HELP! I have no boost!

Grant

Grant

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Was driving yesterday afternoon and went to overtake a car. I dropped a gear, pulled out and floored it and what happened next can open be described as hitting a brick wall!

I immediately pulled over to the side of the road and tried pulling away again, but the car would not boost at all. Also, the idling was very lumpy.

Plugged in VAG-COM and an error message of MAF sensor signal to high - Intermittent (or something like that) was recorded.

On idle the engine seems like it wants to die. When I disconnect the MAF sensor it idles fine. I tried driving with the MAF disconnected but I'm still getting no boost. So off to Audi tomorrow to get a new MAF sensor, but I have no idea why I'm not getting any boost. Any ideas?

Thanks
Grant
 
sure you not got a hose blown off?

if it has you should be hearing the whine from the turbo

id be checking around the hoses, onto the ICs etc.
 
I have had similar twice...

Once was some form of very nasty limp mode...no boost at all until reset by VAG Com...

The other was an IC hose blown off.

If the engine is rocking hard on it's mounts at idle..it's likely to be the latter.

What hapens is the MAF sees air entering, which is not translated to air seen by the engine...and it doesn't play ball...no boost, no idle etc.
To prove...unplug the MAF...if the idle steadies out, but there is still no boost / power..you most likely have a hose off / burst.

Under the hose off condition, mine would idle perfectly, pull smoothly - but with no power...and there was no whoosh of air as to indicate a split hose as indicated by many 'experts'.

It's worth a go unplugging the MAF sensor to see if you can get any more info.

BTW, the only error I had was a MAF related DTC too!

The problem was found when the man from Audi fitted a new MAF and the problem remained.

Best check, before you buy a new MAF!!
 
[ QUOTE ]
sure you not got a hose blown off?

if it has you should be hearing the whine from the turbo


[/ QUOTE ]

I had no such noise on mine...absolutely nothing to indicate a hose off.

Everyone said you will be able to hear the leak...but I couldn't.

But, a hose off it was...drivers side IC outlet hose...
 
same here. both ends. fixed top one and fixed it so tight the other end blew off.

doh.

anyway swapped them out for Samcos and never had an issue since.

noise was like an asmatic wheeeze which raised with revs. quite audible.
 
Thanks for the responses guys!

I reset everything using VAG-COM and disconnected the MAF - car idles like it should but still no boost.

I had an FMIC fitted a few weeks ago so I'll go have a closer look to see what I can see.

I'll keep you posted!

/ubbthreads/images/graemlins/beerchug.gif
 
[ QUOTE ]

I reset everything using VAG-COM and disconnected the MAF - car idles like it should but still no boost.


[/ QUOTE ]

Sounds familiar...


[ QUOTE ]

I had an FMIC fitted a few weeks ago so I'll go have a closer look to see what I can see.


[/ QUOTE ]

Check the hose where the air enters the FMIC...that's where mine went.

Who's FMIC are you using?

Star P's?

If so, I'll bet that's where the hose has popped off...

I would cancel the visit to Audi though...save yourself the time / money....I bet your MAF is fine.
 
FMIC fitted at Star.

I think I'll need to get some of those hi-strength jubilee clips you had Glen! Where did you get those from?
 
Just had a look...

The pipe for the FMIC has come loose... the pipe after the FMIC.

Looks like a bumper off job for me tomorrow!

Thanks again for your help!

Grant
 
*** UPDATE ***

I took the bumper off last night and found the problem!

The 45 degree elbow from the SMIC that connects to the 90 degree elbow into the FMIC had seperated.

This is hardly surprising considering the company who fitted it, didn't even bother to replace the original jubilee clip which was all rusted! Disappointing!

I took photos, so I'll get them posted soon!
 
Glad you got it sorted mate! /ubbthreads/images/graemlins/beerchug.gif
 
Had the same issue. No boost at all, although the car drove perfectly.

Turned out that an air leek caused the turbo to overboost which eventually triggered some kind of limp mode and no boost at all. Symptoms where noticable increase in power (and air/turbo noise) followed by complete (and instantaneous) loss of boost several weeks later but no warnings on the dash.
 
also, look at the pipes on the dump valve (situated top right hand corner just above the turbo). i replaced my OE dump valve today as the casing was split and causing me problems, and when i put the pipes back on, one of them came loose whilst i was driving, and "limp" isnt a strong enough word for what it felt like, more towards "held back by a jet engine".
 
I’m having similar problems too with no boost. Revo found out I had problems with my MAF which they reset. I’ve now got the engine management light on! I need to get my car diagnosed to find out what the exact problem is, would Audi charge for this?
 
rraghvani said:
I’m having similar problems too with no boost. Revo found out I had problems with my MAF which they reset. I’ve now got the engine management light on! I need to get my car diagnosed to find out what the exact problem is, would Audi charge for this?
Click to expand...

read back to what i said previously in my post on this thread, i mentioned about the dump valve having hairline cracked on the casing was giving false readings between the MAF and the sensor that follows the dump valve.

check the pipes, fittings and the dump valve (best way to check it, take it off and blow into the holes - if u hear air coming out its broken)
 
Since the weather change, my turbo now seems to work all the time! Could this be due the MAF being dirty / clogged up?
 
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