Heat exchanger coolant low

[Likeanowl]

Just did a random check today and noticed the larger coolant tank is low. Not empty, but very low. Any idea what would cause this? The smaller tank that’s located up by the wipers was full but the larger tank closer to the front was low. I haven’t seen any coolant leaking under my car and it seems to be running at normal temp. This wouldn’t be from the top mount cracking possibly could it? I thought the two were separate systems.

[niquehawk5]

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

Good luck.....hopefully you caught it soon enough.

[BzsBimmer]

Keep an eye on it. You could have slow leak at fins from front radiator causing a leak and evaporation during load.

If you haven’t seen any drips of coolant on your floor when parked for a while it could be an indication that it’s only leaking under load.

I believe they are split systems iirc.

*edit
Also are you seeing any coolant residue around your expansion tank seams? If so, that’s probably a good indicator where it’s going.

I did a write up on replacing. Pretty easy job.

[Likeanowl]

Originally Posted by niquehawk5

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

Good luck.....hopefully you caught it soon enough.

That’s for the top mount charge cooler. That tank was full. The larger, lower tank closer to the headlights is what was low for me. I believe (but could be wrong) the top mount intercooler and the front mount heat exchanger are two separate systems.

[Likeanowl]

Originally Posted by BzsBimmer

Keep an eye on it. You could have slow leak at fins from front radiator causing a leak and evaporation during load.

If you haven’t seen any drips of coolant on your floor when parked for a while it could be an indication that it’s only leaking under load.

I believe they are split systems iirc.

*edit
Also are you seeing any coolant residue around your expansion tank seams? If so, that’s probably a good indicator where it’s going.

I did a write up on replacing. Pretty easy job.

As of now I’m seeing no evidence of leaks anywhere. I checked about as well as I could without taking anything apart or having it on a lift. The tank isn’t empty, it’s just low.

[niquehawk5]

Originally Posted by Likeanowl

That’s for the top mount charge cooler. That tank was full. The larger, lower tank closer to the headlights is what was low for me. I believe (but could be wrong) the top mount intercooler and the front mount heat exchanger are two separate systems.

Ahhhh....well thats "good" news. Misread your post.

[hC1001]

Originally Posted by Likeanowl

That’s for the top mount charge cooler. That tank was full. The larger, lower tank closer to the headlights is what was low for me. I believe (but could be wrong) the top mount intercooler and the front mount heat exchanger are two separate systems.

Your terminology is a little off.

The top mount intercooler, heat exchanger(for top mount) and passengerside bumper radiator is the low temp system.

The engine radiator and driverside bumper radiator is the high temp system that you are currently experiencing low coolant. When is the last time the system had been worked on or level checked? There could've been air in the system that finally moved its way to the tank and caused the level to go lower. You should fill it back up and recheck it after a couple miles. Try to refill and see if it stabilizes. If it never stabilizes, there is a leak somewhere... common leak point is the tank seams. If you see dried coolant around the tank seams, use a damp towel to clean it off and monitor it. If you see low coolant level again as well as dried coolant around the tank, you will need to replace the tank.

[Likeanowl]

Originally Posted by hC1001

Your terminology is a little off.

The top mount intercooler, heat exchanger(for top mount) and passengerside bumper radiator is the same system.

The engine radiator and driverside bumper radiator is another system that you are currently experiencing low coolant. When is the last time the system had been worked on or level checked? There could've been air in the system that finally moved its way to the tank and caused the level to go lower. You should fill it back up and recheck it after a couple miles. Try to refill and see if it stabilizes. If it never stabilizes, there is a leak somewhere...

Thanks for the correction. I’m topping it off today and will check back tomorrow. Let’s hope it’s just low and not leaking.

[landonvan]

This should help you understand your cooling system. The top reservoir is for the front mount heat exchanger and the top mount intercooler. The lower reservoir is your engine coolant. If you haven’t checked that one in a while then it could be low. You do loose some over time with the heating and cooling the engine does. Like others said. Fill it and check it in about a week.

[scoale]

Originally Posted by landonvan

This should help you understand your cooling system. The top reservoir is for the front mount heat exchanger and the top mount intercooler. The lower reservoir is your engine coolant. If you haven’t checked that one in a while then it could be low. You do loose some over time with the heating and cooling the engine does. Like others said. Fill it and check it in about a week.

You really did an outstanding job on this video

[jagus]

Originally Posted by Likeanowl

Thanks for the correction. I’m topping it off today and will check back tomorrow. Let’s hope it’s just low and not leaking.

Hello! Did you manage to find the issue with the low coolant level?

[Kilabyte]

Originally Posted by jagus

Hello! Did you manage to find the issue with the low coolant level?

It's always the same thing, leaking intercooler. Same thing happened to me.

[Dabeamerking]

Originally Posted by Kilabyte

It's always the same thing, leaking intercooler. Same thing happened to me.

For him it wouldn’t be the intercooler. He specifically state the auxillery coolant was full and that the main reservoir was low. Therefore this pertains to the main radiator and engine and turbos.

[Dabeamerking]

Originally Posted by jagus

Hello! Did you manage to find the issue with the low coolant level?

Leaking Low Coolant in main reservoir can be a lot of things. Engine, turbo main radiator, heat exchanger, water pump

[Kilabyte]

Originally Posted by Dabeamerking

For him it wouldn’t be the intercooler. He specifically state the auxillery coolant was full and that the main reservoir was low. Therefore this pertains to the main radiator and engine and turbos.

Ah, reading 101 not even once.
I simply saw the title and figured it's 99.9 percent of these cases.