2003 ALH TDI MAF actual higher than specified @ Idle

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Rembrant

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Hi Folks,

I was checking some stuff with VCDS on my 03 Golf TDI today, and noticed something odd.

Car at operating temp, with EGR open (duty cycle @ 61.4%), my MAF specified is 275, and actual is also 275. (Varies between 270-280, but generally very close).
After 2 minutes, the EGR valve snaps shut (duty cycle @ 4.8%), and MAF specified is still 275, but my actual is at 480.
MAF was replaced about 10k miles ago, and seems to reach max specified numbers ok.

According to VW spec, at idle with EGR closed, my MAF actual should be more like 370 instead of 480. Do I have this correct?

Is there anything other than a faulty MAF that would cause this? A mechanical issue? Pressure duct leak?

The car is working just fine, and I'm usually hitting 52 MPG without any trouble at all.

I recently installed a new AMC cylinder head, and I installed a new Mahle turbo about 10k miles ago.

Any ideas?
 
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DrPeter

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Hi,

- You may want to check your air filter, this may cause turbulence before the MAF sensor. You could test with another, known good MAF(OEM) sensor and compare the numbers..

- - If there are no fault codes and the vehicle runs fine with good fuel economy, as stated above, I would not worry about it. Just my opinion... ;)


drpeter
 
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Rembrant

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Thanks for the reply Dr.Peter!

I am not worrying about it very much...the car really does work very well.
It's just that I like to stay on top of things and keep everything tip-top!!

I will check the filter and filter housing, etc to see how everything looks.
I won't buy another MAF unless it gets worse...I'll check once in a while and keep an eye on it.

Cheers,
Rem
 
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Eric

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Closed EGR on the ALH made at least 480mg/H for me. More in the winter. I think the 370mg/H figure is a strict minimum. Maybe they tried to account for a plugged intake manifold and a heat-soaked intercooler :)
 
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Rembrant

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Closed EGR on the ALH made at least 480mg/H for me. More in the winter. I think the 370mg/H figure is a strict minimum. Maybe they tried to account for a plugged intake manifold and a heat-soaked intercooler :)
Haha...I suppose so!
Maybe it's that dense sea level air then...lol. I dunno, but I'll forget about it and carry on with other things!

Thanks guys!

Rem
 
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