1.8T Low Boost

**skipi** · 10-02-2011,05:21 PM

Hi,

I hooked up my VAGCOM to the car and it showing a range of 90-150mBar boost while driving. (1-2psi)

I'm getting no faults.

I can hear the turbo whirring on start-up.

- I checked the wastegate actuator, it's moving as the car is revved.
- I checked the Ohms on the N75 valve, within range.
- I'm pretty sure I've no leaks in the system
- Replaced the DV last year and vacuum lines.

Can any one please advise on what I should check next???

Should I try unplugging the N75 and N249 valves and taking it for a spin?

Thanks in advance,

Skip

**kenney** · 10-02-2011,05:37 PM

try unplugging N75

**skipi** · 10-02-2011,08:08 PM

Hi,

I tried that and it appeared to make no difference

**kenney** · 10-02-2011,08:57 PM

Run the vehicle in 3rd gear give full throttle and take a reading of the AMM value

**skipi** · 11-02-2011,10:32 AM

Tried that, unsuccessfully!
It looks like I'll have to invest in the registered version of VCDS-Lite or find someone to read it for me while I drive.

I'm going to test the system again for any leaks later today and maybe see if there is any play in the wastegate rod. Following that it might be take the CAT off and look at the wastegate flap...

just as well i'd nothing planned for the weekend!

**skipi** · 12-02-2011,12:44 PM

After doing some more research last night, I'm guessing that since unplugging the N75 didn't make any difference, then that is most likely the problem.

I took the chance to retest for leaks in the system. None found

I also took off the CAT to check the condition of the wastegate flap and actuator arm. Excellent condition

There is a bit of play in the shaft, but nothing major (120,000 miles)

I tested the wastegate actuator. perfect

I got my code for VCDS-Lite late last night, so I'll try get the readings later and prehaps test the N75.