07 V50 D5 low power. Please help!

[Andy c70]

As previously mentioned, I think your next step should be to get any error codes read. Mine were p2227 and p0069(barometric pressure and manifold absolute pressure) if it helps and after changing that map sensor it's all been fine over the weekend.

Andy

[kwikuk]

Hi Andy, thanks for the response. Yeah, next steps are codes. I should get my code reader back this week. As is always the case, the one tool I hardly use and it is loaned out.

I’d be happy if it were just the MAP sensor, as these seem to go for around the £30 mark, and look fairly easy to get to.

[Yobbo]

I would be very inclined to check the throttle body and EGR mixer chamber because they can get so gummed up with carbon deposits that airflow can be severely restricted.
When I cleaned mine out the diameter of the hole caused by the carbon was about the size of a 20 pence coin, fair to say I restored a few mooses and the car was running a bit leaner after doing that! It may even be the case that the butterfly flap can barely move...
Bit of a horrid job if you take the whole EGR off but you could easily remove and clean the throttle body which would then give you easy access to the EGR mixer chamber - a bit of a prodding and hoovering then using carb cleaner and small hard plastic brush should free up the worst of it.
To access the throttle body you can remove the air intake (https://www.youtube.com/watch?v=KieVdse36Gk) or have a peak by lifting up the airbox from it's plugs.

I had the pipe which connects to the throttle body blow off on the motorway this weekend - largely the result of me fitting a larger intercooler but if there's any kind of blockage or boost leak form there it could mess with the MAP readings as there will either be
a) too much back pressure
b) not enough air flow

Hope this helps!

[kwikuk]

UPDATE:

I took the car into Autofix, just outside of Newcastle. The chaps there seemed switched on and helpful. After a few days I got the call to say they’d finished diagnostics on the car. Smoke test was fine, no leaks anywhere.

Some codes for both under-boost and over-boost as well as the mass air flow meter. I’d explained that the MAF was a new OEM part and they cleared the code only for it to come straight back. They assumed a broken/chaffed wire to the MAF from the ECM, but after testing they were fine.

They’ve told me that the only thing left it could be is the Engine Control Module.

Now this is where the help ends. They can replace it at the cost of £1200 : or they’ve said I can try looking online for someone to diagnose and repair it. They couldn’t help me with who though, as the place they use doesn’t do ECMs, just other modules.

Does anyone have any ideas?

I’ve seen ECMs on eBay second hand for about £100. Are these coded to the car or plug and play? What, if anything, would I need to do to get it to work in her car?


We’re both really, really starting to lose faith now. If anyone can help us we’d both really appreciate it.

[kwikuk]

UPDATE:

I took the car into Autofix, just outside of Newcastle. The chaps there seemed switched on and helpful. After a few days I got the call to say they’d finished diagnostics on the car. Smoke test was fine, no leaks anywhere.

Some codes for both under-boost and over-boost as well as the mass air flow meter. I’d explained that the MAF was a new OEM part and they cleared the code only for it to come straight back. They assumed a broken/chaffed wire to the MAF from the ECM, but after testing they were fine.

They’ve told me that the only thing left it could be is the Engine Control Module.

Now this is where the help ends. They can replace it at the cost of £1200 or they’ve said I can try looking online for someone to diagnose and repair it. They couldn’t help me with who though, as the place they use doesn’t do ECMs, just other modules.

Does anyone have any ideas?

I’ve seen ECMs on eBay second hand for about £100. Are these coded to the car or plug and play? What, if anything, would I need to do to get it to work in her car?


We’re both really, really starting to lose faith now. If anyone can help us we’d both really appreciate it.

[Yobbo]

Right okay, I thought I had mentioned this before but looked back and haven't -

Please check the wiring loom of the connector to the turbo actuator.
Because of the sharp angle of the wiring to the connector and the amount of heat generated in the area, it is seemingly that case that these conditions are causing the wires to become brittle and break off - this can cause intermittent boost, no boost at all, and loss of boost when the car is up to temp.

I now know of four, possibly five cases, one which have arisen in the last week, I dare say this is becoming a common fault!?

Mine personally hasn't gone, but I'm currently spraying WD40 on the wires haha...
When I get a chance, I will bring the loom down a little to reduce the stress on the wires as there appears to be a cable tie that straps the wiring loom to the cold air pipe, I'll also consider some other form of protection/reinforcement in some self-fusing rubber tape to go around the protrouding collection of wiring strands.

[kwikuk]

Originally Posted by Yobbo

Right okay, I thought I had mentioned this before but looked back and haven't -

Please check the wiring loom of the connector to the turbo actuator.
Because of the sharp angle of the wiring to the connector and the amount of heat generated in the area, it is seemingly that case that these conditions are causing the wires to become brittle and break off - this can cause intermittent boost, no boost at all, and loss of boost when the car is up to temp.

I now know of four, possibly five cases, one which have arisen in the last week, I dare say this is becoming a common fault!?

Mine personally hasn't gone, but I'm currently spraying WD40 on the wires haha...
When I get a chance, I will bring the loom down a little to reduce the stress on the wires as there appears to be a cable tie that straps the wiring loom to the cold air pipe, I'll also consider some other form of protection/reinforcement in some self-fusing rubber tape to go around the protrouding collection of wiring strands.

Thanks Yobbo. I’m going to have a look myself when I get it back. The garage said it was a four wire harness that goes to the actuator and that he’d done a positive continuity test on all of them. Which is what led him to say it’s a fault in the ECM.

I just don’t know if I can buy a used one and it’s plug and play? Or whether it needs to be coded etc.

Also, although WD40 is great for pretty much anything, it’s bad for wires. It eventually makes the sheathing brittle and powdery. GT85, Corrosion Block or ACF50 is the way to go. Keeps off the moisture without attacking the rubber/PVC.

[Yobbo]

If the garage have already done continuity checks on that then I'm a bit stumped, if the actuator was knackered there would be codes coming back from VIDA...

Really hope it's not what they suggest!

All the best,
Dave