# 2010 Jetta - P0491 and Combi Valve



## rowlands57 (Dec 21, 2003)

I wanted to post this up as I have found some very valuable information here over the years and figured I'd share my recent experience.

It's a 2010 Jetta with about 45K mikes and the car was throwing a P0491 on cold starts. I tried clearing the code but it came back so my research led me to conclude the combi valve was bad. Prior to this I did have the 'recall' sensor replaced so I felt sure that my problem was not with that part.

The combi valve is a bit of a PITA to replace but not as bad as some other jobs I have done. Some comments that hopefully will help other folks down the road.

The engine cover has to come off before doing this job.
The valve is up on the back of the engine in the general area of the battery cover. You really can't miss it when you see the new one that's going in.
The valve has 2 gaskets but the one's on the car are metal and clip on to the valve so I re-used them and they worked fine.
At first it appears that the job should be done coming in from the drivers side but actually it's easier to come at it from 'over the engine' and work lefty to get at the bolts.
You pretty much work in the dark for the bolts attaced to the block.
The electrical connector is released from below and it's like a lot of VW/Audi connectors. Push it in, gently pull on the tab and then pull it off.
The air hose attached is simple to remove just pinch the clip and remove the hose.
The block bolts are 10mm and the bolts holding on the hard line at the top are torx, sorry forgot the size.
When installing the new combi valve just get all the bolts started first then tighten down as you may need to move it around just a bit to get them all started.
There is a wiring harness that is attached to the very bottom 2 bolts with a 'retainer' of sorts, just be sure to put the bolts through that when re-attaching those two bottom bolts.

As I said the job is a bit of a pain but 'nice and easy' is the way to go and it's really not that bad.

Hope this helps.


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## oefvetVWlover (Feb 22, 2016)

*thanks*

do you have pics of the process?


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