Coolant Leak - where is this coming from?

[carcar123454321]

I've only had the car for about a week and have been checking it over, changed the oil, etc. On about the 4th drive I got a coolant leak (or should I say I noticed it).

1. Any idea where exactly this leak is coming from? Left about 3-4 ounces on the garage floor.

2. Should our car's coolant run at around 240 degrees? That seems high but mine runs just under the 240 mark.

Sorry, I'm not sure how to resize the photos in the forum (maybe just change before uploading?) so they're pretty large.

https://ibb.co/ZhKM73w
https://ibb.co/JcfvyK5
https://ibb.co/LttNpQ2
https://ibb.co/2MMDh9t

[clueby4]

maybe try the coolant bleed procedure to see where it’s leaking?

Make sure your coolant reservoir is topped up.
Press the start button twice without feet on any pedals so engine is off but ignition is on.
Turn a/c fan onto lowest setting but temp to max.
Press gas pedal till you hear the water pump start (somewhere between 10 and 20 seconds)

Hopefully this will help you locate the leak? Advisable to do it when the car is cold.

For better visibility i’d take the air intake off the airbox. 4 screws holding it in place at the front of the engine bay (marked in red) and two clips holding it onto the the airbox (marked in green)

edit: my money is on the hose connecting underneath the top radiator hose marked red in the second pic attached

[carcar123454321]

Thanks much! Will try that.

Are there any better aftermarket hoses (silicone, etc) or do people just replace with BMW?

[tracer bullet]

I've always checked sites like FCP Euro (as an example, many great shops are out there). They often have true OEM in OEM boxes, as well as identical items form the companies that manufacture for the OEM's. And of course those parts are cheaper.

The 240-ish degrees is normal. That's actually the oil temperature but after a while of driving in the summer yes totally normal.

Good luck with the coolant part though. I'd just generally say to clean the area up and hope that might help spot it the next time it starts to leak. There are also dyes you can use, later with a black light, to try and find the leak.

[carcar123454321]

I really think it’s coming from here, and doing it when it’s under higher temps/pressures as the coolant bleeding wasn’t quite enough to make it leak.

Not sure if it's the lower hose (joint #2), or the connection between the lower and upper one (joint #1). Looks like there may be some dried coolant in the clip that locks the two together which would make me think more the upper joint but hard to tell. I may just buy both hoses if there's a chance it's the connection.

I guess there's some dried coolant on the upper hose to radiator too...that could have been from previous maintenance though. I need to clean it all off really well.

I'm going to also check coolant temps...it couldn't possibly be "overpressurizing" the system and blowing past perfectly good seals could it?

[clopez1]

Just an FYI, i’ve recently had to replace this exact hose and found that two oe/oem (rein, oes) manufacturers don’t fit as well as the genuine BMW part for this specific hose.

[carcar123454321]

So..... cleaned it all up, drove a little to get it hot, then checked.

1. Before I replace items I want to make sure the system isn't over pressurizing/overheating. On the drive the coolant temps (hopefully my little app gauges are accurate) went between 220 and 240. 240 seems awful high or does the N55 run that high? I wasn't driving it real hard either.

2. Looks like there's a slight hairline crack in the radiator where it connects to the hose on the driver's side. It was unnoticeable except I would dry it off and coolant would start magically appearing at the hairline crack.

3. Not sure if the hoses that I posted before are even leaking or it's just from the hairline crack...hard to tell if it's the hairline crack dripping down or another leak at the joint that I posted above.

I'll start looking, but are there all aluminum upgraded radiators without plastic? (If I had the cash I'd get rid of most of the plastic...charge tubes, intercooler, radiator, etc.)

[tracer bullet]

1 - Yes, normal, see what I said earlier
2 - Nice job, sucks to have that crack but if coolant does appear there, it's a good chance you've figured it out
3 - Good chance they are just downhill and it's run to them, if you are seeing them stay dry then you're probably right

For the last one I cannot say but would again start checking the sites for what's available. If it exists and fits they'll have it. FCP Euro, ECS Tuning, Bimmerworld, etc.

[carcar123454321]

Thanks again! Would you recommend (if you have a recommendation):

1. Non-OEM replacement (plastic, etc.) - around $200
2. BMW brand - around $400
3. Upgraded all aluminum performance radiator - around $500-$600

I'm tempted to just bite the bullet and go all aluminum. I'm not fond of the plastic ended radiators and ICs--just a blowout or crack waiting to happen ;-)

[tracer bullet]

If #1 is the same manufacturer (and the same part) as OEM, it's probably what I'd do. Generally they are good quality, even if in your case there was a crack (which may have been spontaneous or a result of some earlier forces or something applied). Identical item for half price. Chances of an issue maybe 1 : 100, maybe 1 : 1000.

The all aluminum sounds great if you don't care much about cost (seems like you do), or if you're racing and need an upgrade (unknown).

Straight OEM I might skip for the needless cost increase.

[carcar123454321]

240 was the coolant temp not just the oil temp…is the coolant supposed to get that high?

[tracer bullet]

Originally Posted by carcar123454321

240 was the coolant temp not just the oil temp…is the coolant supposed to get that high?

I don't think the coolant can get that high, no, even with 50/50 glycol or whatever mixed in it. Above boiling, yes, 220F maybe, but not that far. If you measured 240 F you measure a steam pocket.

For coolant temp you're needing another gauge, maybe software, talking to your car while you are driving to get live readings. If you are referencing the gauge in your picture, that's the oil temp.

[carcar123454321]

Sorry I forgot to post a pic, but it's a gauge on my phone using one of the PIDs and bluetooth...it may be the wrong PID though (maybe oil like you're suggesting) as it's a generic program "Autometer". I think under pressure the water can go somewhat higher but I agree that would be extremely high and I would think would trigger some temp alarm.

I got a little worried about the plastic ends as some on FCP were saying they had them go out in just a year or two after putting a new one in.

[clueby4]

Originally Posted by carcar123454321

Thanks much! Will try that.

Are there any better aftermarket hoses (silicone, etc) or do people just replace with BMW?

I replaced all my coolant hoses last weekend coincidentally, after my mickey mouse hose decided to disintegrate when sneezed on.. I went with the reinforced silicone full hose set from Vargas Turbo (mostly for aesthetic purposes, I'll admit, but the billet aluminium connectors coupled with silicone was a BIG plus). Whilst they weren't cheap, I could not be happier with the quality and fit (i'm not affiliated with VTT in any way, but I am a happy customer).

They were easy to fit except for the horseshoe, which was a proper PITA to get to. The bottom end of the mickey mouse was painful due to the orientation of the hose clamp. I suspect it was installed whilst the engine was out of the car originally.

Definitely a job I never want to have to do again.

edit: a couple of pics

[carcar123454321]

Nice! Holy cow, I bet that was a lot. I replaced all mine on my Solstice GXP with silicone and it was a job as well, but no worries now about every having a hose issue. Good to know if I decide to tackle it.

I know it's a weight and a cost thing, but I always think about how little it would cost the manufacturer to just do all this at the factory---massive volume discounts, easy to put it all on, etc...and those parts would be bullet proof (charge pipes, coolant lines, etc.). Oh well.

[carcar123454321]

Looks like they may only make the silicone set for the N54 and not the N55...I'm checking.

[carcar123454321]

Another tip: Just buy a coolant pressurization test kit from Amazon or Harbor Freight and pressurize your system and look at all the leaks without having to heat up the coolant.

For example: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[carcar123454321]

Humorously, I decided to temporarily try to patch the seeping seam (about 1") by roughing up and JB Welding it (just the Quick Set JB Weld)---did one thick layer and one more on top. I've driven it now about 50 miles with no issues whatsoever--bone dry on outside. I don't think this would work for a big leak, but for a seep on a plastic part you can get to, I'm pretty impressed.

I'm still replacing it of course, but I half want to drive for another 100 miles just to see ;-)

[beamer135i]

Hey, just wanted to check with you; how's that JB weld holding up? Or have you already replaced the radiator? My radiator has a hairline crack identical to yours, I'm contemplating the JB fix so I can get around close to home temporarily until replace the radiator. A radiator replacement will be a big project for me so I'll need to be sure I have backup transportation.

[carcar123454321]

If it's just barely seeping, I'm convinced JB Weld KwikWeld (sets in like 5 minutes) is a great solution. It's now held like 6 months and I did a similar repair on my Suburban with the same success.

1. Make sure coolant is cool and not pressurized
2. Clean throughly, rough sand with like 100 grit, clean again
3. Mix epoxy
4. Dry thoroughly just before applying epoxy
5. Apply one layer going well outside of seeping area
6. Let harden for say 20 minutes
7. Apply second layer again going way outside seeping area
8. Let harden overnight
9. Drive!

On another note Vargus only makes the cooling lines for the N54, not the N55 (I messaged them) so I guess it's stock lines for me.

[beamer135i]

I degreased the area, roughed it up pretty good; (it won't talk back anymore) and was ready to apply the epoxy...I ordered the epoxy from Amazon before I read your latest comment...😕 I bought the putty epoxy cuz it can withstand high heat up to 500°. After working it, kneading it between my fingers I realized it's too thick for this application, and Amazon won't let me return it.😭 I'm going to get the Kwik Weld and report my success...I hope. Thanks for your response. 👍🏼