[slay2k]

Posting here cause I'm pretty sure the regulars here are more knowledgeable.

So 3.5 months ago (May 1st) I got a "coolant level low" yellow light and topped off my reservoir with 100% distilled.

Yesterday I was highway driving in 100 deg weather and the car gave the red overheat sign and went limp mode. Oil temp showed a measly 250 (my norm is 230-240) and I'm surprised because I keep reading all you guys run like 250-260 without shutdowns. Anyway, I restarted after 5 min + turned off AC and drove it just fine at 240 for over an hour to get home.

Checked coolant level today -- low. The top sphere of the float is barely clearing the bottom of the plastic cylinder. Planning on refilling w/ more distilled but also wondering where this coolant is going in 100 days time and would appreciate all ideas on diagnosing. Could a leak this slow be from the water pump?

Looked around the engine bay and see no leaks except a little fluid from the top of the power steering reservoir. I also took a look in my wheel well and found empty space where the oil cooler would be so I don't believe I have one ;/

Am I right to assume the shutdown was triggered by the thermostat (so coolant temps?) How would you guys advise diagnosing the loss of coolant and the overheating shutdown?

Thanks in advance.

[Jeff@TopGearSolutions]

Originally Posted by slay2k

Posting here cause I'm pretty sure the regulars here are more knowledgeable.

So 3.5 months ago (May 1st) I got a "coolant level low" yellow light and topped off my reservoir with 100% distilled.

Yesterday I was highway driving in 100 deg weather and the car gave the red overheat sign and went limp mode. Oil temp showed a measly 250 (my norm is 230-240) and I'm surprised because I keep reading all you guys run like 250-260 without shutdowns. Anyway, I restarted after 5 min + turned off AC and drove it just fine at 240 for over an hour to get home.

Checked coolant level today -- low. The top sphere of the float is barely clearing the bottom of the plastic cylinder. Planning on refilling w/ more distilled but also wondering where this coolant is going in 100 days time and would appreciate all ideas on diagnosing. Could a leak this slow be from the water pump?

Looked around the engine bay and see no leaks except a little fluid from the top of the power steering reservoir. I also took a look in my wheel well and found empty space where the oil cooler would be so I don't believe I have one ;/

Am I right to assume the shutdown was triggered by the thermostat (so coolant temps?) How would you guys advise diagnosing the loss of coolant and the overheating shutdown?

Thanks in advance.

Ok so the oil temp should be 250 or less and on average ~238 give or take 10.

Even though your oil temp was 250 at the time of the red overheat sign it doesn't mean your coolant temp (which is different) wasn't above the threshold.

Coolant (water temp) is not visible on the dashboard, you'd need to read it through a scan tool or other diagnostic tool.

How many miles are on the vehicle and current water pump?

[slay2k]

Originally Posted by Jeff@TopGearSolutions

Ok so the oil temp should be 250 or less and on average ~238 give or take 10.

Even though your oil temp was 250 at the time of the red overheat sign it doesn't mean your coolant temp (which is different) wasn't above the threshold.

Coolant (water temp) is not visible on the dashboard, you'd need to read it through a scan tool or other diagnostic tool.

How many miles are on the vehicle and current water pump?

83k miles (I bought it at 76k) and I have no paperwork regarding when/if the water pump was replaced. Is it possible for a water pump to cause such slow leakage and if so, would there be other evidence somewhere?

[Miller335]

Originally Posted by slay2k

83k miles (I bought it at 76k) and I have no paperwork regarding when/if the water pump was replaced. Is it possible for a water pump to cause such slow leakage and if so, would there be other evidence somewhere?

These cars eat a little bit of coolant, it is possible that someone wasnt keeping up on the small top off here and there and it reached the low coolant level warning.

Water pump going out is pretty common so that coming up now could be seperate from the coolant top off. The WP can crack though and cause coolant to slowly leak. GL

[slay2k]

So I just used the Carly app and it included the following codes (there were a few others related to, I believe, me disconnecting the battery in the past):

Fault: electric coolant pump, shut down
Code: 2E82
Fault: electric coolant pump, speed deviation
Code: 2E81

Pump on the way out? If so, how long do I have based on my symptoms? Or can you get these codes w/out having a faulty pump?

[AndyW]

Originally Posted by slay2k

So I just used the Carly app and it included the following codes (there were a few others related to, I believe, me disconnecting the battery in the past):

Fault: electric coolant pump, shut down
Code: 2E82
Fault: electric coolant pump, speed deviation
Code: 2E81

Pump on the way out? If so, how long do I have based on my symptoms? Or can you get these codes w/out having a faulty pump?

BMW water pumps are notorious for failing in the 75-100K range. Mine failed around 80K. If I had been smarter I would have preemptively replaced between 60-75K and avoided a minor crisis. I would replace your water pump AND thermostat now to pre-empt the complete failure(they are connected together and in the same spot and it's costlier than you think to have them replaced - it is a PITA to do - check out some of thE DIY's...but i digress)

[slay2k]

Originally Posted by AndyW

BMW water pumps are notorious for failing in the 75-100K range. Mine failed around 80K. If I had been smarter I would have preemptively replaced between 60-75K and avoided a minor crisis. I would replace your water pump AND thermostat now to pre-empt the complete failure(they are connected together and in the same spot and it's costlier than you think to have them replaced - it is a PITA to do - check out some of thE DIY's...but i digress)

Yeah, I'm taking it pretty seriously and getting a rental car to spare myself a 1hr commute each way tomorrow. Then I'll have about a week to sort it all out. I just want to be as certain as possible that the pump & t-stat need replacement before dropping all that money.

Mostly because I'm currently not getting the standard symptoms (yellow to red lights, can't drive car). The car is driving fine and only took a dump in 100 degree weather (and drove fine afterwards for hours).

[HooDat]

There's a plastic hose right behind the intercooler and under the radiator. I saw that my coolant was always dropping low and when I recently replaced my FMIC I saw that that hose was cracked. I electrical taped it up for a quick fix but will replace the hose soon. You may be having the same problem!!

[Jeff@TopGearSolutions]

Originally Posted by slay2k

So I just used the Carly app and it included the following codes (there were a few others related to, I believe, me disconnecting the battery in the past):

Fault: electric coolant pump, shut down
Code: 2E82
Fault: electric coolant pump, speed deviation
Code: 2E81

Pump on the way out? If so, how long do I have based on my symptoms? Or can you get these codes w/out having a faulty pump?

Definitely replace ASAP. Could fail tomorrow.

[AndyW]

Originally Posted by slay2k

Yeah, I'm taking it pretty seriously and getting a rental car to spare myself a 1hr commute each way tomorrow. Then I'll have about a week to sort it all out. I just want to be as certain as possible that the pump & t-stat need replacement before dropping all that money.

Mostly because I'm currently not getting the standard symptoms (yellow to red lights, can't drive car). The car is driving fine and only took a dump in 100 degree weather (and drove fine afterwards for hours).

I would consider changing your maintenance philosophy a bit...some stuff is "wait until it breaks", others, if you have a statistical basis for the range of miles it will probably fail, it is best to "chose the time and place of battle" with that part replacement, if you get what i mean. Pre-emptive replacement, especially since you have already had an indicator of pending failure, would be prudent here IMO.

[Antetokounmpo]

Ugghhh unless you want to be stranded replace ASAP. It will fail within a matter of days.

[MadeInPhilly]

lift your front end up and check the your waterpump. It is probably leaking coolant. Inspect all hoses to thermostat and waterpump. The pumps also do leak slowly through the casing as well. Check my thread.

http://www.e90post.com/forums/showthread.php?t=1148695

[Spacecpe]

Yes .. Your water pump probably has a hairline crack just like mine .. Started leaking coolant at first and in a matter of a week it failed without any signs! No codes! I was just about to leave my place and the fan went ham just by itself, so i knew at that point that the water pump just took a dump.. pretty simple Diy if you're handy.

[slay2k]

Alright, parts ordered (from importec) and will do the pump & t-stat replacement early next week =)

Thanks for the help fellas.