Question on engine coolant maintenance schedule: 125k miles

[hendeerd]

Hello all. Just purchased a 2014 REX with 125k miles.
I am thinking the REX coolant is due for a change. I can not find and schedule for this or any procedures.
Can someone help me out here?

I am thinking that all coolant loops should be changed since the car is approaching 10 years old.

I do all my own maintenance and would like to do this on my own.

Cheers.

 

[hendeerd]

I found that the BMW the blue coolant should be good for 150000 miles or 5 years.
From this I am overdue for a change on calendar life.

Anyone out there have the procedure for the coolant change?

David

 

[jreynaert]

There are actually two coolants, one which keeps the battery cool and the other which is for the Heater system.
FCP Euro sells both, and the one for the battery appears to be BMW Part# 83512355296
Mix 50/50 with distilled water. I haven't yet seen any posts on the procedure to flush, just the one YouTube on changing the coolant pump.

I'm also trying to determine the which ones are used under the frunk. I would assume that the black cap one in the rear is for the Battery Coolant.

I'm creating a maintenance log for my 2014 i3 (Non-Rex) see attached. I actually have this in Excel.

 

[alohart]

There are actually two coolants, one which keeps the battery cool and the other which is for the Heater system.

The HV battery pack is cooled by the refrigerant in the heat pump or A/C system, not by coolant. However, the propulsion motor and the motor electronics (EME) are cooled by the coolant not used by the cabin heater.

 

[jreynaert]

Good to know!
Do you know which coolant goes it the "black" container? Heater Circuit? I would assume BMW 83512355296.
As the other white container in front appears to be for regular coolant, like BMW 82141467704.

Does anyone know where instructions for flushing can be found, for both types? As well as capacity of each.

 

[Redryder18]

The HV battery pack is cooled by the refrigerant in the heat pump or A/C system, not by coolant. However, the propulsion motor and the motor electronics (EME) are cooled by the coolant not used by the cabin heater.

Back in the day, A Haynes manual was the be all & end all for working on cars. Is that still true? And do they make one for I3? If not, which one is a good DIY book

 

[alohart]

Back in the day, A Haynes manual was the be all & end all for working on cars. Is that still true? And do they make one for I3? If not, which one is a good DIY book

Haynes doesn't appear to sell an i3 manual. I've never found a workshop manual for an i3. The best PDF manuals I've found are BMW's Technical Training manuals.

 

[macdaddybighorn]

If you have a computer and quite a bit of hard drive space you can download ISTA and it should give you all the instructions. It's a free download if you search around. You will need an ENET OBD2 cable, though. It's what the BMW techs use to diagnose and repair the cars.

 

[jreynaert]

The Heating System Circuit, Black Tank, takes BMW Part#: 83512355296

The Coolant Drive Circuit, White Tank, takes BMW Part#: 82141467704

Mix both 50/50 with distilled water. I get my BMW parts at FCP Euro, due to their lifetime warranty (even on wear out items).

 

[TheAirman]

Good to know!
Do you know which coolant goes it the "black" container? Heater Circuit? I would assume BMW 83512355296.
As the other white container in front appears to be for regular coolant, like BMW 82141467704.

Does anyone know where instructions for flushing can be found, for both types? As well as capacity of each.

The black container is the expansion tank for the REX cooling system. I think it has to be refilled and bleed using a vacuum system.

The white tank is the expansion tank for the electric motor. It's draining and refilling is deep. It also needs a vacuum refill procedure.

To me, it doesn't look like a home mechanic job because of the special tools. Ask the dealer. I'll try to get the documents on the procedures later.

 

[jreynaert]

My 2014 is not a REX, and has two containers.

Maybe good easiest to just swap out the fluid in the containers every couple years, when bleeding the brakes.

 

[alohart]

If you have a computer and quite a bit of hard drive space you can download ISTA and it should give you all the instructions. It's a free download if you search around. You will need an ENET OBD2 cable, though. It's what the BMW techs use to diagnose and repair the cars.

I've done just that with ISTA 4.39.20. ISTA is able to read the VIN of our i3, so the OBD to Ethernet cable is working at least partially, but ISTA is unable to do anything else for reasons that I haven't been able to figure out. It is also unable to do anything after I enter the VIN manually.

ISTA isn't particularly user-friendly for those who aren't authorized to use it.

 

[hadaR1150R]

Just joined. Have 2017 Rex I bought new (Long Island NY). Pretty good luck so far but well past warranty now and looking to understand maintenance needs. My dealer was OK but is now out of business. Somewhat terrified of what new dealer would charge, for example, to replace the 7+ year old 12-V battery, which I can see from forums would be a good idea to do proactively. Trying to pump myself up to do it myself but concerned about generating a bunch of faults I don't know how to handle. Have just ordered the plug-in widget so I can use BimmerCode and BimmerLink.

Previous cars I've owned have had explicit manufacturer-recommended service schedules in the owner's manual. The i3 should need less maintenance, but not nothing, which is what's in the manual! I have found a lot of info on this forum, thanks to you all, but still have some questions.

1. The Rex coolant: what are the recommendations for when it should be flushed and replaced? Should I be watching the hours/miles run time of the Rex (relatively low)?

2. Rex air filter: how often should it be checked for possible replacement? Based on hours of Rex operation?

3. Rex spark plugs: when should they be replaced based on hours of Rex operation?

4. Transmission fluid - not sure it should be called a transmission, but has gears and gear oil. Should the oil be changed every 40K miles, or what?

5. The electric motor coolant - for other EVs, I see it is expected to have a very long lifetime, 8 or 10 years or more. But is there a recommended time to replace?

6. Anyone know a good shop in Nassau County NY (or eastern Queens) where they actually have useful experience working on i3s?

Some concerning behavior lately that appears to be resolving, theory still holding that I let gas in tank get too old (even tho ethanol-free and with Stabil). Started the stupid procedure of burning the gas by letting battery discharge to 6%, but Rex would only run about 10 minutes and then shut down with a clueless error message, leaving me to limp home on almost no charge. Let Rex cool down, and it would run again for about 10 minutes. Thought maybe it was overheating. Checked Rex coolant, and it was not low. Check engine light came on. Onboard info says that may have to do with "deteriorating emissions." So again, maybe the old gas triggering emissions sensor and causing Rex shutdown? (I had topped off about 1/3 tank with fresh gas.)

Discovered here the emissions inspection mode. Good to know. First time, it shut down after 10 minutes. Second, same. Third time, hallelujah! It ran the full 20 minutes, and the check engine light went dark! So now I'm optimistic that if I finish getting the old gas out (concentration of new gas may be improving as I go) this issue will be fixed. (Dealer told me there was no way to drain the gas tank. Insanity!)

Of course I will use BimmerCode to allow me to run the Rex while I have some battery charge to work with. Still need to demonstrate that the Rex will run for an extended period without shutting down and throwing a mystery error. Maybe if it does I can see in BimmerLink what the actual fault is.

Anybody have similar experience? Do you know why the Rex shuts down after 10 minutes? Old gas the culprit? Something else?

I really like the car. Let's all work together to keep them on the road and avoid crazy repair/maintenance fees!

 

[jfran2]

Using Bimmerlink to code Hold State Of Charge will make your life much easier, and the car more useful (IMHO). Once the charge is down to 75% or below you'll be able to activate HSOC while you still have plenty of charge left in the battery. Once you build up some confidence in it, I'd recommend taking it out for a trip every couple of months to give it some exercise and change out the gas. One more thing - these cars have a pressurized gas tank, so products like Stabil should be unnecessary. That's why you have to push the little button below the dash before you fill up - that vents any built-up pressure.

John Francis
Rolla, MO

 

[hadaR1150R]

Using Bimmerlink to code Hold State Of Charge will make your life much easier, and the car more useful (IMHO). Once the charge is down to 75% or below you'll be able to activate HSOC while you still have plenty of charge left in the battery. Once you build up some confidence in it, I'd recommend taking it out for a trip every couple of months to give it some exercise and change out the gas. One more thing - these cars have a pressurized gas tank, so products like Stabil should be unnecessary. That's why you have to push the little button below the dash before you fill up - that vents any built-up pressure.

John Francis
Rolla, MO

Thanks John, good points. I actually received my plug-in gizmo yesterday and used BimmerCode to change code to allow Hold State of Charge. I'm getting the old gas out gradually... can't do it fast because the Rex motor will only run between 10 and 20 minutes before it shuts down. It acts like something is overheating, because if I park it for 2 or 3 hours the Rex will run again. And one of the historical error codes BimmerLink lists multiple times is
21DDD0: REME Inverter, power-reduced operation: temperature threshold exceeded
REME is for range extender electrical machine electronics
Not sure why the REME would get hot. I don't appear to be low on the coolant for the electric motor.
I see in documents found via this site that the REME is cooled by the same coolant circuit that keeps the electric motor cool.
One thought I have is that maybe the pump for that coolant is not working well. But I don't see any errors/faults related to the main electric motor getting hot.
Another thought, the sensor that is saying the REME is too hot might be defective.
On the other hand, the 21DDD0 error is not showing in current errors, just a collection of them in the past (BimmerLink doesn't pinpoint the km figure for those old errors).
Also seeing that the Rex coolant doesn't have its own separate radiator. It has heat exchanger that passes engine heat to the coolant used for the electrical systems before that coolant goes through the radiator. So if my radiator is full of crud or the radiator fan isn't working... could be a lot of things.
One of the CURRENT errors BimmerLink reports is:
CD8C2A: Deactivation of the combustion engine due to an internal error
Anyone know where I could look for info about my error codes? Like what kind of internal error, for example.
Jeremy

 

[TedStriker]

If you have a computer and quite a bit of hard drive space you can download ISTA and it should give you all the instructions. It's a free download if you search around. You will need an ENET OBD2 cable, though. It's what the BMW techs use to diagnose and repair the cars.

Just a bit of info here, you don't need any cable to use large parts of ISTA, only if you need to read codes or run procedures. The workshop manuals are accessible without any connection.

 

[Labas Rytas]

The black container is the expansion tank for the REX cooling system. I think it has to be refilled and bleed using a vacuum system.

The white tank is the expansion tank for the electric motor. It's draining and refilling is deep. It also needs a vacuum refill procedure.

To me, it doesn't look like a home mechanic job because of the special tools. Ask the dealer. I'll try to get the documents on the procedures later.

i have black container also, but not rex engine, so you not right tho

 

[alohart]

i have black container also, but not rex engine, so you not right tho

The REx engine has its own coolant circuit and reservoir in the rear of a REx. A heat exchanger transfers heat from this coolant to the coolant in the motor and motor electronics coolant circuit whose reservoir is in the frunk. A REx and a BEV both have the same coolant reservoirs in the frunk, one for the cabin heater circuit and the other for the motor and motor electronics coolant circuit.