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in dire need of an organic chemistry lesson
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Discussion Starter · #1 ·
2002 1.8T AWM @ 130K miles


Since last month, I have lack of power in the engine and gears shift at high rev (+3000 rpm). I never had this issue before.
VCDS scan reveals no code at all and reports everything is working normal.

1) Last week changed the MAF with a Bosch OEM but no change
2) Sparkplugs were changed (NGK) just a few months back.
3) Have totally cleaned the K&N air filter with no noticeable change.
4) The O2 sensor was replaced 6 months ago (Bosch)
5) I have aligned the TB with VCDS
7) Have changed the tranny oil a few months back. Used Valvoline MaxLife and flushed it twice to have it as clean as possible.

So what would be wrong and what else should I check/replace to have the power restored and tranny shifts normal again?

:thumbup:


P.S. on the side note, the handbrake is also loose. How can I adjust its cable?
 

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Lack of power is probably the turbo. Use vcds while driving, to actively monitor the boost called for vs. the amount of boost actually present.

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in dire need of an organic chemistry lesson
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Discussion Starter · #3 ·
Lack of power is probably the turbo. Use vcds while driving, to actively monitor the boost called for vs. the amount of boost actually present.
What would be wrong with the turbo? I've always use full synth Mobil 1 oil.
Other than that when the gear is shifting from first to second, there is turbo involved?
 

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Could be the wastegate function, a clogging catalytic converter or damaged compressor wheel. Best to check boost pressure first, then dig deeper if you're not getting expected numbers.

The turbo is always spinning from exhaust gas movement. Positive boost starts after 1,300 rpms and noticeable boost at 2,200 rpms or so. You should get some boost even at granny speeds.
 

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The late gear change could be a symptom of excessive gas pedal travel, which you need due to the low power. Check your brakes for dragging first, and rule that out before looking to the engine. Loose handbrake cable could be a sign one of the rears is stuck, but check all wheels.
 

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in dire need of an organic chemistry lesson
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Discussion Starter · #6 ·
The late gear change could be a symptom of excessive gas pedal travel, which you need due to the low power. Check your brakes for dragging first, and rule that out before looking to the engine. Loose handbrake cable could be a sign one of the rears is stuck, but check all wheels.


All four brakes rotors and pads have been replaced 6 months ago and no issues. So I don't think the brakes are the culprit at this time. The low power is a mystery to me.
 

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in dire need of an organic chemistry lesson
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Discussion Starter · #7 ·
Could be the wastegate function, a clogging catalytic converter or damaged compressor wheel. Best to check boost pressure first, then dig deeper if you're not getting expected numbers. The turbo is always spinning from exhaust gas movement. Positive boost starts after 1,300 rpms and noticeable boost at 2,200 rpms or so. You should get some boost even at granny speeds.
I've never done the boost pressure measurement with VCDS. But I go explore it.
 

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All four brakes rotors and pads have been replaced 6 months ago and no issues. So I don't think the brakes are the culprit at this time. The low power is a mystery to me.
That would not be a good enough reason not to check. jack up each rear wheel and spin them by hand with the e brake off. A slight drag is normal. Should turn freely though.
 
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Check the temp reported by the CTS. If it reads cold, it will keep the car in gear longer and withhold boost.
 

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in dire need of an organic chemistry lesson
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Discussion Starter · #10 ·
OK an update. Per above suggestions, took the rear wheels off today and turned the rotors and indeed they were stuck. Then I noticed the handbrake cable was stuck too. So released and lubed it. Immediately, the handbrake that was loos before was tight and normal again. So put back the wheels and ran the car. Holy shit! it was back to life again. Thank God the calipers were not stuck close.

As a habit, I always engage the handbrake at park. But I'm afraid I got to kick out this habit by not using it any more. Using the handbrake may cause it to jam again.

The bummer is that a few days ago bought a Bosch MAF because I thought it was going to die therefore car has lost power. O'well! you learn.

Anyways, thanks for all the tips. I'm off the hook this time. The execution is deferred :lol:
 

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You are in a rust prone area. Just keep an eye on it. Keep it lubed and clean.
 

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in dire need of an organic chemistry lesson
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Discussion Starter · #12 ·
You are in a rust prone area. Just keep an eye on it. Keep it lubed and clean.
Yes that is correct but snow and road salt have not started yet. I'm now thinking to put some anti-seize grease on it. But as you said that is something I'm gonna keep an eye on.
 

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I had that problem with my 99 that I bought from CT. Remove the e brake lever on the back of the caliper and clean it up good, the reinstall. Then keep a protective layer of grease on it.
 

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Or bracket. It's what connects the cable to the piston at the back. Held on with a nut. Back off the nut, clean it up with a brush and brake cleaner. Then lubricate.
 

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in dire need of an organic chemistry lesson
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Discussion Starter · #16 ·
Or bracket. It's what connects the cable to the piston at the back. Held on with a nut. Back off the nut, clean it up with a brush and brake cleaner. Then lubricate.
Yeah I saw that one and cleaned it as much as possible. But I don't think it can be removed. I cleaned it while in place.
 
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