[330istocknot]

I just noticed this leak happening.

I have to drive 4 hours tomorrow and i can tell you this leak has been like this for at least a week. Noticed it when vehicle was asking for coolant.

Long story short, is the top part on picture sold desperately? If so which part is it, and if not, can this be JB welded?

I've used JB weld on metal before, and it works wonders, but plastic, and heat, how would JB weld handle this?

[avocet]

Do you want to seal it for short term to get you through your trip? And if it's been like that for awhile, then you have an educated gamble that it will not fail in the imminent future.

I would try something like scotchweld urethane adhesive... it remains somewhat flexible and it has a fairly high heat range. Just remember to prep the hell out of the area... light sanding with scotchbrite or similar would help with adhesion.

https://www.strobelssupply.com/3m-sc...ml-12-per-case

https://www.strobelssupply.com/media...04ns-black.pdf

[TheMidnightNarwhal]

Fuck it man JB weld everything.

If I'm getting a small crack like that I'm most def putting some JB weld before buying a new part.

Altough might wanna get JB weld for plastic. Also I would check temp specs but I'm sure it can resist that heat.

[Efthreeoh]

You are not leaving yourself many options here based on the situation where you are driving 4 hours tomorrow. The radiator side tank appears to be cracked at the elbow for the upper radiator hose. JB Weld is a 2-part epoxy, which is a thermosetting plastic. It sticks to most materials and can take a good deal of heat. My car currently has the oil vent hose from the rear of the valve cover to the oil separator JB Welded together with a 1/2-inch copper pipe butt-joint connector on the inside (to give it some structure). I fixed it as a field fix more than 24 months and 50,000 miles ago or so.

While that may give you some hope that you can repair your radiator with JB Weld, my fix gives some substrate (the copper connector) and the ribbed hose gives the JB Weld good mechanical grip to adhere to. Your situation is more of a capping over of a crack in the plastic side tank that really doesn't give the JB Weld any mechanical grip to adhere too. I thoroughly cleaned the oil separator hose with brake kleen and then denatured alcohol with a whole bunch of q-tips. I'd bet your radiator has a hairline crack, which is causing the leak. The only way the JB Weld would best work is if it can get into the crack (which needs to be perfectly clean). Etching the hairline crack with a file might help, but at the same time weaken the tank and make the situation worse. To do anything to have the JB Weld work would be to clean the area thoroughly after you've dropped the level of the coolant so there is no liquid in the crack. And you need to rough up the surface of the tank around the crack. And you'd need to let the JB Weld setup and harden for 24 hours. JB Quick can shorten that time, but JB Quick is not as strong as Weld.

Maybe your best choice is to either borrow a car from someone, or rent a car for the trip and properly fix your car when you get back. A new OEM radiator is $166 from FCP Euro.

[Bali]

Another sneaky option is to simply crack open the expansion tank such that the cooling system doesn’t pressurize. Coolant will circulate just fine. Then do your JB Weld trick as it won’t have to hold pressure. Of course, test this out on a long local drive before hitting the road.

FWIW: I once had to drive a car with a coolant leak 100 miles and used that method to get it done.

[desertman123]

trust me I tried, mine broke in that exact spot

it will not hold

[330istocknot]

So far so good.

I JB welded it, whats the worse that could happen before the trip.

Drove to work about an hour drive, checked and it looks strong.

It looks like the crack was on top not on elbow. Seems that coolant dropped to the elbow from the crack. I circled it red on picture below.


What i did is i drained some of the coolant, and left the coolant lid off, for no pressure to build. Then sanded the area around real well, made sure there was no water leaking from the small crack.


JB welded it and looks hard and solid. Im gonna drive home today another hour in traffic, ill see if it looks good and solid i think it might be a go. If i see any coolant (even one drop of coolant) i will rent a car.

Will update you all when i get home from work to see if it held right.

I used the Black and Red JB weld.

[Efthreeoh]

Looks like a decent temporary fix. I'm not sure who suggested keeping the cap loose, but that's a really bad idea. The coolant reservoir is pressurized on the E90. The car would soon over heat and there'd be a hot mess under the hood in short order.

Good luck with your trip.

[hassmaschine]

Originally Posted by BaliDawg

Another sneaky option is to simply crack open the expansion tank such that the cooling system doesn’t pressurize. Coolant will circulate just fine. Then do your JB Weld trick as it won’t have to hold pressure. Of course, test this out on a long local drive before hitting the road.

FWIW: I once had to drive a car with a coolant leak 100 miles and used that method to get it done.

Uhh.. you know that pressurizing coolant is how it can run above the boiling temperature without actually boiling, right?

[330istocknot]

Originally Posted by Efthreeoh

Looks like a decent temporary fix. I'm not sure who suggested keeping the cap loose, but that's a really bad idea. The coolant reservoir is pressurized on the E90. The car would soon over heat and there'd be a hot mess under the hood in short order.

Good luck with your trip.

I think they mean't to take off the cap bebfore JB welding it, so pressure wouldnt build up causing leakage from the small crack. I wouldnt get to the corner without a cap on the reservoir!

Thank you though! I will update you all with how the trip went. Again this is a temporary fix, i will be looking for radiator as soon as i get back.

Have a great weekend everyone!

[gbalthrop]

Originally Posted by BaliDawg

Another sneaky option is to simply crack open the expansion tank such that the cooling system doesn’t pressurize. Coolant will circulate just fine. Then do your JB Weld trick as it won’t have to hold pressure. Of course, test this out on a long local drive before hitting the road.
FWIW: I once had to drive a car with a coolant leak 100 miles and used that method to get it done.

Originally Posted by Efthreeoh

...I'm not sure who suggested keeping the cap loose, but that's a really bad idea. The coolant reservoir is pressurized on the E90. The car would soon over heat...

Originally Posted by 330istocknot

I think they mean't to take off the cap bebfore JB welding it, so pressure wouldnt build up causing leakage from the small crack. I wouldnt get to the corner without a cap on the reservoir!...

+1 BaliDawg

"Vapor Pressure" is what causes a small leak or crack to leak ONLY when engine coolant warms. WHAT pressurizes the pressurized cooling system when the cap is closed? -- Vapor Pressure (AS/AFTER the engine warms). It doesn't magically pressurize itself after you close the cap on a system that has cooled to ambient temperature. Here is a discussion of Vapor Pressure:
https://en.wikipedia.org/wiki/Vapor_pressure

Your thermostat should maintain coolant temp in the ~ 95C/203F range, which is BELOW boiling point of the 50/50 coolant mixture at sea level ambient pressure, so IF the reservoir cap CAN be opened just enough to allow vapor pressure to be released (yet keep liquid coolant from escaping), this proposal will work (as long as coolant temp remains ~205F or less).

I've read somewhere that there is a way that you can cause the thermostat to go into a lower temp opening "limp mode", somewhere around 180F, but I don't know if that is correct, and I've forgotten what needed to be disconnected to do that (BSD connector to Thermostat?). If you have INPA, you can use DME | Activations/Steuern | F1 | F6 (Thermostat/KFK) to open it an leave it there (don't return control to DME). Anyone know if that would present any problem for emergency use?

BaliDawg's idea would work on the old "Lever on Cap" type radiator caps (just raise the lever), but I've never tried it on a cap like the E9x uses with an o-ring seal. I don't know if you can regulate pressure release sufficiently with that. BaliDawg, I take it you did that on a vehicle OTHER THAN E9x? Ever tried adjusting the E9x cap "just so" to do that (without destroying the pressure-relief valve in the cap which is doable in a pinch -- price of new cap less than a tow ;-)

You WOULD slowly lose coolant in Vapor form doing this, but the reduced cooling system pressure would lessen leakage from a small crack or pinhole leak (the pressure is NOT from the pump pumping, but from the Coolant Vapor Pressure). You would NOT have a liquid coolant loss "before you got to the corner", nor a liquid mess in the engine compartment. Removing the cap when the engine has cooled does NOT release pressure from the system, as the vapor pressure decreases with coolant temp until at equiibrium with ambient temp, and now there is NO pressure differential between pressure IN the system, and ambient air pressure (OUTSIDE system).

Your Coolant Reservoir level warning light will tell you if your coolant level drops enough to affect pump performance, and you can activate "Hidden Menu" menu 7.00 and read coolant temp (as measured by the ECTS immediately BEFORE coolant enters the upper radiator hose, OP's leak site (when thermostat is open).

George

[hassmaschine]

E90s run at 80-112c - we dont have a "fixed" operating temp. It can and will run above the boiling point of water.

The system is sealed - it pressurizes when the coolant heats up and expands. When you open the cap, it obviously cant build up pressure. At 112c, even with a 50/50 mix theres a risk that the coolant will boil. Its designed as a sealed system, its not by accident...

[Efthreeoh]

As someone who learned physics at the college level rather than on Wikipedia, and has a degree in manufacturing enginering, I can assure you that trying to run the E9X cooling system open to the atmosphere, the car would soon overheat and spew coolant all over the right side of the engine bay. Anyone who has lost the coolant pump and had an over heating event can attest to what happens. The resivoir cap has a pressure release valve built into it. Keeping the cap slightly unscrewed does not change (lower) the value of when the pressure release valve operates. Keeping the cap slightly unscrewed only provides for an easier path for vapor pressure to escape, which loweres the pressure of the system that in turn lowers the boiling point of the coolant mix. This would actually cause the car to overheat quicker, not prevent it from building less pressure to keep the coolant from escaping from the small crack in the side tank.

There is a reason why all radiator caps state "do not open when hot".

[John 070]

Originally Posted by Efthreeoh

As someone who learned physics at the college level rather than on Wikipedia, and has a degree in manufacturing enginering, I can assure you that trying to run the E9X cooling system open to the atmosphere, the car would soon overheat and spew coolant all over the right side of the engine bay. Anyone who has lost the coolant pump and had an over heating event can attest to what happens. The resivoir cap has a pressure release valve built into it. Keeping the cap slightly unscrewed does not change (lower) the value of when the pressure release valve operates. Keeping the cap slightly unscrewed only provides for an easier path for vapor pressure to escape, which loweres the pressure of the system that in turn lowers the boiling point of the coolant mix. This would actually cause the car to overheat quicker, not prevent it from building less pressure to keep the coolant from escaping from the small crack in the side tank.

There is a reason why all radiator caps state "do not open when hot".

LOL

nobody should be able to leave HS without v = ir, pv=nrt, derive, integrate, etc. One doesn't even have to work with these. Time value of money, demand and supply elasticities, amortize a loan.

When I see the endless mpg threads (why is my car getting such poor mpgs, why is my range so inaccurate), I realize that we have had a problem for a long time.

Maybe this is a little bit of chemistry, but how about the one where people figure 100% antifreeze is better than 50/50? Though I've never done it, 70% is the max, after which anti freeze is worse and starts going the wrong way.

[Efthreeoh]

Originally Posted by John 070

LOL

nobody should be able to leave HS without v = ir, pv=nrt, derive, integrate, etc. One doesn't even have to work with these. Time value of money, demand and supply elasticities, amortize a loan.

When I see the endless mpg threads (why is my car getting such poor mpgs, why is my range so inaccurate), I realize that we have had a problem for a long time.

Maybe this is a little bit of chemistry, but how about the one where people figure 100% antifreeze is better than 50/50? Though I've never done it, 70% is the max, after which anti freeze is worse and starts going the wrong way.

Well, there IS Water Wetter you know...

[330istocknot]

Update: Total hours driven this weekend was 8+, the JB Weld held like a boss. Makes me wanna keep going to see how long it can last. Feels as solid as metal!


Here's a nice pic of the view~

[9krpmrx8]

Poor car.

[mattoak]

How did you fix hold up? I just had my coolant return line break, and then the nipple on that upper radiator connector hose going from the OFH to the radiator snapped off when I was replacing the return line. When I tried to replace the upper hose, the connector on the radiator was stuck and I was prying back and forth for a while before getting it to come loose. Thought all was well, but low and behold two days later I notice a slight leak in that very same spot. I'm at work and I just sanded, cleaned with isopropyl, and dabbed some JB Weld 5-minute epoxy on there. Going to let it cure for an hour and see how she holds up.

Wondering if you ever replaced the radiator or if you're still going on that fix! If mine doesn't leak I'm definitely going to drag my feet getting a new radiator installed.

[Daniel08E93]

Originally Posted by mattoak

How did you fix hold up? I just had my coolant return line break, and then the nipple on that upper radiator connector hose going from the OFH to the radiator snapped off when I was replacing the return line. When I tried to replace the upper hose, the connector on the radiator was stuck and I was prying back and forth for a while before getting it to come loose. Thought all was well, but low and behold two days later I notice a slight leak in that very same spot. I'm at work and I just sanded, cleaned with isopropyl, and dabbed some JB Weld 5-minute epoxy on there. Going to let it cure for an hour and see how she holds up.

Wondering if you ever replaced the radiator or if you're still going on that fix! If mine doesn't leak I'm definitely going to drag my feet getting a new radiator installed.

I did the same thing you did a month ago. Long story short I had to re apply the jb weld a couple times and the crack seemed to just get bigger and bigger for me at least, every 1-2 weeks I found myself applying more and re filling the coolant in the car, was doing that for about 3 months until I had enough and just sucked it up and I changed my radiator out. It was about a 2 hour job for me on just the radiator, I also ended up doing some other stuff as well like fixing an oil leak and changing out my injectors. My recommendation would be to just suck it up and replace the radiator

[nsjames]

it always fails, because the coolant will eventually debond the epoxy from the plastic.

If you need to do this for a temp roadside repair, PC11 epoxy is the most resistant.
I went 6 months on a repaired plastic end tank on PC11 in a EF Honda.
but it will eventually leak from underneath the epoxy, and the epoxy will eventually pop off.

[DrTCii]

Originally Posted by 330istocknot

So far so good.

I JB welded it, whats the worse that could happen before the trip.

Drove to work about an hour drive, checked and it looks strong.

It looks like the crack was on top not on elbow. Seems that coolant dropped to the elbow from the crack. I circled it red on picture below.


What i did is i drained some of the coolant, and left the coolant lid off, for no pressure to build. Then sanded the area around real well, made sure there was no water leaking from the small crack.


JB welded it and looks hard and solid. Im gonna drive home today another hour in traffic, ill see if it looks good and solid i think it might be a go. If i see any coolant (even one drop of coolant) i will rent a car.

Will update you all when i get home from work to see if it held right.

I used the Black and Red JB weld.

Wow. My radiator just cracked today in the same exact location. Luckily I wasn’t too far from home and was able to locate the crack fairly easily. I was considering sealing the crack myself with epoxy rather than taking it into a shop (I figured the repair cost would be pretty costly). Then I found my way onto this forum.

I’m glad that it worked out for you. What’s the update? How long did you keep it going with the radiator since it’s been sealed? Did you end up eventually replacing the radiator? I’d definitely like to know. 👍🏾👍🏾

I’ll attach the photos/videos once I figure out how to post them onto the forum. I’m new to Bimmer Post. 😂😂

[mainbearing]

I used this epoxy as a temporary fix while waiting for a radiator shipped from rockauto. Lightly sand the area and clean with alcohol, allow to dry and apply epoxy.

Worked fine during the couple of weeks before I got to replacing. No seepage under the epoxy then. I am sure it would have gone longer, but I would not consider this a permanent fix.

https://www.permatex.com/products/sp...or-repair-kit/