Charge Cooler: Leak? or Evap?

[icebiker]

Have been following and participating in the Charge Cooler threads, including the below, and watching my reservoir level closely.

https://f80.bimmerpost.com/forums/sh....php?t=1570544

My understanding is that it's a closed system, so the level of coolant should never change. Is this the case? The manual does indicate a procedure for topping it off, so on that basis I would have to assume some minor/occasional fluid loss due to evaporation is normal.

Reason I ask is that earlier this year, after a year (and 6,000 miles) of ownership I noticed a VERY slight drop in level (like two "rings" or "lines" on the yellow indicator). I had the system pressure tested at the dealer in July (it passed). They topped off the fluid and now, 2 months and 1,200 miles later I see its dropped about 1 ring. It has been a very hot summer in the NE, so perhaps that's a factor, but if anyone could clarify whether it's normal or not for the fluid to periodically drop in small increments I'd appreciate it. If it's not, I'll bring it back to pressure test again. If the cooler is going south, I want to have it replaced before CPO expires.

Car is a 2016 F83 6MT, 23 Kmiles. CPO till November 2020. Thanks

[Jbonly21]

Originally Posted by icebiker

Have been following and participating in the Charge Cooler threads, including the below, and watching my reservoir level closely.

https://f80.bimmerpost.com/forums/sh....php?t=1570544

My understanding is that it's a closed system, so the level of coolant should never change. Is this the case? The manual does indicate a procedure for topping it off, so on that basis I would have to assume some minor/occasional fluid loss due to evaporation is normal.

Reason I ask is that earlier this year, after a year (and 6,000 miles) of ownership I noticed a VERY slight drop in level (like two "rings" or "lines" on the yellow indicator). I had the system pressure tested at the dealer in July (it passed). They topped off the fluid and now, 2 months and 1,200 miles later I see its dropped about 1 ring. It has been a very hot summer in the NE, so perhaps that's a factor, but if anyone could clarify whether it's normal or not for the fluid to periodically drop in small increments I'd appreciate it. If it's not, I'll bring it back to pressure test again. If the cooler is going south, I want to have it replaced before CPO expires.

Car is a 2016 F83 6MT, 23 Kmiles. CPO till November 2020. Thanks

Any amount of drop in fluid, is leaking. You could have a very small leak that hold up under normal drive, pressure test is not always accurate. One way to find out is to top off fluid to proper level, then go on a 2 hours sprint drive and push the car. After the drive if it's low, there goes your answer. That's how I found out mine was leaking.

[deeldoo]

Originally Posted by icebiker

Have been following and participating in the Charge Cooler threads, including the below, and watching my reservoir level closely.

https://f80.bimmerpost.com/forums/sh....php?t=1570544

My understanding is that it's a closed system, so the level of coolant should never change. Is this the case? The manual does indicate a procedure for topping it off, so on that basis I would have to assume some minor/occasional fluid loss due to evaporation is normal.

Reason I ask is that earlier this year, after a year (and 6,000 miles) of ownership I noticed a VERY slight drop in level (like two "rings" or "lines" on the yellow indicator). I had the system pressure tested at the dealer in July (it passed). They topped off the fluid and now, 2 months and 1,200 miles later I see its dropped about 1 ring. It has been a very hot summer in the NE, so perhaps that's a factor, but if anyone could clarify whether it's normal or not for the fluid to periodically drop in small increments I'd appreciate it. If it's not, I'll bring it back to pressure test again. If the cooler is going south, I want to have it replaced before CPO expires.

Car is a 2016 F83 6MT, 23 Kmiles. CPO till November 2020. Thanks

I had mine too, the head of the shop there told me that very slight coolant loss is expected.

The only way to find out is pressure test it and also check the J pipe for signs of leaky intercooler.

[icebiker]

Originally Posted by deeldoo

I had mine too, the head of the shop there told me that very slight coolant loss is expected.

The only way to find out is pressure test it and also check the J pipe for signs of leaky intercooler.

Thanks folks. Will do and will check back. In meantime, regarding the J pipe, and forgive me if this is a dumb question, but what would the typical problem be? I assume a crack? Also, if it were to have one, is that a possible cause for fluid to be slightly low? I understood that the J pipe carries air flow, not fluid, no I'm not sure I follow why a possible J Pipe problem would impact fluid levels. Thanks.

[deeldoo]

Originally Posted by icebiker

Thanks folks. Will do and will check back. In meantime, regarding the J pipe, and forgive me if this is a dumb question, but what would the typical problem be? I assume a crack? Also, if it were to have one, is that a possible cause for fluid to be slightly low? I understood that the J pipe carries air flow, not fluid, no I'm not sure I follow why a possible J Pipe problem would impact fluid levels. Thanks.

No, the assumption and logic is that a faulty intercooler (2k+ fix) would result in not just airflow going into your J pipe but also coolant.

So by inspecting the J pipe and finding coolant or traces of it you will know your intercooler is deaded. The J Pipe won't have cracks or leaks.

If you find a completely perfect J Pipe then it is highly likely if there is a leak that it would be in the reservoir which is a cheaper fix.

Also there is an off chance that some portion evaporates over a very very long time and you never bothered to check it.

[Beemerm3]

My old Mercedes cls550 biturbo had leaked coolant. All the time eventually I would sell it and bought a bmw m3 and now this problem again. But I’m thinking of buying an eBay intercooler if it leaks.