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Discussion Starter · #1 ·
My 1.8t seems to have one hugeeeeeeee flat spot between 3-4000rpm, any one else suffer from this? Or does my car have a problem ? [:'(] Its AUM engine code BTW
 

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MAF? Unplug and see how the car runs. If it runs better, get the MAF changed. And check your hoses.
 

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Discussion Starter · #3 ·
Will it harm the engine if i run the engine round for 5 mins without the MAF?

So i take it im not supposed to have these flat spots!

The turbo makes a lot of whistling so it could be the hoses, but it pulls reallllly strongly! well untill the flat spot, then it will get past it n pulll more! So im ot sure if its the hoses

Another thing is its only there 80% of the time, sometimes its not there at all?!

head puzzler for sure [:mad:]
 

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Will it harm the engine if i run the engine round for 5 mins without the MAF?

So i take it im not supposed to have these flat spots!

The turbo makes a lot of whistling so it could be the hoses, but it pulls reallllly strongly! well untill the flat spot, then it will get past it n pulll more! So im ot sure if its the hoses

Another thing is its only there 80% of the time, sometimes its not there at all?!

head puzzler for sure [:mad:]
No, AFAIK it won't harm your engine, although it shouldn't be run without it for a long time! It will probably register a fault that will be picked up on a diagnostics machine but it can be reset by disconnecting the battery for a short while (make sure you've got your radio code though!). If you reset you'll need to give the car a good drive afterwards so that the engine management system can "learn" its settings again (all gears, throughout the rev range).

If you want further info, have a look at the "How To" forum - there's lots of info on there about cleaning the MAF. Here's one of many:

http://www.uk-mkivs.net/forums/170890/ShowPost.aspx
 

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Discussion Starter · #7 ·
Cheers very muchos dave but what does AFAIK mean ?[:$] While i am on the subject what does OEM mean ? [:$][:$]
 

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Discussion Starter · #8 ·
darth so if you have it , it can be a turbo problem (Obviously lol) i ran the car at lunch with the MAF unplugged, it drove exactly the same just stank of petrol when i was idleing and done 11mpg ! LOL
 

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Mine's got exactly the same symptoms, whisting turbo,a flatspot at 3000rpm and not holding boost.

JBS had the car for the day, checked everything MAF/Throttle body, DV, N75 etc, couldn't find any problems/faults. It's going back for the turbo to be replaced on Monday [:S]
 

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Cheers very muchos dave but what does AFAIK mean ?[:$] While i am on the subject what does OEM mean ? [:$][:$]
AFAIK=As Far As I Know. OEM I think refers to a manafacturers standard item.

So the test run rules out the MAF. I think I'm right in saying that if your turbo is sounding pretty loud it could be a split in the DV. or possibly a faulty N75 valve?
 

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Mine's got exactly the same symptoms, whisting turbo,a flatspot at 3000rpm and not holding boost.

JBS had the car for the day, checked everything MAF/Throttle body, DV, N75 etc, couldn't find any problems/faults. It's going back for the turbo to be replaced on Monday [:S]
OUCH![:'(]
 

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Discussion Starter · #12 ·
Thank god mine has warrenty, i dunno if its the turbo/hoses though as it does pull really well when not in the flat spot! And the whistle although loud isnt abnormally loud in my opinion anyway!

Because my car has a warrenty can i get it checked out for free as i think this may be a problem? Or do i have to pay money for it to be checked?

Dave let me know if your new turbo fixes this mate!

So is the 1.8t not supposed to have this flat spot? Could it just be turbo lag?
 

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if it's got a warranty, take it to the dealer and tell him the problem that you're experiencing. If it's noticable they should sort it. But make sure they know that you'll be expecting it to be covered under warranty in case they try to charge you !!

Let us know how you get on.
 

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Discussion Starter · #14 ·
The only thing dave is it isn't a VW warrenty it is an extended on i have taken out through the Car dealers i bought it from.

Sooooo.... I will have to contact the car dealers i bought it from and hope for the best [:(]

I Will check the hoses etc when i get in from work, but im pretty sure its not down to them, but hey i wont no till i check will i!

So you dont think its down to turbo lag?

I cant imagine it being a knackered turbo as there supposed to be good for 100,000+ miles and my car hasn't even done 30 thousand miles yet, the engine is just about worn in! LOL
 

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Difficult to say without experiencing it but see what the dealer says. If it's a reputable place you should be ok I'd have thought.
 

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Discussion Starter · #17 ·
Ok ive check all round the engine, everywhere i cant see anything wrong everything is on tight, no splits in hoses ect.

I Also done a re-run without the MAF connect again made no differnce!

Come on some one must know about it?

Just wanna no if its trubo lag or a problem ? [:(]
 

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I could be wrong here, but if you have tried it without the MAF connected and there was no difference then the MAF is your problem. When you disconnnect the MAF, the car should feel flat as the engine is in 'get home' mode. If you reconnect it and the engine still behaves the same, then the MAF is as much use as not having one - ie its f***ed

I know when I disconnect my MAF, the car feels really slow - I mean I know its a diesel but even still!

Regarding turbo lag, surely that should only happen at the beginning of each gear, as you are waiting for the turbo to spool up. If it is turbo lag it would be due to a loss in pressure which is not within normal operation.

None of this is gospel as its just my understanding and Im certainly not an expert.
 

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Discussion Starter · #19 ·
Cheers Scruff [:D] I know i always thought well whats the point in having the MAF if you can disconnect it and the car will run fine LOL But a lot of people say if the car runs better with it connected its your MAF, even garages say that lol.

Thats when i get the flat spot when i change gears! It last from 3000-4000 rpm If i change gear at lower revs i wont get the flat spot, only occurs when i am ragging it!
 

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I guess if your MAF is REALLY knackered then it could be sending all sorts of crazy data making the car worse than not having one at all, but the engine cannot run well without the MAF as the ECU is not getting all the inforamtion it requires to do its magic.

Does Turbo lag usually last a thousand revs?! I wouldnt have thought so, unless you're running a turbine in there?!

I would gues the only way you're going to be sure is to get hold of a new or working MAF and give the car a spin. Got to be cheaper than turbo replacement, if its not the problem, well you have a spare MAF...
 
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