[Drpoomanchu]

On 8-10-16 I topped up my coolant from Min to Max which is roughly 14ozs or so. Thought it was odd but not unheard of and figured it may not have been topped since car was delivered. I am the 2nd owner of the vehicle for historical reasons and i purchased from a private seller in Oct of 15 with 14,000 mi. I just checked the coolant again yesterday cold of course and just above the Min line again. I topped up again which needed about 14ozs. I have never noticed milky oil or oil in expansion tank. I dipped a piece of paper towel in exp. tank and comes out perfectly blue. There were a few tiny specs of blk deposits but chalked that up to fine debris from the coolant system. I have not pulled plugs yet but planned to replace them soon anyhow. I am running an ER catless D.P. And armytrix exhaust so what smoke/moisture is coming out doesn't seem out of place. Im thinking something is leaking in the engine bay but have never noticed anything. I want to avoid stripping parts off my car to take to the dealer. I plan to open the exp. tank lid and run the car looking for bubbles in the tank but dont suspect i will find any. I have done leak downs and compression checks before but this car seems a bit more complex. Any advise would be greatly appreciated. FYI. I do not drive the car very often the first top up was prob at 18,000 mi and now im close to 22,000. any advise would be greatly appreciated.

[overcoil]

Other people have also suspected coolant loss.
First thing I would not top off the coolant if the level is at the minimum line and would only top off of the coolant was significantly low or none in the expansion tank.

The cooling system in the 235 is more complex and therefore more susceptible to wider range of levels - I understand you added coolant 4K mikes back but that amount and level can throw you depending on ambient temp.

[Drpoomanchu]

Originally Posted by ScottSinger

Other people have also suspected coolant loss.
First thing I would not top off the coolant if the level is at the minimum line and would only top off of the coolant was significantly low or none in the expansion tank.

The cooling system in the 235 is more complex and therefore more susceptible to wider range of levels - I understand you added coolant 4K mikes back but that amount and level can throw you depending on ambient temp.

Ok... I had thought about not adding as you stated. Looking back maybe i shouldnt have. I added when ambient was prob 80F+ back in early august. Yesterday it was prob 45F ambient. It seemed there was some crystalline under the cap. This could have been attributed to me pulling the cap before when the system was warm. When i did this the cap popped. I would assume the cap resets itself or then again maybe it didnt. Are you under the impression that the system may relieve unneeded coolant to level itself.? If so should i draw out the added coolant back to the min line..?

[overcoil]

I would not draw coolant, there is nothing wrong with going to the MAXIMUM level, but if you filled to the very top of the overflow tank that could be messy or interfere with the pressure cap.
I do think like most liquids, internal engine temps along with ambient temps, mean the coolant level can fluctuate and as long as between MIN and MAX the system is fine.

Also it's normal with increased mileage to get oil droplets in the coolant, when things look like chocolate-milk then you have an issue.

[amw896]

I don't think that amount of coolant adding is normal at all for any mileage. Mine is coming up on 23k miles and my levels haven't moved when warm or cold. Could you take it to a good indy shop so you don't have to remove the mods? Do you run anything to monitor temps? With the coolant levels changing so much I would imagine swings in oil or coolant temps as well..keep us posted!

Also, are you running high boost? Could be a gasket leak.

[Drpoomanchu]

Originally Posted by amw896

I don't think that amount of coolant adding is normal at all for any mileage. Mine is coming up on 23k miles and my levels haven't moved when warm of cold. Could you take it to a good indy shop so you don't have to remove the mods? Do you run anything to monitor temps? With the coolant levels changing so much I would imagine swings in oil or coolant temps as well..keep us posted!

I do monitor temps with JB4. Last summer i thought it was getting pretty warm but i cant go back to see temps due to my iphone being stolen last week and my datalogs were on the phone. I think it was around 240F if i remeber correctly. coolant wise and there has been once where oil temp peaked to 244F. Typically sits near 240F. Ive never had any overheating issues or codes. Most recent logs from last week wtr temp between 215F and 233F after short pull. Are the cooling fans quiet on this car because i don't think i have ever noticed mine running very loudly. Does anyone know at what temp the cooling fan should come in..?

[Drpoomanchu]

Map 5 typically so usually doesn't see more than 16 lbs boost.

[overcoil]

You do know the car has a coolant level sensor, I'm not even sure the sensor is in the overflow tank, it could even be down by the lower radiator hose - and that gives you some idea how much coolant can drop before a warning appears.

I googled BMW coolant level and it seems coolant drop is so common some dealers keep a 50/50 mix out by the service writers desk.

I guess anything is possible but your coolant drop reads to be minimal and usual.

[Drpoomanchu]

Originally Posted by ScottSinger

You do know the car has a coolant level sensor, I'm not even sure the sensor is in the overflow tank, it could even be down by the lower radiator hose - and that gives you some idea how much coolant can drop before a warning appears.

I googled BMW coolant level and it seems coolant drop is so common some dealers keep a 50/50 mix out by the service writers desk.

I guess anything is possible but your coolant drop reads to be minimal and usual.

Ok, i guess thats good to know, just didnt seem normal to me.

[overcoil]

I need to ask, you have a warranty and free maintenance plan ?

Will you be taking car to dealer for a free oil change and listed maintenance ?

[Drpoomanchu]

Originally Posted by ScottSinger

I need to ask, you have a warranty and free maintenance plan ?

Will you be taking car to dealer for a free oil change and listed maintenance ?

Yes, I should still have some remaining warranty. The maintenance should have transferred as well

[Taunto]

This amount of coolant loss is typically normal and should try and carry some spare coolant from the dealer around with you if possible.

Coolant loss can happen through evaporation in small amounts of time. If your loosing alot of coolant, then i would have it looked at for any leaks.

On a side note, if the engine is cold - and the coolant is on or just slightly above the MIN mark - your doing fine.. that is normal and where the coolant level should be at. Coolant level should be around Max mark when vehicle is at operating temp.

if your concerned about it tho, doesn't hurt to take it into the dealership and have them inspect for a coolant leak and express your concern about it, wouldn't hurt and could supply a peace of mind as well.

[Drpoomanchu]

Originally Posted by Taunto

This amount of coolant loss is typically normal and should try and carry some spare coolant from the dealer around with you if possible.

Coolant loss can happen through evaporation in small amounts of time. If your loosing alot of coolant, then i would have it looked at for any leaks.

On a side note, if the engine is cold - and the coolant is on or just slightly above the MIN mark - your doing fine.. that is normal and where the coolant level should be at. Coolant level should be around Max mark when vehicle is at operating temp.

if your concerned about it tho, doesn't hurt to take it into the dealership and have them inspect for a coolant leak and express your concern about it, wouldn't hurt and could supply a peace of mind as well.

Ok, I will continue to keep an eye on it. I have only seen it right at the min mark and never drastically below it. Can or does the system control the coolant level and expel any unneeded coolant. ? Does the cap reset itself once it pops.? I tried to take the cap off the expansion tank and it popped when it was warm. I assumed it reset itself.

[Taunto]

You Should typically never take it off when its warm. If you do tho, unscew it slowly and let the air slowly bleed off before unscrewing it completely. if it's warm onscrew it like half turn at most i think.. if you do it fast and its hot and under alot of pressure, it can pop off and damage the cap and possibly the tank it's self.