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      08-31-2008, 06:47 PM   #20
Palbay
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Drives: 2007 BMW X3
Join Date: Oct 2007
Location: Upstate,SC

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Quote:
Originally Posted by Suzie's Dad View Post
But isn't that bit just in front of the windshield a high-pressure area? That's why they put the air intakes there for the passenger compartment. Which means that at speed air would be forced IN through those vents, even though it would rise out at rest.

If there is, indeed, a heat problem, I'm guessing it is from the catalysts and not the turbos. The turbos are cooled both by oil and by coolant, and they have a supplemental pump that keeps them cooling after engine shutdown. But the catalysts -- also right there at the back of the V at the top of the engine -- have no cooling at all. In fact quite the opposite: they need to have their contents almost red hot in order to work correctly.
I hope there is not a problem....and I'm a huge fan of turbo's.It gives us the horsepower we all love and helps w/ the MPG issue.Turbos are the future of high performance auto's.I'll tell you a story about my experience w/ Turbo engines.I owned a recent Audi A4 Avant w/ the "10 Time" or something close to that,"International Engine of the Year"......the 2.0L 200hp Turbo engine found in the Audi/VW lineup.It was the first engine to produce 100hp per/liter.It's been surpassed now by other engines.A state of the art powerplant.It had a feature found on many current generation turbo's...the ability to move engine coolant around the Turbo AFTER engine shutdown.I live very close to some great enthusiast roads in the mountains of NC,TN and North GA.I use them as much as time allows.I took the Audi up in the mountains on more than one occasion to TRY and make the electric circulation motor and pump that is suppose to cool the turbo upon shutdown engage after spirited driving.This was sustained redline driving,heavy engine braking,the whole nine yards.Not once after finding a place to pull over and shut the engine down,did I ever hear the electric pump come on.Maybe I never hit the "bingo" temp number to engage the pump...but the car was being driven very hard.I suspect the "pump on" temp number must be set so high by the auto manuf.....that it damn near needs to be an engine fire before the pump kicks in.My point is: these cars have all this gee wizz stuff to protect us and the car....But my natural distrust of modern engine electronics and some engineering,leads me to wonder if it really works like it was designed to operate.I know the Audi engine had very high oil and turbo temps just by the way I was driving the car.Just wondering in these high horsepower turbo engines if the underhood temps are really completely thought out and understood w/ the best intentions of the engine at heart.PS...Not meaning to scare anyone,but BMW took liberties w/ the 3 Series Coupe I think w/ the TTI6,and originally did not include an oil cooler in the car unless it came w/ the Sport Package.I think BMW went back and retrofitted non Sport Package cars w/ oil coolers.Just an FYI. Thanks! PalBay
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