

Chevrolet Volt  (Source: Brandon Hill, DailyTech)

Cadillac Provoq  (Source: Brandon Hill, DailyTech)

  (Source: Brandon Hill, DailyTech)
GM uses CES to display its highly computerized automobiles















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RE: Props to GM
By Spuke on 1/9/2008 12:14:16 PM , Rating: 2
LOL - i think i typed it wrong. I did not personally turbocharge my car.
It did read funny. What kind of problems were you having with the turbo? A turbo is a mechanical device and a simple one at that. I find it hard to believe that there would be many turbo failures.

RE: Props to GM
By mdogs444 on 1/9/2008 12:20:56 PM , Rating: 2
Well mine was an 02, and according to the Audi mechanics at my local dealership, most have to have the timing belt, fuel injectors, and many other parts replaced early (at 60k) due to the strain that the turbo puts on the motor. Im no mechanic, so it may be B.S - but the audi was the only turbo i've had, and in all: injectors blew at 55k, timing belt needed replaced at 60k, intake manifold needed replaced at 60k. Im sure i can pull up more receipts, but that car had more mechanical & electrical issues than any car i've ever seen. could've been a lemon though. But i prefer a basic motor that i can still work on a bit - as opposed to the new technology that even most mechanics can't fix.

RE: Props to GM


RE: Props to GM
By Moishe on 1/9/2008 2:37:04 PM , Rating: 2
Honestly, it's not the turbo, it's the Audi.
I was in the market for an Audi not that long ago and did a bunch of research. As nice as those cars are, they've had a real problem with reliability in the past few years.

RE: Props to GM
By Spuke on 1/9/2008 2:41:34 PM , Rating: 2
You might see some stresses to the internal components but the timing belt and injectors? Timing belts are usually changed at 60k on any car. That's normal. The weird things are the intake manifold and the injectors. Intake manifolds don't go bad. It's just of hunk of metal to allow air into the engine. Unless they punched a hole in it when trying to fix something else.

Those mechanics fed you a line of crap. The car was designed to be boosted from the factory so Audi would take that into account when designing the motor.

BTW, I've heard other people complain about Audi's and VW's quality so these problems don't surprise me.

RE: Props to GM
By mdogs444 on 1/9/2008 4:40:14 PM , Rating: 2

Only wish I had known that years ago. The electrical system was a nightmare. The external temperature sensor was linked to the interior digital temperature control. The external sensor always blew, so when it did, this is what would happen (as an example):

Its 90 degrees outside. Temperature sensor went bad, and read -40 degrees. Put A/C on, but blows in 90 degree air - since the computer thinks its can use the cold air from outside instead.

From what I understand and read on multiple Audi forums, this is a common issue. So is engine sludge, early timing belt breakage around 60k miles (when recommended per manual is 90k), window motors breaking (mine did, and bumped window off track & shattered inside the door panel). The list goes on. It really turned me off to this idea of "german luxury" engineering.

RE: Props to GM
By MrX8503 on 1/9/2008 2:57:20 PM , Rating: 2
Turbos are forced induction. Forced being the keyword here. Theoretically a turbo charged engine would be less reliable than a non-turbo charged one. Unless the cylinder walls are thick enough, a turbo charged engine would be less reliable by nature of forcing more pressure into the engine to create more horsepower.

On another note, diesel engines would theoretically be less reliable than gas engines because diesel uses high pressures to ignite the gas/air mixture, whereas gas engines uses a spark plug. Pressure ignition is a lot more efficient because it ignites every molecule resulting in better mileage, but it puts an incredible strain on the engine from high pressures.

RE: Props to GM
By masher2 (blog) on 1/9/2008 4:40:05 PM , Rating: 2
> "diesel engines would theoretically be less reliable than gas engines because diesel uses high pressures "

True. In practice, however, diesel engines are nearly always more reliable, because they're built to withstand those higher pressures.

> "Pressure ignition is a lot more efficient because it ignites every molecule... "

No. A diesel engine is more efficient because it runs off a higher temperature differential. The efficiency of a heat engine is based on the difference between its high and low temperatures.

RE: Props to GM
By theapparition on 1/10/2008 8:47:16 AM , Rating: 2
So wrong I don't even know where to begin.

Forced inductions (Turbo/Superchargers) are certainly more harsh on engines, and the cylinders have to cope with much higher pressures. However, no engine I've ever seen has had a direct cylinder wall failure from pressure. You'll usually get piston/rod or head/valve problems before every having to worry about cylinder integrity. In fact, usually the only reason a cylinder wall gets damaged is from failure of the other components (like a snapped valve being thrown around the clyinder at 6500RPM), or from very high heat, which forced inductions are prone to. There are ways to combat heat, like both my SC cars have meth injection.

Turbo's are far less reliable because they use exhaust pressure (very high heat) to spool a turbine. Those turbines spin at very high speeds to make any appreciable boost. ANYTIME you spin something faster, it is prone to wear out sooner. That's a core tenent of mechanical engineering. Bearings wear out faster, material fatigues quicker, etc. Add the high heat were dealing with and that only accelerates this effect. Plus, oil can cook in the turbos if driven too hard.

Many reasons that turbos are far less reliable than NA engines, but cyliner wall integrity is not one of them.

