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URGENT - Fearing the worst, car just started acclerating itself to the redline, now abandoned on layby

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For the past week or two, my ABS light, brakelight and traction control light have been coming on every so often, leaving the driving like it was almost in limp mode.

Anyway just left the house an hour ago and as I got half a mile down the road, the car started accelerating, as I dipped the clutch it hit the redline. I turned the car of, freewheeled for a while, started the car again and it hit the redline.

Car is now awaiting towing.

Has the engine just blew?

cheers

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First thought is that it sounds like it is eating its own engine oil as fuel but if this was the case you wouldn't have been able to turn the engine off until it ran out of oil.

Don't know what controls the fuel on a diesel as it is not like a petrol.

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First thought is that it sounds like it is eating its own engine oil as fuel but if this was the case you wouldn't have been able to turn the engine off until it ran out of oil.

Don't know what controls the fuel on a diesel as it is not like a petrol.

I was about to suggest a diesel engine run away as well, but you're right, it would just keep running until it either ran out, burned out or you managed to stall it.

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So what you chaps reckon.

I gave the EGR a good clean out last year, have done 15k in it since. I will take it of and give it a good clean. I know the EGR cooler is pretty blocked but hard to clean.

Charge air pressure control - Anyone know what this is?

cheers

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As above, the engine would have destroyed itself if had ingested a flap at high RPM.

Does very much sound like oil, usually from a bust turbo seal. Perhaps pull the intake pipes off to double check if there is any sign of a leak anyway, just to be safe.

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Of course I will have a nosy and see, cheers for the advice!

What about this?

http://workshop-manuals.com/bmw/3_series_e46/320d_m47_tour/2_repair_instructions/13__fuel_system_%28m47%29/62__sensor_for_control_unit/3_ra__replacing_charge-air_pressure_sensor_%28m47%29/

Its matching one of my errors, 65 -charge air pressure control?

cheers

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If the cam sensor was gone though, surely I would expect the car not to start.

It starts perfectly and once I drive it, it starts the uncontrollable revving.

I am still no further forward with this guys, Ive took the inlet manifold of and as expect the car is FULL of carbon.

Other than that, im not so sure.

I have a 320d engine for parts here, from a rover 75.

So what does everyone think?

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Sounds to me like the throttle butterflies are stuck in the open position. When you turn off the ignition you disable the diesel fuel pump, starving the engine (which is why it stops, whereas with diesel runaway it simply wouldn't).

I had a similar situation in my old TVR when a piston disintegrated and a part of the debris managed to get out through the intake valves and wedged the throttle butterfly open (absolutely terrifying finding yourself doing double the speed limit in 30mph traffic, slaloming in between cars and wagons to avoid hitting them). Thing is though, with that situation the high rpm coupled with a compromised piston and imbalanced crank as a result pretty quickly saw a catastrophic mechanical failure (conrod through side of block, exploding engine, etc.).

Are the E46s a fly-by-wire throttle or is there a physical accelerator cable? If fly-by-wire throttle then I'm more inclined to think yours is an electrical problem too, or possibly some part of the throttle butterfly assembly breaking/sticking open.

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