jdumont
Member Since: 03 Nov 2022
Location: Cornwall
Posts: 30
  
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| Restricted performance and binding brakes. Linked? |
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Afternoon,
Last week I discovered my brakes were binding. On inspection found that FR pad backing plate had corroded sufficiently that half the material flaked away. Not my finest moment but a quick fix as I had some pads ready to fit.
I've since heard brake whine, so the binding isn't resolved. Sounds like RR and maybe RL (heard two different pitches at times). Funny thing is that it isn't resolved by using the brakes and will start/stop spontaneously.
I've just now had the dreaded restricted performance error, with codes P004B-77 Turbo boost control solenoid - Mechanical failure - Commanded position is not reachable & P259B-71 Turbo boost position sensor B performance - Stuck high - Mechanical failure - actuator is stuck. Fairly self explanatory.
We've got history with this actuator causing issues. Last year it kicked off on a long drive and eventually led to a cracked intake manifold being caused/found.
My question is am I right in saying that the solenoid is vacuum operated and the brake and actuator issue may be linked?
Plan of action for tomorrow (between school runs!) is to see if the actuator is indeed stuck and whether I can loosen it. What's the best way to do this in a few hours, without pulling the car apart?
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 24th Apr 2024 3:59 pm |
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jdumont
Member Since: 03 Nov 2022
Location: Cornwall
Posts: 30
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Further testing shows that the actuator does move readily just hooking a finger behind it. There's reasonable stroke before pressure builds and it's too hard to push any further. Shaft of the actuator into the valve seems smooth and free to move.
Took it out for a blast and couldn't trigger an RP code in any gear, at any load. Anecdotally I'd say the whining from binding brakes was markedly less on my return.
Had my wife turn the engine on and off a few times with my head under the bumper, near the actuator. First time I heard all the usual clicks at shutdown, but it sounded like the TSOV did a rapid flap back and firth rather than an end to end test. Second and third attempts showed no movement (couldn't see on first) but also no noise.
All a bit inconclusive to be honest! I'll keep an eye out for more details, but if anyone has knowledge to still chip in on vacuum being a shared issue I'd be very grateful.
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| 24th Apr 2024 6:49 pm |
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