Turbo being bipolar

[Moubeid92]

Hey guys i got a 02 gti 1.8t. My turbo usually pushes 20psi., about a few weeks it went into limp mode and would push max 10 psi. Then it came back for about a week pushing 20psi and running strong. Now its pushing barley 15 in the first 3 gears and 4th and 5th 10 psi. Could it be my MAF is acting funny? only code its giving off the "Internal COntrol Module" somthing about the PCM, but this has been around for MONTHS. This turbo problem just happened recently. Any ideas? I would very much appreciate it

[20VCanuck]

Chech for boost leaks,

Use the method in the f.a.q on top of the forum board.

Fix said leaks, then report back.

[Moubeid92]

it cant be a leak, cause the PSI stays the same. If there was a leak wouldnt the psi drop quickly?

[20VCanuck]

leaks in the 1.8t cause it to run funny. If you've never pressure tested your system, you more than likely have leaks regardless of if they are playing a factor in your issue.


You can log to see the g/s reading in the maf, but from the sounds of it you dont have a vagcom.

You can unplug the maf and see if it runs better with it unplugged.



Long story short, pressure test you system, and buy a vagcom.

[Moubeid92]

Where are the most comon places to hve boost leaks?

[VWBugman00]

In the GTI, the PCV stuff generally has a problem with leaking due to rot. Check all the hoses and connections that come off the drivers side of your intake manifold.

[DMVDUB]

You need to find out what those codes actually are. Tis doesn't sound as simple as a leak. Neverless you probably do have a leak somewhere so I won't hurt to find it, but I'll bet it doesn't fix the issue. Scan the car with vagcom / VCDS and post the ACTUAL FULL CODE aka copy and paste.