[Aronis]

Update, checked my dad's car. The cap on the reservoir was CROSS THREADED and that is where the leak is. Prior service they cross threaded it, next service saw evidence of leak, topped off and CROSS THREADED CAP AGAIN.

Ya, love dealer "Service."

Mike

[AHall]

Originally Posted by Aronis

Update, checked my dad's car. The cap on the reservoir was CROSS THREADED and that is where the leak is. Prior service they cross threaded it, next service saw evidence of leak, topped off and CROSS THREADED CAP AGAIN.

Ya, love dealer "Service."

Mike

I believe the same thing happened when I took my car for the oil change. Since I follow this forum I check my coolant periodically and noticed the cap was extremely difficult to remove. It does not appear the threads were deformed as after I finally removed it I have been able to remove and replace. It is one of those things I will probably tell them not to do at future service as I do not want to deal with them damaging it and not accepting responsibility. Fortunately I have no signs of a leak.

[Used2be]

Originally Posted by AHall

Since I follow this forum I check my coolant periodically and noticed the cap was extremely difficult to remove. It does not appear the threads were deformed as after I finally removed it I have been able to remove and replace. Fortunately I have no signs of a leak.

I commented on the difficult to remove reservoir cap a couple of years ago when I first checked the coolant level. I needed both hands on the cap to turn it, and it was resisting until almost all the way off. I used silicone spray on the threads after wiping them down with a damp rag and the cap has been easily turned since. No difficulty with the other reservoir cap.

As with yours there was no deformity of the threads, so no cross threading had been done. I believe the coolant mixture acts as a bonding agent on the threads and causes the turning difficulty. Perhaps the hot environment pushes a vapor up into the threads, coating them? The rubber o rings also add resistance, but it can’t be much. No leaks in my system that I can see, but I’ve had to top up with 4 to 6 ounces of fluid a couple of times over the last 3 years.

[pbonsalb]

If anyone wants my old tank to give to a fabricator to attempt to duplicate in aluminum or steel, let me know. Otherwise I will be tossing it soon. I have done enough heat reduction and shielding that I don’t have any concerns.

For those that do, the cost of the custom tank would be 2 or 3 times that of a new plastic one so a DIYer who stays on top of maintenance and checks regularly under the hood should be fine with periodically replacing the plastic one. It’s those who don’t look under the hood and/or don’t work on cars that could reduce the risk of failure (and potentially much greater damage) or save tank replacement money long term.

[Aronis]

[QUOTE=pbonsalb;29357386

For those that do, the cost of the custom tank would be 2 or 3 times that of a new plastic one so a DIYer who stays on top of maintenance and checks regularly under the hood should be fine with periodically replacing the plastic one. It’s those who don’t look under the hood and/or don’t work on cars that could reduce the risk of failure (and potentially much greater damage) or save tank replacement money long term.[/QUOTE]

since new BMW tanks are not available, that price (2 or 3 times) sounds ok to me...LOL....

Mike

[pbonsalb]

I did not know new tanks are not available. I bought one a few months ago. I am sure they will be available again if they are out of stock.

[Aronis]

Originally Posted by pbonsalb

I did not know new tanks are not available. I bought one a few months ago. I am sure they will be available again if they are out of stock.

I have an order at a BMW dealer and at ECS, both pending, both back ordered.

Mike

(My tank is fine but for a couple hundred bucks I'd rather have one in the garage ready to swap out......)

[AHall]

Originally Posted by Aronis

I have an order at a BMW dealer and at ECS, both pending, both back ordered.

Mike

(My tank is fine but for a couple hundred bucks I'd rather have one in the garage ready to swap out......)

Maybe they have pulled all the inventory back for replacement with the redesigned upgraded tank. What do you think??

[pbonsalb]

Like the oil filter cap? Sometimes BMW takes note.

[Aronis]

LMAO....DOUBT IT......all bought up because of leaks and those who know about risk of leaks. The tank is $130, not a big expense. The damage is thousands when it leaks. Then you get in line to buy all the other parts...........stupid supply chain....stupid COVID........

Mike

[ironbob]

I checked my levels in both tanks and levels were OK, threads on both tanks were corroded, lubed with wd40 silicone to ease future checks. What tank is leaking or do both leak when problems arise? How difficult is it to replace leaking tank? Probably have to remove fluids before replacing, thinking of ordering new tank for potential problems.

[Maverik259]

Originally Posted by ironbob

I checked my levels in both tanks and levels were OK, threads on both tanks were corroded, lubed with wd40 silicone to ease future checks. What tank is leaking or do both leak when problems arise? How difficult is it to replace leaking tank? Probably have to remove fluids before replacing, thinking of ordering new tank for potential problems.

its the big one. Not hard. simply ciphon the fluid from the tank. clamp the hose coming out to prevent leaks. install new tank. refill.

[pbonsalb]

I’d put a towel underneath and tilt the tank up a bit so the bottom port won’t drain out onto the heat shield and down onto the injectors and coils. I was not able to siphon every bit of coolant out of the tank and some remained. What is in the lower hose will drain also and you should not clamp too close to the plastic end. A silicon cork works also.

[ironbob]

Is there a method to remove plastic engine cover without breaking it, looks like it just snaps in, pull from back, front, or sides?

[Aronis]

Here you go.....

If you can figure out why they want you to remove the ECU connections let me know....LOL...looks like you can do it without all these steps.

Mike

[ironbob]

Thanks for the info, do you disconnect the battery? i do not see a need to disconnect the battery.

[pbonsalb]

No need to disconnect ecus or batteries.

[AHall]

Originally Posted by ironbob

Thanks for the info, do you disconnect the battery? i do not see a need to disconnect the battery.

Disconnection of the battery is usually suggested during auto repair. The disconnecting and connecting of connectors could result in damage to the components if they are powered at the time of connection.

[pbonsalb]

You might get a cel for the disconnected sensor if you have not made sure the car is asleep. It does not hurt to disconnect the battery but I usually don’t except sometimes when welding and have never had any issues.

[ironbob]

How do you inspect the tank, it is so crammed in I cannot inspect the seams. do I wait until tank starts loosing a little fluid? Do you have to remove to inspect,pita.

[pbonsalb]

Undo the 2 bolts, loosen hoses from their retainers, and lift it up a bit and look around it with a bright light. It will probably look fine. I don’t think anyone has posted pictures of a cracked tank yet. Some may just be failing at the cap and leaking.

[M5Neededi]

Originally Posted by pbonsalb

Undo the 2 bolts, loosen hoses from their retainers, and lift it up a bit and look around it with a bright light. It will probably look fine. I don’t think anyone has posted pictures of a cracked tank yet. Some may just be failing at the cap and leaking.

Yeah I wonder if the culprit has sometimes been misidentified as cracked tank as opposed to cross-threaded cap?