2000 golf TDI sudden power loss

[Brutalitist]

I have had my golf for just over a year, i bought it used.

for the last month or so when i try to accellerate over around 80kmh in hot/humid conditions my car seems to loose power, almost like my turbo dies or something, i can usually go around 110km/h on the highway unless i hit a hill in which case i cant go over 100, it's starting to get pretty annoying as, after i get back into town, i cant accellerate at all, getting to 60km/h takes about a 1 min and it feels really gutless, it has never stalled on me as i read in other threads, however i was wondering if you guys could help me.

Another interesting point, i drive about 45 mins of highway driving to school every day, on the way too school it has never died, however 70% of the time i drive home it will loose power when i try to accelerate to highway speeds.

Thanks

[boschmann]

It sounds like a bad MAF sensor or possibly a clogged catalytic converter. Is the check engine light on?

[Brutalitist]

nope, however the very first time this happened was when i turned on my AC last year around this time, at that time the check engine light came on, however after a day or 2 it went off and the power returned. Since then i haven't turned on my ac fearing it would worsen the problem

EDIT: i was just reading around on google/other forums, and one guy described a similar problem to mine, and he had is turbo's multi function switch replaced, does this sound like it would make sence to u guys?

[boschmann]

If it was a turbo problem I'd expect excessive black smoke, hows your exhaust look when it's sluggish?

[Brutalitist]

well i haven't really checked as im usually driving it and can't see, next time it happens when i get out ill leave it running. and post the result

[boschmann]

One thing you can do is to unplug the MAF. By doing this you actually force the ECM to go and use default values. If the MAF was bad driveability will actuall slightly increase (not to the point of a good MAF, but better than a bad one). This will cause a code to be set, but at least if driveability increases you know what the problem is. You will have to have someone clear the code after you replace the MAF, but it will probably go out after some time of driving. I do not reccommend unplugging the MAF as a cure.

[seniorbigs]

It does sound like a faulty MAF sensor. They can cause driveability problems without a check engine light coming on.
Another common problem on the TDI is carbon buildup in the EGR cooler. When extreme it can almost choke the intake completely. Remove the EGR valve to inspect the intake for carbon.