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320d down on power.

4K views 26 replies 7 participants last post by  SnackBox93 
#1 ·
Hi guys.

Having a power issue with my n47 320d 177.

Car has, dpf gutted, EGR blanked and swirl flaps removed. Mileage is 113k miles. Not showing any fault codes.

Had it on a dyno a few days ago and it only put out 147bhp. Not surprised either, it's low down power isn't the best.
Remap guy still put the remap on but told me to take it easy as he suspects it's the turbo actuator. Also didn't run it after remap to be safe.

Brought it to BMW specialist today who had it for over two hours trying to diagnose it.

He feels that it's not turbo related but MAF related. He swapped one from another car he had there and said he felt it drove a little better.

When I got home I swapped my MAF with the one from my dad's 320d (which drives better than mine with 160k) and I noticed a slight improvement but not all that much. Certainly not a +200 BHP car. Maybe his isn't great either ? Both mafs are dated 2008.....

Could a bad MAF really knock 20-30 BHP off a car ?

Can the actuator be faulty while not showing fault codes ?

And could that intercooler pipe (pictured below) be the cause ? I've being told it's quite normal.

Cheers.

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#3 ·
Oil in the intercooler pipe is quite normal, but the oil splatter around it would suggest it's not sealing, which would definitely cause a loss of power.
 
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#6 ·
I am not a mechanic but swirl flaps would never have them removed on a n47 intake manifold. That is not advisable on the way they work. If this low power problem have started since car had that done I would related to that. About the maf you could try remove and clean it as it would be good enough once cleaned to see a difference. Just though to give my opinion and I know I could be wrong but someone more pro can possibly advise better

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#7 ·
Yeah I agree. I'd rather have them but it's not worth the risk of them breaking. I was at one stage considering of the remanufactured manifolds from Germany on eBay.

Either way there's no way flaps would knock 30hp of a cars power otherwise nobody would be getting them done.
 
#9 ·
Got into the car today and as I took off it was back to its normal power. Didn't last long unfortunately. Once in a while it does tend to happen. Maybe it is the actuator ? Never heard of a vacuum leak operating on a part time bases 😅

Rubbed a bit of tissue around the intercooler pipe earlier and there was definitely fresh oil on it. I dread to think what's inside the intercooler 😬
 
#13 ·
Maybe the oil is clogging the hole ...

Get the intercooler off and clean all the air intake system while you're at it including air oil and especially fuel filters.

I can't understand why you have a map put on a car that's having issues ..
 
#20 ·
So I left it in with my main BMW machanic today and he has no idea himself either what's going on, he's quite baffled tbh. Of all the tests he ran with inpa or ista he said everything appears to be perfect.

He says it definitely isn't driving properly or as he put it it's almost like it's just the 2.0l moving the car without a turbo after 2800 rpm.

He has suggested that I could have my turbo sent off to be tested and take things from there.

If it's not the turbo he's not what else it could be.
 
#21 ·
Took the map sensor out earlier and it was caked in shit. Dunno what to make of it as the EGR is mapped out and the manifold was cleaned last November when the flaps were removed.

I've a suspicion now that even though the EGR is mapped out that it's somewhat stuck opened. That even possible ?
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#22 ·
Took the map sensor out earlier and it was caked in shit. Dunno what to make of it as the EGR is mapped out and the manifold was cleaned last November when the flaps were removed.

I've a suspicion now that even though the EGR is mapped out that it's somewhat stuck opened. That even possible ?
View attachment 274022
If it's mapped out, get yourself a bypass kit and have away with it.
 
#26 ·
From last week they've began connecting OBD2 scanner to search for fault codes to fail people.

I could go on all day about how anti motoring our government is. The import market for any Euro 5 diesel or older is non existent anymore due to the NoX tax on imports.
 
#27 ·
Bought a new MAP sensor today. Don't intend on fitting it until the manifold is cleaned and I find out why its gunked up after only being cleaned 6 months ago. Just waiting on a nice day to properly go through things.

Plan to start with making sure the EGR is indeed shut and not letting anything past, then move onto the intercooler and boost pipes and then attempt to remove the manifold and cleaning it and the anti shudder valve. If that fails then I'll probably have to accept that it is turbo related.

Called my mechanic back the other day and after speaking with the remapper they both still maintain that it's most likely the turbo actuator 😩. Remapper says that he's seen it on cars that don't do a lot of motorway miles which is the case for me.

I'm just intrigued that I've no fault codes, turbo isn't making any bad noises or smoking and that the actuator test on inpa/ista didn't suggest anything was wrong.
 
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