I have a L200 2.5 with a turbo that seems to work for the first couple of minutes when first started and the power seems to get worse the longer you drive it. I pull a caravan and its a nightmare I can not get the jeep past 2000 revs when towing. I was told it could be over turbo, have you any ideas what I can check or try. Regards Chris

You MUST have the electronic engine control module scanned for fault codes to even begin to diagnose the cause of this.

Sounds like there is a cylinder that is miss firing. Could be a plug or plug wire.

READ THIS (happy ending so far...):
audi a4 2L turbo quattro, manual transmission with 98,000 KM. Perfect conditions, no oil leaks whatsoever.

Left the car off for two weeks in very cold weather (-10C down to -25C). When I restarted, it started immediately but with heavy rattling noise due to camshaft adjuster not getting enough oil pressure. After 3 minutes of warming up (outside temp.: -12C) at very low rpm (below 2,000rpm), I start moving the car. Still hearing heavy rattle noise. As soon as I pass 2,000 rpm, I get a scary red warning, low oil pressure. Turn off the engine immediately. In 1 minute, I re-start the car and the engine lights check ok, so I drive in first gear super slow (1,200rpm) hearing the same rattling noise. After another minute, finally the noise all the sudden disappears and the car starts running just fine.

Called Audi dealer and they told me that in extreme weather conditions, I should warm the engine for 10-15 minutes if necessary before start moving.
Take away: luckily, I didn't screw up the engine since I was using it at extremely low rpm (easy to do with clutch and manual transmission) until the oil reached full pressure. I am pretty sure now that the problem was leaving the car off for such a long time in freezing weather. All the oil flows back to the bottom, and when I restarted it, the cold oil with high viscosity took a long time to reach all the parts of the engine, specially the camshaft adjusters that are actuated by using oil pressure. Next day, the car started at -9C perfectly without making any noise (as usual). Basically, the longer you leave your audi in cold weather, the longer you might hear the rattling noise until the oil reach full pressure inside the engine. My car took 6 minutes to fix it after couple of weeks in cold weather. This makes sense to me; in fact, in the past I only heard the rattling noise after leaving the car off for a couple of days in the winter.
So far, this has had an happy ending....

A new turbo charger is about $340, but you can buy the bearings and seals and rebuilt if yourself for about $100
http://turbosandparts.com/
It is not hard, and it does not take long to do.

I normally do not bother with synthetic, but with a turbo charger, it might be worth it. What really seems to ruin turbo chargers the most is not letting them cool off before parking.
Once you turn off the engine, there is no longer any cooling, so the build up heat will burn up the oil and seals.
Run the engine for at least 5 minutes below turbo levels, before shutting down the engine.

A bearing going bad. Do you follow turbo shut down procedures? If you don't have time to do this then my suggestion is installing a turbo timer to do this automatically. When you drive the car specially a high speed and need to shut down the engine is the worse thing you can do to your turbo. The impeller spins double the speed of sound and takes quite a while to slow down specially when you shut down the engine. At the same time it is shut down, oil pressure is no longer provided by the oil pump and cooking from extremely hot turbo assembly. The end product is oil carbonizing and clogging moving parts. The term is called coking. A turbo timer will keep your engine running when you remove the key from ignition and lock the vehicle for a programmable amount of time. This will help the turbo to spin dow while lowering the temperature critical for a longer servie life of your turbo charger.

the turbo is a good start remove and check for excessive play on turbine/compressor sharft, one way to check is to press down on the shaft on the compressor end (silver side) and turn wheel,if making contact with housing then you have worn bearings causing wheel to drag slow down it's speed caursing it not to work,also check the condition of both wheels, compressor and turbine if pitted or worn replace unit, if cost is a factor then a reman or a good used unit will work,

common problem with VNT turbo's fitted to audi's is sooting up of the variable nozzles of the turbo. this causes the the actuating ring inside the turbo to jam, the engine managment senses this and goes to emergency running mode, ie low power. You can clean turbo VNT housing if your a bit handy with the spanners but this involves removing unit from the car and cleaning housing, actuator ring and vanes on the exhaust side of the turbo with scotchbrite. You dont have to dismantle the impellor but you do still have to keep every thing really clean. Another cause of power loss is the air flow meter so you may want to check that out before taking your motor to bits.

In year /model 87, code 23 was oxygen sensor stuck in full rich position. I'd be tempted to try a new one.

TRY ANOTHER FUEL PUMP AND FUEL FILTHER THESE PUMPS ARE FUNNY ON VOLVOS HAD SAME PROBLEM ON 850 TURBO AND SURE ENOUGG IT WAS THE PUMP

these jeeps must be rubbish save yourself a couple of grand and get a new car like a landrover or a little car like a vw golf or a Cadillac