Welcome to Tech Talk, where our resident BMW tech Nick Owen answers all your pressing BMW technical questions, frustrations, and issues. Have a question for Nick? Email him at techtalk@roundel.org. Let’s get into it.
N55 DISASTER PREVENTION
I own a 2018 M2 (F87) and love it. I keep my cars for ten years or more and am a big believer not only in regular “old school” maintenance but preemptively replacing parts that have higher failure rates.
I replaced the plastic charge pipe early on several years ago, and I am considering replacing the plastic “Mickey Mouse” flange (thermostat to cylinder-head hose) and adding a crank-seal guard. What are your thoughts regarding these? Can you recommend any other replacements that may help prevent costly repairs in the future
Mort Kahlenberg
Atlanta, Georgia
As one N55 M2 owner to another, I have found that these two failure items usually occur only when neglected. The Mickey Mouse ear flange does get soft over time due to its material; if you do ever remove it and it shows signs of being brittle, then it is very wise to replace it. I think by the time you are at the 75,000-mile mark, it should be considered for preventive replacement. However, I have seen them go for much more mileage (100,000-plus). Once they are removed, we discover the true integrity of the part.
Same with the serpentine belt: If there are signs of cracking or fraying on the edge of the belt, replace it. I will say that BMW belt life has improved considerably in the last fifteen years, but they can still fail by or before the 100,000-mile mark. Also, a failing idler pulley could cause the belt to fail and get sucked into the front crank seal, so I think the guard is a good idea for peace of mind. Maintaining the engine with a known good serpentine belt and healthy pulleys can prevent belt failure.
As for other replacements, I recommend a new water pump by 100,000 miles. I do not trust an electric water pump as far as a I can throw it, so I replaced the one in my wife’s M2 at around 65,000. But other than that, the N55 is solid and requires relatively low maintenance.
LOWERING A FIVER—OR NOT
I have a 2001 530i five-speed with sport package. I love this car and how it rides, but I would like to lower it, especially in the front—just a little bit to close the fender gap. The rear ride height is fine. Do you have a suggestion?
Also, my driver’s-door window regulator is making cracking or popping noises, and I am afraid it is about to go. Can you recommend an available replacement that is a high-quality part? I have been told that most of them will not last a month.
Rob Walshe
Morrisville, North Carolina
When it comes to lowering the car, you must do it in conjunction with both axles—you should not just lower the front a little, because that will induce more rake into the chassis geometry, and can make the car feel unstable. Also, the only way you are going to lower the car is to use an aftermarket spring kit, which comes as a set, front and rear. If you only want to lower it a little bit, then I would recommend an aftermarket OE replacement spring or one that will only lower it no more than half an inch. Most aftermarket “sport suspension” springs will lower the car over an inch in the front and half an inch in the rear. Also, changing the springs will change how the car rides; it may not be noticeable to some, but if you are pleased with the way the car drives and rides now, please understand that changing the springs and lowering the chassis will affect it.
As for the window regulator, there is no upgrade that I am aware of. If you buy it from BMW, then it comes with a two-year unlimited-mileage parts warranty whether they installed it or not. Hope this helps.
X3 SUNROOF WOES
On my 2018 X3 (G01), my sunroof “pops” when it is opened after it has not been opened for several days. When this occurs, the interior headliner associated with the sunroof often bunches up instead of retracting the several inches as it should. The popping is loud and smacks of a significant mechanical interference. It has been doing this for several months, and so far, nothing has broken, but I am worried. I did apply Gummipflege to the gaskets between the moveable glass panel and the larger glass panel that retracts farther back; I thought this might resolve the problem, and it did not re-occur for several days, but eventually the popping came back.
Dave Lenderking
Wilmington, New Jersey
Sunroof popping noises are never good—however, it is tough to determine what exactly is causing the popping without entirely removing the sunroof cassette. My concern is that at some point it is going to pop and stop moving, and you will not be able to close it, so please beware of this risk.
You will most likely need to take it to someone who is familiar enough with the sunroof cassette to diagnose the issue. While it may be possible to remove the retractable glass part, you still might not be able to see the defect with it still installed in the car. Assuming that you do get the cassette out of the car, it may be determined that the failed part is not serviceable, meaning that there is no separate replacement part, and you will have to replace the entire cassette, glass excluded. I just had this experience with an F13 6 Series, and the repair was $3,500 at the dealership—with discount. I recommend that you prepare for the worst-case scenario.
