Godlykepower
Member Since: 23 Dec 2016
Location: Royston, Hertfordshire
Posts: 34
  
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| Help! I’m down on power, but have no fault codes |
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I’ve got an ‘05 D3 TDV6 which I’m preparing for overland use (it was on the front cover of LRO a couple of months ago. It’s wanted for nothing, and has been faultless in the 4 years I’ve owned it, but I’ve done loads of preventative maintenance.
Just come back from a week around Northumberland and Scottish Borders (it was meant to be The Alps for two weeks, but I got COVID the day before we were meant to leave 
Whist away, I was losing a lot of speed and struggling up some hills - I thought it was just me driving like a driving instructor, and trying to move a vehicle whose weight has increased somewhat from standard with all the kit I carry etc.
Plugged in the GAP tool, and got “P0299 - turbo underboost.”
A couple of weeks ago I was getting a noticeable whistle through the raised air intake, sounding very much like a police siren, but that has stopped now.
My local indie had it for a pre-Alps inspection, and noticed the tube actuator was a bit sticky, so they freed that up.
I can confirm that the actuator seems to be moving freely enough.
I have always stayed on top of keeping MAP and MAF sensors clean, but changed the MAP anyway this week.
I am trying to be methodical in tracking down the cause of my issue, before replacing the turbo (which I’m not overly happy about, but have no problem doing it if necessary!) but I only have a limited mechanical knowledge.
I have ZERO lights on the dashboard, no restricted performance, or anything to suggest it wasn’t running beautifully, until I try to get up to speed - I couldn’t get over 55mph on a run between roundabouts on a dual carriageway, where it’s easily hit 90 before.
So far this week, I have:
- changed the fuel filter in case it was partly blocked/connections were on wrong.
- changed the MAP sensor.
- changed the 3 seals on the throttle body.
- used contact cleaner to clean the MAF sensor.
On Sunday I will replace the intercooler and ensure that all the silicone hoses I have fitted are all still intact, and the hose clips robust etc
The only one of the hoses that are still original, is that little one that a PITA to change near the turbo.
After changing the fuel filter today, I cleared any fault codes, took it for a spirited drive around town, and it *seems* slightly better, but now I have absolutely NO fault codes at all, but it’s still nowhere near perfect.
Before I have the turbo replaced, does anyone have any suggestions of things that I can check and look for first? Or any sort of advice? Propelled across the land in a carriage of no horse drawn, belching Satan’s black wind into our clean and local air.
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 21st Oct 2022 7:15 pm |
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Flack
Member Since: 06 Sep 2006
Location: Preston Lancashire
Posts: 6267
 
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Have the egr's been blanked and did they remove the butterfly valve?.
Flack 
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| 22nd Oct 2022 8:37 am |
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Godlykepower
Member Since: 23 Dec 2016
Location: Royston, Hertfordshire
Posts: 34
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Sorry, yes, I forgot to add that.
They’ve been removed and blanked off, the butterfly valve has been removed, and the throttle body is as clean as a whistle! Propelled across the land in a carriage of no horse drawn, belching Satan’s black wind into our clean and local air.
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| 22nd Oct 2022 9:57 am |
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Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10482
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as you, I'm thinking sticky actuator. (also ensure it moves itself at ignition on and ignition off)
or intercooler/hoses
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| 22nd Oct 2022 10:14 am |
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M3DPO
Member Since: 22 Sep 2010
Location: Notts.
Posts: 8154
 
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Any black smoke when accelerating hard?- if so double check hoses and circlips and intercooler for splits. It can when others can't,
It will when others won't,
It goes where others don't.
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| 22nd Oct 2022 10:45 am |
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Godlykepower
Member Since: 23 Dec 2016
Location: Royston, Hertfordshire
Posts: 34
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No black smoke that I can see Propelled across the land in a carriage of no horse drawn, belching Satan’s black wind into our clean and local air.
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| 22nd Oct 2022 11:00 am |
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