100k+ Mile N54 Opinions

[pine1000]

I'm considering a 135i with 140k miles. Is this a recipe for disaster or are these engines fairly reliable at higher mileage?

I've done a lot of basic repair work on my S52 M Roadster and other cars (water pump, alternators, suspension bushings, hoses, etc...). Is the N54 a beast to work on with all of the turbo plumbing?

Thanks

[Cyrix2k]

The N54 isn't too bad to work on for most things, but beware the packaging is much tighter than your S52. There's more to go wrong (and it does go wrong) and it's harder to get to. The actual rotating assembly is solid in N54s but everything bolted to the block breaks. In terms of mileage, I haven't seen where high mileage is a large detriment to the N54. They just constantly have problems regardless of the mileage. Basically, they usually run (is that reliable? I don't know) but will need constant work to run well. And they *constantly* throw codes. It's non-stop. But for the short periods when they run well, they make power.

[Genes1s]

I have S52 E36 M3/4/5 and recently just acquired N55 135i DCT. I too was looking N54, but quickly realized that N55 has less parts to go wrong, granted that it is less friendly to extract power compared to N54, but it would still be much easier to get power than S52 for sure. For the most part, the engine compartment layout is similar but with less room to work on, more wires and sensors every where, but I think it still is DIY friendly. One thing is nice is that bleeding the coolant is very easy with this car since they have electric water pump.

I think the biggest different is the electrical diagnostic and trouble shooting. This 135i has way more electrical craps that makes me nervous. I think mechanically, they are a little bit more complicated than E36/46 but still pretty doable to DIY.

I have my 135 for just a day old and I can tell you that I still like my E36 M better. The 135i is a modern E30 with fancy stuff and super comfy. Steering is heavy, but less connected than the E36M. The chassis is sitffer than e36 i feel but the suspension is way softer and floaty. I love the look of the 135i though and with DCT, it more practical for DD.