[Frank_NJ]

Knowing BMW rock solid! My 1973 Turbo 2002 is an excellent example of BMW turbocharging that works and is reliable.

[James Bond]

Sorry, but BMW unfortunately had have often problems with turbo-chargers, mainly in E46 with 4-cylinder-diesel-engines.
And very often the drivers couldn´t do anything against this, they drove the machine from start more softer before pushing it into higher revolution speed.
The chargers make in this case a very high fizzling-noise while driving,
this was the first indices for a damage charger - I hope, BMW will be
learn from this situation and avoid this for the future.

[Jason]

I've combined the "How reliable do you think the turbo will be" with this thread since the discussions were similar.

[qroc]

Originally Posted by SteVTEC

It is a challenge. There is significantly higher mean effective pressure in the engine that the cylinders all have to deal with. There is also significantly higher heat both going into the engine and in the engine bay itself, so you need a robust cooling system. You need a sturdy engine block also that will not fatigue or warp, same with the heads. The turbos themselves are quite challenging because they're subject to constant acceleration and deceleration to and from 100,000 rpm or more, and handle the extremely high exhaust gas temperatures of petrol engines which can exceed 1000C. And they're expected to be reliable for the life of the car. The entire engine needs retuning as well both for performance and emissions because NA engines need different things than FI engines. The powerband needs to be smooth so that means minimal lag and zero boost surges or other unexpected phenomena. There are detonation issues to worry about also.

There are plenty of historical examples out there of what can go wrong with poorly designed turbocharged engines. Audi has a lot of recent ones. Oil gelling and huge coil pack issues on their 1.8T engines, and the 2.7TT V6 engines had poor thermal management which results in a lot of turbo failures. Even Toyota 2JZ-GTE engines from the Supra TT were known for secondary turbo failure on their sequential setup. The more complex you make an engine, the more difficult it is to bulletproof it. It's not easy by any means.

Coil packs don't necessarily have anything to do with turbocharging afaik.

Hehe, having owned and dealt with modifying heaviliy a 911 turbo I hear you. Its more complex than na cars but I don't consider it a particular challenge for BMW to do turbocharging right. There is industry data on this since the 70s yes?

But given how common turbo charged cars are nowadays, how old the technology is, how they are gaining popularity, and how tbh I can't think of any recent turbo cars which had spectactular design failures (I think of the reliability of Subaru's turbocharged cars in particular) I feel pretty good about BMWs ability to pull it off. The direct injection part is in my view a cause for concern if any, as well as how damn complicated the engine is (just read the Edmunds thing re: the water pump etc).

[SteVTEC]

those engines can sludge up and have problems even stock, though.

[gIzzE]

Originally Posted by Robin Hood

I agree, but a turbodiesel isn't a turbo petrol engine. It's like talking about a Swedish and a Danish girl, you think they're 'the same' but they're not

So you have a DMS 535d? 320BHP? Read some tests. Great drive.
I love turbodiesels in general. I used to own a E46 330d too.

Yeah I have a 535dms Touring, 340bhp and over 600nm of torque, which is a nice ride, a bit like our Swedish friends, also a nice ride!








I am seriously tempted with a 335i touring though, bet you would get near 400bhp out of that without too much trouble.

[Safety2213]

From my understanding, the 335i turbos are Mitsubishi turbos with very little boost at partial throttle. Mitsubishi has an excellent reputation for longevity. Regardless, like any mechanical part, I think changing the oil frequently 5K or 7.5K and coolant every 2 years should insure a trouble free life for a significant amount of time. I am not an engineer, however BMW has a long standing tradition of building in a HUGE amount of "room for error" and are conservative in their engineering. I was considering the 328i rather than the 335i b/c of the turbo's however really enjoyed driving the more powerful car.

Certainly, abusing any motor will cause problems. I have owned several first or second year model BMW's and have had very few major problems, the worst was a clutch part and a water pump. Anyway, enjoy your car and have fun!