Good source vacuum on a CR?

Will27

Well-known member
Joined
Jul 25, 2017
Location
New Zealand
TDI
'06 Golf TDI, '08 Caddy TDI, '13 Passat Alltrack
Hi all. I've been feeling that my B7 passat with CFGB engine has been a little bit sluggish compared to what I would expect. My older B6 passat with the same power/torque rating felt better and more responsive. Honestly it feels similar to driving a PD with a small vacuum leak or the N75 not working 100%, reducing fuel economy and reducing low-mid range response and power a bit. I was thinking its probably due to the dieselgate flash done before I got it, but thought I would do a few checks.

My question is, what is good source vacuum for CR's? I'm getting 23inHg at the vacuum pump - is this normal? With PD's I'm used to seeing 27~28inHg. For reference, the CFGB uses the same vacuum pump as CJAA - 03L145100F.

All boost hoses and connections look perfect, no leaks.
Can't find any vacuum leaks with my mityvac. Turbo actuator moves smoothly and when it should.
The check valve between the pump and engine side is working properly and is installed the correct way round.
I have Tee'd into the vacuum system and also disconnected 1 component at a time putting the vacuum gauge in its place looking for any changes, then comparing to connecting the gauge directly to the vacuum pump.

There is no difference in vacuum measurement connecting directly to the pump vs measuring anywhere on the engine side, so I know I have no leaks.

I might be chasing nothing, but it's not like I'm spending money doing it. I figure if there's nothing wrong, I'll have a set of known good numbers for down the road if I need them. Thanks.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
DPF on the car? how many miles on it? Has the EGR system been modified or cleaned recently?

Measure and compare boost requested to boost actual? if the deviation is too great it'll toss a code for a VNT issue.
 

Will27

Well-known member
Joined
Jul 25, 2017
Location
New Zealand
TDI
'06 Golf TDI, '08 Caddy TDI, '13 Passat Alltrack
Yes, DPF and EGR on the car. No work done recently. 205k km (~127k miles). The car is driven 75% highway and the shortest normal drive is 40mins ~ 1hr so I'm not too worried about the emissions system clogging up. The EGR valve is a pain to get to on this car so I hope its fine:LOL:

No codes being thrown, will do some logging and see. It just has that lazy feel to it that started me checking things. Source vacuum seems a little low but I don't know if the CR's are different there.
 
Top