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Jonhamil

Lack of Power / Almost Stalling - Checked MAF and Vacuum Hoses

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So yesterday, I pulled up to a set of lights and slowed the car quite quickly. When we stopped, the car laboured and nearly stalled.

 

I searched the forums and found that this is usually because of a dirty MAF sensor or can be because of a lead in the vacuum hoses. Fortunately I've been meaning to change the vacuum hoses and had all the gear.

 

I cleaned the MAF with electrical contact cleaner and replaced all the vacuum hoses (apart from the one that runs right across the front subframe of the car.

 

The car still behaves almost exactly the same and I have noticed a very faint 'whistling' if I accelerate hard and when I take my foot off the accelerator after a period of reasonably fast acceleration. 

 

Car has done 160k and I've got a very low mileage turbo that I have also been meaning to fit. I'm guessing that's most likely at fault but would be grateful if anyone else has any experience to suggest something else?

 

Many thanks,
 

Jonathan

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2 hours ago, dj1233 said:

What engine code is it you have? for 2007 it could be M47D20 or the N47. 

Sorry I should’ve said-it’s on N 47

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44 minutes ago, dj1233 said:

Rule out the MAF by unplugging it and see how it drives. The car will run on a 'default map', so will still work and won't do any damage. 

Thanks – yep already done that and ruled out MAF and also vacuum hoses

 

I’m thinking must be the turbo but is there anything else that it could be?

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On 6/29/2020 at 12:32 PM, dj1233 said:

have you got an OBD reader that can read the boost sensor? The torque app does this, but you need a Bluetooth OBD adaptor too. 

Yep - sorry for slow response.

 

At idle it's stuck at 95% boost, it dips when I blip the throttle.

IMG_7989.jpg

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Well.. i took the intercooler off today to check it and pipes for leaks - all looks good though.

 

Tomorrow the turbo's being swapped out - I had a good one from a breaker a while ago which have been meaning to swap in.. Fingers crossed that sorts it out..

 

I don't understand why Dr Gini is showing 95% boost pressure under 0 load...

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Electrical contact cleaner leaves a lubricating film so you have probably done the maf more harm than good.

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Just now, GoNz0 said:

Electrical contact cleaner leaves a lubricating film so you have probably done the maf more harm than good.

Yep - I did wonder about that - but others have had success, so I wasn't sure.

 

Have done it with proper MAF cleaner yesterday, so we will see when it all goes back together tomorrow. Although will never know if it was the MAF or turbo..

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1 minute ago, Jonhamil said:

Yep - I did wonder about that - but others have had success, so I wasn't sure.

 

Have done it with proper MAF cleaner yesterday, so we will see when it all goes back together tomorrow. Although will never know if it was the MAF or turbo..

Yeah, that or brake cleaner as neither leave a residue. 

 

N47 are prone to the turbo linkage sticking, it is a known issue as BMW sell the linkage but it's unlisted funnily enough!

Take the actuator off (don't lose the circlips) and check the linkage moves free?

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2 minutes ago, GoNz0 said:

Yeah, that or brake cleaner as neither leave a residue. 

 

N47 are prone to the turbo linkage sticking, it is a known issue as BMW sell the linkage but it's unlisted funnily enough!

Take the actuator off (don't lose the circlips) and check the linkage moves free?

Thanks - I'm literally just about to jump back onto the turbo job - will do and report back this eve :-)

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12 minutes ago, GoNz0 said:

Yeah, that or brake cleaner as neither leave a residue. 

 

N47 are prone to the turbo linkage sticking, it is a known issue as BMW sell the linkage but it's unlisted funnily enough!

Take the actuator off (don't lose the circlips) and check the linkage moves free?

Actually - just thinking - as I'm putting on a low-mileage turbo from another car, it would make sense to apply grease to the linkage to prevent it seizing - would you recommend? I saw your post on the bmw kit - do you have the part number pls? it was just cut off the picture.

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Never got a reply to it m8.

The only thing with greasing it is the temps it has to cope with, copper grease isn't quite enough. I use the same stuff I put on turbo bolts. Permatex 77134

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If the linkage is sticky use a foaming oven cleaner to get it back to as new condition before greasing.

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19 minutes ago, GoNz0 said:

Never got a reply to it m8.

The only thing with greasing it is the temps it has to cope with, copper grease isn't quite enough. I use the same stuff I put on turbo bolts. Permatex 77134

Ah thanks - the linkage part number you quoted on the other thread was 11657823724 -

 

Have just ordered the Permatex stuff  - thank you for that - am putting the turbo on today, but can always re-seat the bolts with proper grease next week

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20 minutes ago, GoNz0 said:

If the linkage is sticky use a foaming oven cleaner to get it back to as new condition before greasing.

aka Mr Muscle or similar?

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Yes m8, I have used the poundshop versions that are identical ingredients. 

If you don't have new turbo bolts it may be an idea to get some :)

 

(You can use it for sticky turbo vanes as well)

 

FYI the last N47 I fixed by cleaning the linkage and permatex nickel grease is still working perfectly 6 months on :)

 

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1 hour ago, GoNz0 said:

Yes m8, I have used the poundshop versions that are identical ingredients. 

If you don't have new turbo bolts it may be an idea to get some :)

 

(You can use it for sticky turbo vanes as well)

 

FYI the last N47 I fixed by cleaning the linkage and permatex nickel grease is still working perfectly 6 months on :)

 

Cool, thank you so much for all the advice.

 

I just got to the final stage of taking the old turbo off - I haven't seen bolts like this before - are they splined? (I have done splined socked heads, but not bolt heads) They're very rare..

IMG_7990.jpg

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19 minutes ago, Jonhamil said:

Cool, thank you so much for all the advice.

 

I just got to the final stage of taking the old turbo off - I haven't seen bolts like this before - are they splined? (I have done splined socked heads, but not bolt heads) They're very rare..

IMG_7990.jpg

It’s ok - figured it out, standard 12 PT socket works 

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2 hours ago, Jonhamil said:

It’s ok - figured it out, standard 12 PT socket works 

Yep ^_^

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