Hi, all had my car read yesterday, and I've got code p3138 which is variable intake manifold, switchover valve; regulation difference. Has anybody had this fault before and could shed some light on it for me please? I've had the glow plug light flashing that's why I had the codes read. 

I would advise running a fuel cleaning solution through the engine and also one for the intake as it sounds like the valves are sticking with carbon build up.

Possibly try Terraclean treatment and I believe that they come out to your home or workplace to clean the engine through

Thanks for th reply Trevor, I have a fuel cleaner ready to put it just waiting to use up my remaining diesel. For the intake what solutions are out there for that as I've never owned a diesel before I've always been a petrol kind of man. I was maybe thinking of a terraclean as a last solution. 

Hi, I've got the same error p3138 in my audi a3 8p s-line 170hp. How did you figure out to fix this problem?

On 4/18/2019 at 9:59 AM, Serdar said:

Hi, I've got the same error p3138 in my audi a3 8p s-line 170hp. How did you figure out to fix this problem?

Hi, my car eventually went Into limp mode took it back to where I bought it from (still under warranty) had it looked at and the dpf was fully blocked. I went 50/50 with the owner and had dpf delete and remap. Not one problem since. Coming up to two years soon

Hi I got an Audi A3 2007 1.8tfsi I got the p3138 code It comes up as switchover manifold valve what das a switchover valve look like please anyone