Model: '02 Jetta TDI std. ALH 120,000 miles, Recently new timing belt. After exiting the freeway, about a half mile going around 25 mph, we Heard a sudden noise (about the sound LEVEL squeeling brakes or a starter motor makes. Sounded like it might be turbo blades exploding, or a water pump breaking down, or transmission problems, etc. I immediately stopped and looked on the ground and under the hood, but saw nothing. Started up again and drove around the block, everything seemed normal. Next day going up a hill I normally take with ease in high gear, I noticed a pronounced lack of power, having to shift down to 4th and even 3rd. My non-expert diagnosis was it must be the turbo charger. I started removing it with engine in the car, but realized I would have great difficulty putting in back on, so removed engine. Examined turbo. Everything seems OK. Blades not bent. No debris. Drained crankcase oil. No filings or fragments. Camshaft looks OK. Timing belt looks OK. What could cause the noise, AND a major lack of power?

• Turbocharger bearing failure (could also cause air leak in turbocharger)
• Other belt-driven accessory bearing failure
• Torque converter - blown blade seal (automatic transmission)
• Blown head gasket (whistles on initial failure, gap widens after shut-down and silences whistle, however, would probably now make a noise similar to an exhaust leak)

Hi,
Firstly on this model vehicle the timing of the valves and the injector pump can only be checked with a diagnostic tool. The squealing sound could have been a number of things - Loose fan-belt, out of timed injector pump. The loss of power has to be attributed to the timing of the valve train and the injector pump, as I said previously this can only be correctly check by a diagnostic tool.
However because the engine is out, this will be difficult to do now.
Let me know if you need more information.
Thanks
Jason

Check the main bearings and end caps on the Crank. You will have to remove them for this check. It sounds like you spun one of the bearings on the crank. With that kind of mileage they are due for inspection and change.

The items to check are
Waste gate on the turbo Please email me the turbo model # Example: G3

EGR valve (stuck open or not moving freely) / need to remove carbon in EGR valve (if equipped in emission state / country) Clean EGR passage tube.
REMOVE ALL CARBON with WD-40 or PB Blaster

Check for vacuum leaks.
YOU MUST replace EGR base mount gasket.

Inspect timing belt tensioner.
Jumped timing / belt Check for burn / loose rubber particle on the bottom of the timing belt cover. Recheck timing marks / dots and make sure it's line up correctly.
You should change the water pump and T-belt at the same time. Check the service record for the last water pump change. Spin the water pump and check for free movement and leak.
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After everything are check out then open the valve cover to do a valve adjustment. You should do valve adjustment every year or 12-18,000 miles.

Monitor for oil leaks from rear main seal,front seal and valve cover.

Check for white smoke at the tailpipe after 10-15 minutes of warm up time to rule out head gasket damage.
check for cross mix of oil and coolant.
TDI should go well over 200,000 miles before major over-haul.

Hi, you mentioned timing belt looks ok, but did you check the timing marks? Could the belt have slipped a couple of teeth and maybe the valve timing is off a bit?

TIMING BELT SLIPPED.CHECK WITH MECHANIC SEE IF HE REPLACED TIMING BELT TENSIONER IF NOT.NEED REPLACING.IF MECHANIC REPLACED TIMING BELT FORGOT TO TIGHTEN IT.OR DIDNT TIGHTEN IT ENOUGH CAUSING TIMING BELT SLIP ENOUGH TO THROW OFF THE INJECTION PUMP TIMING.WHICH WILL LOW POWER PROBLEM.TAKE CAR BACK TO SHOP.TELL MECHANIC TIMING BELT SLIP TIME.NO POWER CAR MAKING TERRIBLE NOISE.HE SHOULD FIX NOT COST YOU A DIME.

It is very hard to say what is causing the lack of power. But I would suggest checking all of the belts. Something could have locked up causing the belts to squeal and robbing power from the engine. If the water pump locked up then it would squeal and cause lack of power. Make sure that everything turns freely besides the crankshaft. If something is froze up it will make the belt very hard to turn and won't let the engine build horsepower.