possible turbo fault

hi all hippo has been to two garages now one didnt have a clue the other said possible turbo fault the symptoms are a metallic rattling sound (sounds like a machine gun) and loads of black smoke but only under load i e overtakeing ease off the go peddle no more noise and no smoke there are no fault codes any of you wise men got any ideas before i go to the expence of a turbo car has done 209000 miles so i suppose its possible many thanks

tincan said:

hi all hippo has been to two garages now one didnt have a clue the other said possible turbo fault the symptoms are a metallic rattling sound (sounds like a machine gun) and loads of black smoke but only under load i e overtakeing ease off the go peddle no more noise and no smoke there are no fault codes any of you wise men got any ideas before i go to the expence of a turbo car has done 209000 miles so i suppose its possible many thanks

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Hard to say. Only way I can think of to be sure, other than swapping out the turbo, is to get hold of a scan tool with either freeze frame data or live data display and monitor boost pressure while you go for a test drive.

The Td4 does make a sort of rattling sound under load - if you select too high a gear, for example. If your vacuum powered boost mechanism is failing (check it), then the engine could be inadequately powered and hence make that noise. Similarly, check intercooler hoses for leaks. All in the spirit of checking absolutley everything before you go to the hassle and expense of replacing the turbo.

thanks for the input all new silicon hoses so not those the bloody thing does sound like a ye olde football rattle or a machine gun the mechanic thinks the variable vanes could be stuck or seized he did suggest useing forte turbo cleaner but i am not convinced

If there is no more noise or smoke when you ease off then probably not your turbo. When the common rail switch or/and the harness goes wonky the computer hasn't a clue what to inject and your hippo can make some weird loud injector knocking sounds that almost sounds metallic. if you disconnect it from the switch the computer will set a default value for injection, try taking it for a spin with it disconnected but it will bring the engine management light on and could cost you to have it reset. When you have disconnected the switch look at the connections and see if they have corroded. Good luck .

tincan said:

thanks for the input all new silicon hoses so not those the bloody thing does sound like a ye olde football rattle or a machine gun the mechanic thinks the variable vanes could be stuck or seized he did suggest useing forte turbo cleaner but i am not convinced

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Have a look at the turbo vane actuator through the driver's wheelarch while someone revs the engine. The mechanism should move around 20mm, I think. Ours does.

good call will try when and if it stops raining

redwood said:

If there is no more noise or smoke when you ease off then probably not your turbo. When the common rail switch or/and the harness goes wonky the computer hasn't a clue what to inject and your hippo can make some weird loud injector knocking sounds that almost sounds metallic. if you disconnect it from the switch the computer will set a default value for injection, try taking it for a spin with it disconnected but it will bring the engine management light on and could cost you to have it reset. When you have disconnected the switch look at the connections and see if they have corroded. Good luck .

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will try anything thats cheap many thanks for the advice but if there was a problem with the wireing/switch surely i would get some sort of fault code or mil light??

not always