Down on power since mot test!

[Broggy]

I had my 2008 3.0 SD MOT'd a couple of days ago- emissions etc passed fine. I hardly drive the car as its the missus's car really. She told me tonight that the car is down on power, and so I have just taken it for a drive on a long straight road, and it seems not to be boosting at all, other than the odd attempt where it seems to try to boost momentarily. There are no warning lights displayed at all, and it ticks over smoothly.

I'm going to book it in with a garage tomorrow, but in the meantime I'm having kittens over what it could be!
Strange that it has started to play up only a day after being in for MOT, Is it normally revved hard for emission testing? I wasn't there when they did it but it is a bit of a coincidence.  The car has covered 78,000 and I have only had it a couple of weeks, but it has run perfectly to date.

I've also called out Greenflag this eve to see if they can diagnose and/or fix- wish me luck!!

I've rung a pal that said it may well be some vacuum hoses that have split, and so I'll be happy if that's all it is. Any other pointers would be appreciated. I'll report back how I get on with Green Flag!

[Broggy]

Well, Greenflag mechanic looked at the car and put on a basic diagnostic tester, and it came up with fault codes: 4180 turbine control flap activation, 4212 glow plug cyl 1 activation, 4222 glow plug cyl 2 activation.  There was left air cleaner exit pipe very loose/almost disconnected to the air cleaner box, but despite re-attaching, the car still lacks power/doesn't boost.

Will book it in tomorrow and hopefully get to the bottom of it.

Chris

[martin33100]

[quote="Broggy"]
Well, Greenflag mechanic looked at the car and put on a basic diagnostic tester, and it came up with fault codes: 4180 turbine control flap activation, 4212 glow plug cyl 1 activation, 4222 glow plug cyl 2 activation.  There was left air cleaner exit pipe very loose/almost disconnected to the air cleaner box, but despite re-attaching, the car still lacks power/doesn't boost.

Will book it in tomorrow and hopefully get to the bottom of it.

Chris
[/quote]Glow plug faults on the 3L diesels is very common, the glow plug controller usually goes down as well, had it on our 3L E91 and also have it on our current E70.

[Broggy]

Thanks for that. I think I might replace the glow plugs and module anyway so I know they should be reliable for a while, and hopefully it might still be a failed vacuum hose etc.

[Nine468]

I wouldnt have thought the glow plugs going down would make the car feel down on power, although the "4180 turbine control flap activation" sounds suspect... I hope its not too serious, or expensive..

[grumpywurzel]

It's not the glow plug causing your issue, these diesels are forever killing the plugs and/or the controller. You will get white smoke on start up and a slight misfire or uneven tick over until the cylinders are warmed up.

You have an issue with the turbo, as you have already had the codes read. I find it strange that during an MOT they have dislodged any pipes but strange things happen.

Not a e70 guru, turbine control flap? Is that a new name for a dump valve or is this the swirl flap? Dunno... Paging X5Sport!!!!

[grumpywurzel]

Been googling e70 turbine control flap. Happening on a few cars and the fix is to replace the actuators.. Sorry I am no help

[X5Sport]

Part of the MOT Test for diesels revs the nuts out of the engine - engines failed regularly when this smoke test was brought in but less of an issue now - and it could just be a sticky waste gate actuator as the engine is not normally used in that manner and the actuator is stuck.  It will reduce the boost by dumping pressure overboard.  You should be able to hear it I would have thought?

Only a partly educated guess at this though as I'm not certain of what they mean.  Not swirl flaps though.

[Broggy]

Thanks for the replies. It is getting looked at tomorrow night by a BMW tech so I'll hopefully find out what the issue is.

[Broggy]

Well, I have had the car fixed this evening!  It was one of the turbo vacuum pressure control valves that had failed. I replaced the pair of them as the oem replacements are updated ones that are a better design. I also had all the glow plugs and the module replaced . The vacuum pipes were looking a bit raggy so we upgraded them to silicone hoses. The car drives perfectly now! So relieved it wasn't anything more serious!

If anybody needs a mechanic in the North Yorkshire area, I can highly recommend the guy I use. He will travel to home address to fix, and he very clued up with BMWs, and isn't ham fisted which is a bonus. PM me if anyone wants his number.