better look tomorrow. Hey BMW, can we get a few more plastic T fittings please - LOL I suspect the 4 output goes to the heater core, and where those number 6's are, that's the area I'm looking at, but again, cant see anything coming from the top, and it must not be dripping from too high because I cant smell anything when the car is running.



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Welp - looks like water pump also *ugh*. Went out this morning to take a look and have a new puddle coming down the front end of the engine and the first puddle also grew in size. None of this surprises me as the motor has 125k 255k on the chassis. Time for all these lovely things. Also needs ball joints, thrust bushings, wheel bearings, and axles. I've done axles on my other one, but never did any of the front end service mode items or dropped the sub frame which looks like will need to happen.

 

The upside- lots of "while you're in there" wrenching can finally get done easier than if not taken apart..Poly bushings - control arm, sway bar and steering rack; wheel bearings / hubs, brakes; struts, hoses etc. Supercharger service of course. Plenty of people with experience / been there done that on this board; one common piece of advice if you haven't yet found it - get OEM quality axles [i.e. GKN]; lots of fitment and quality issues among the aftermarkets, especially spotty among overseas no-name cheapies. Good luck with all this, I know it does seem like a lot.