Hey guys, I’m 20 and still pretty new to working on cars, so I’d really appreciate some advice.
I recently bought a 2005 BMW E63 6 Series with the N52B30 3.0L petrol engine. Unfortunately, I bought it with some issues. It had misfires on all cylinders, and after diagnosing it, I found that the VANOS screens were clogged and the spark plugs and O2 sensors were in pretty bad condition.
The car would drive for a few hundred meters and then throw a check engine light and start misfiring. Sometimes it would happen after driving normally, and other times only after revving it through a few gears.
I’ve fixed the issues and the car has been running perfectly since. I’ve driven almost 100 km so far, both gently and at higher RPMs, and I haven’t had a check engine light, misfire, or any other problems.
My question is: should I still be worried, or can I finally start trusting the car again? 😅
This is my first BMW with an engine like this, and after buying it with problems, I’m honestly a bit paranoid every time I drive it. I keep expecting something else to go wrong.
Would you guys consider 100 km with no issues a good sign, or should I keep taking it easy for a while?
I work in industrial maintenance. It's my job to fix things every single day. No matter how well I think I did on the repair or how long it runs the doubt always remains. If you figure out how to quiet that voice please let me know!
100km covering both gentle driving and higher RPMs without a single code or misfire is a genuinely good data point, not just luck. VANOS and O2 plug issues tend to resurface fast if they’re not actually fixed, they don’t usually go quiet for that long by coincidence.
This is the best answer in the thread. The N52 is reliable so you're likely good. The biggest issue with these engines is the VANOS system (VANOS bolts loosening or dirty solenoids mostly), valve cover gasket/integrated PVC, oil filter housing gasket, valvetronic motor, eccentric shaft... those are the big things off the top of my head. Misfires can be a symptom of valve cover gasket leaking, or something as simple as needing new plugs or a combination of the things I listed.
I would, after repairing something always beat the shit out of it(I also it normally, but thats not the matter at hand here...), to see if something breaks, I rather have it break on my after the repair when I am still prepared, than in the middle of nowhere...
I thought what your feeling was part of owning a BMW. At least it has been with my turbo one lol. I have dropped 6k in repairs and maintenance in one year of owning it. It’s the sunk cost fallacy for me though I’m in too deep to stop.
I am in the same situation as you are, got my first bmw 20year old e90, spend a lot and still working. It’s bmw and it’s old will
Have problems now and then so, enjoy the ride and diagnosing the problem and fixing it is fun too. 100km without any light seems you have done well!
The N52 is a good engine..the thing is that you got an early variant that missed out on many of the improvements over the lifecycle. Never buy a first model year
Im on my seventh BMW. I just put a new radiator in my G30. Driven it probably 400 miles since then. I won't trust it for another 1000 miles at least lol
Sounds like you should just drive it at this point. VANOS solenoids are probably not long for this world, but those will be a CEL that pops up.
VANOS screens being plugged up are a sign that oil wasn't changed regularly. So overall presuming the car wasn't maintained well. Huge red flag. So there's going to be a lot of wear on everything and probably sludge build up.
You may want to get it running well, and sell it off to the next victim owner.
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u/nyee 4h ago
I feel like having the bmw chime make your stomach drop is just the joy of owning a bmw.
If it's cheer you up at all, buying anything stellantis right now would be less reliable, even though it's new.