BMW E90 Radiator Replacement Time – 2 Hours
A BMW E90 radiator replacement is one of those repairs that can come out of nowhere. This is due to the fact that many of the radiator parts are plastic and are prone to cracking when put under abnormal stress; like a front end impact to the vehicle, age, or other engine repair work that may have caused incidental damage.
You wouldn’t think we would be have to change the radiator out of a seven year old E90 335i, but for whatever reason listed above, we found our donor car seeping fluid out of the drivers side plastic fitting where the upper radiator hose is mounted. Further investigation showed that someone at sometime had tried to work on a part in that general area…we could tell by the missing and mismatched screws. Our guess is someone put to much pressure on the upper radiator hose causing a hairline fracture in the radiator. It was enough of a fracture to cause the “low level” coolant light to display every couple days; a very dangerous situation that needs to be fixed immediately.
The good news is a BMW E90 radiator replacement is really not that difficult, and best of all there are a bevy of aftermarket parts at much lower prices than the original unit. We saved close to $1000 on parts and labor from compared to what the dealership quoted us; that’s a lot of unnecessary expenditure in our opinion.
***Before starting the BMW E90 radiator replacement, you will need to remove your vehicles electric cooling fan that is mounted in front of the radiator. Please read our article on BMW E90 cooling fan replacement by clicking here.
T25 torx T Handle or T25 3/8″ socket and ratchet
8mm nut driver or 8mm 1/4″ socket and ratchet
Flat blade screwdriver
Phillips head screwdriver
5 gallon drain pan
Parts and Supplies
BMW E90 radiator
Schwaben Radiator coolant refill/air purge tool (This is the tool we use at the BMW Repaire Guide. It insures a perfect refill of your cooling system and can be used for other diagnostic repairs as well. We highly recommend using this tool instead of trying to refill manually.)
Genuine BMW Antifreeze/Coolant – 2 gallons (will make 4 gallons when mixed 50/50 with distilled water.
- You will need to jack and support your vehicle using the “four corner method” since you will need to get under the front of the vehicle. Please click here to learn how to properly jack and support your vehicle for this repair.
- Remove the coolant reservoir cap. The cap must be removed for the BMW E90 radiator to drain properly.
- If you are working on a twin turbo (335i), move to underneath the front of the vehicle to start removal of the turbo intercooler. The intercooler must be removed to access the radiator drain plug. If you are working on a non-turbo model (all models other than the 335i or M3), please skip this section and proceed to step 8 below.
- Remove the front protective plastic belly pan from the underside of your vehicle. It is held in place with 8mm screws.
- Unfasten the two clips holding the plastic protective shield to the bottom of the intercooler. They simply lift up and turn to release.
- Using a flat blade screwdriver, release the retaining clips on the two intercooler hoses.
- Remove the two T25 torx screws anchoring the intercooler to the vehicle. Grasp the intercooler and carefully remove from vehicle.
- Using a large flat blade screwdriver, unscrew and remove the radiator drain plug. Have a 5 gallon drain pan ready to catch the fluid. Let the radiator completely drain.
- After the BMW E90 radiator has drained, move back to engine compartment and remove the upper radiator hose by releasing its retaining clips and pulling loose from the oil filter housing and the upper radiator. Be VERY CAREFUL not to break the plastic fitting that connects the fluid reservoir overflow tube to the upper radiator hose. Gently push the hose back towards the firewall so is out of the way of the radiator (we tucked ours behind the oil filter housing with a towel – see image below).
- Working on the right side (passenger side) of radiator, release the retaining clips on the two lower radiator hoses and gently pry off of radiator. You may have to get back under car to reach one of the clips…every vehicle seems to be different.
- Working on the right side (drivers side) of the radiator, remove the oil cooler hose that is attached to the bottom of the radiator. The oil cooler hose is anchored to the radiator with a plastic mount that is secured with a T25 torx screw.
- Remove the two T25 torx screws anchoring the top of the radiator to the frame of the vehicle.
- Grasp top of radiator with two hands and remove from vehicle. Work slowly so you don’t snag any pipes or electrical connections. It usually helps to slightly tilt radiator towards rear of car when removing.
Preparing new radiator for installation
Your new radiator will need to be prepped prior to installation, since they are usually shipped without the drain plug assembly or the two plastic hose mounts installed.
- If a new drain plug assembly is included with your radiator proceed to step 3.
- If your new radiator did not ship with a new drain plug assembly, you will need to reuse the one from your old radiator. First, unscrew and remove the drain plug. Use a pick or a small flat blade screwdriver to GENTLY pry the drain plug sleeve out of the old radiator.
- Install the drain plug sleeve into the new radiator. Push firmly to make sure all of the o-rings are seated properly.
- Install drain plug and tighten (do not over tighten).
- Remove the right side plastic hose mount from the old radiator by removing the T25 torx screw and GENTLY prying out with a flat blade screwdriver. Reinstall in new radiator.
- You can now install your new radiator following the above steps in reverse. Make sure all of your hose connections “click” shut and are tight.
Refilling radiator with coolant
Only refill your BMW E90 radiator coolant system using Genuine BMW Antifreeze/Coolant mixed 50/50 with distilled water. We do not recommend using any other brand.
At the BMW Repair Guide, we only refill coolant systems using the Schwaben radiator coolant refill/air purge tool . We are currently working on instructions on how to properly use this tool…until then please refer to Schwaben’s YouTube video on how to operate.
If you have any questions or comments, please feel free to contact us. And congratulations for Doing It Yourself!
The Repair Difficulty Level displays graphically how challenging the repair is, from easy to advanced. Easy repairs usually require very few tools, have short repair times and do not require jacking and supporting the vehicle. As the difficulty level rises, expect the repair to demand more time, specialized tools, and better understanding of mechanics to complete the job.