[AGuyNamedGore_335i]

hey guys i just got a engine coolant light on my car but when im thinking of doing is just getting it flushed and using waterless coolant most prob Evans NPG waterless coolant and thoughts ideas or tips?

[jwalker87]

Any reason you want to go waterless? I've never heard of anyone having issues caused by OEM coolant, and that's what I'd recommend. I've flushed the coolant in both of my cars and used 50/50 mixture of OEM BMW coolant and distilled water both times. Like new! ECS Tuning has some decent prices IIRC.

[olivojoe]

Anybody ever come across a good DIY for an xDrive coolant flush for the E90?

I remember watching one, and the guy in the video said a few things would be different if you have the xDrive. I've never done a coolant flush myself so I'd like to watch a good thorough DIY before I tackle it.

[jwalker87]

Originally Posted by olivojoe

Anybody ever come across a good DIY for an xDrive coolant flush for the E90?

I remember watching one, and the guy in the video said a few things would be different if you have the xDrive. I've never done a coolant flush myself so I'd like to watch a good thorough DIY before I tackle it.

Other than the subframe placement making everything in the vicinity a PITA, there was nothing remarkably different between my wife's xdrive and my non. I can't remember if this is the fully approved procedure or not, but I drained the system by disconnecting the hose going to the water pump, filled with distilled water, let the car do its self-burping-water-pump procedure, then drained and repeated this whole sequence until the coolant was relatively clear.

[LaserPower]

You don't have to take the hose off. Take the front skid plate off and you should see at the bottom of the radiator, there is a blue drain plug. Take the plug out (there are 2 parts, the blue plug it self and the white housing. screw the blue plug out but hold the white housing in place. if not too much torque will damage the white housing as it is plastic and is designed to stay in there permanently once installed. There is a high chance of breaking the locking tab on the white housing even if you apply too much torque just to the blue plug), take the reservoir cap off and drain the system from there. If you managed to damage the plug (white housing more than likely), pay attention to your transmission type as manual uses a shorter plug than auto (auto utilizes a section of the lower portion of the radiator to cool the transmission. Manual does not need that so have a larger cooling area). (How do I know? Cuz I broke one...) In terms of coolant replacement, I don't think the xdrive is more work to replace than rwd. Water pump OTOH, is a very different story.

[olivojoe]

Originally Posted by LaserPower

You don't have to take the hose off. Take the front skid plate off and you should see at the bottom of the radiator, there is a blue drain plug. Take the plug out (there are 2 parts, the blue plug it self and the white housing. screw the blue plug out but hold the white housing in place. if not too much torque will damage the white housing as it is plastic and is designed to stay in there permanently once installed. There is a high chance of breaking the locking tab on the white housing even if you apply too much torque just to the blue plug), take the reservoir cap off and drain the system from there. If you managed to damage the plug (white housing more than likely), pay attention to your transmission type as manual uses a shorter plug than auto (auto utilizes a section of the lower portion of the radiator to cool the transmission. Manual does not need that so have a larger cooling area). (How do I know? Cuz I broke one...) In terms of coolant replacement, I don't think the xdrive is more work to replace than rwd. Water pump OTOH, is a very different story.

It is my understanding though that only draining from the plug on the radiator itself only flushes what is in the radiator, and does not remove any of the coolant downline in the engine. Is disconnecting the water pump the main way of doing this? Maybe that is why the guy in the video said there would be a difference between the RWD and xDrive models.

I have also seen kits in the past where you can leave the drain plug on the radiator unplugged, hook up a garden hose, and run the engine with hose water running through the system until it comes out clean (I think that is how it works.) Is this not a good practice?

[LaserPower]

Originally Posted by olivojoe

It is my understanding though that only draining from the plug on the radiator itself only flushes what is in the radiator, and does not remove any of the coolant downline in the engine. Is disconnecting the water pump the main way of doing this? Maybe that is why the guy in the video said there would be a difference between the RWD and xDrive models.

I have also seen kits in the past where you can leave the drain plug on the radiator unplugged, hook up a garden hose, and run the engine with hose water running through the system until it comes out clean (I think that is how it works.) Is this not a good practice?

That drains from radiator to the tank, which is the majority of all the coolant in the system. I don't feel there is a huge need to drain past the water pump, especially for xdrive considering the amount of work involved. As you mentioned about flushing the system, same as draining past the water pump, I would suggest unless the coolant drained out shows any kind of contamination that requires attention, don't waste time on doing a flush. The cooling system is mostly a closed system and not likely to be horribly contaminated (not saying it's impossible, just not very likely if everything is up to the manufacturer's standard. My previous 2006 330 xdrive has more than 120000 km on the odometer and the coolant I drained out was mostly like new when I replaced the pump on that one. ).