change your oil.

im pretty sure everything else has been covered.

 

You can remove the valve cover and get a good look at top end of the engine. If it's pretty clean, that's a good indicator that the oil/filter has been kept changed. Usually somebody that's good about changing oil regularly is also good about general maintenance. if your engine is clean, there's really no need to change out an oil pump.

As noted above, the M1 0w-40 and Syntec 5w-40 are good oil choices and conform to the VW/Audi spec 502.
If it's got sludge, check out www.bobistheoilguy.com and look in the additives forum, do a search for Auto-Rx. Excellent stuff for gently cleaning out a grimy engine, not a snake oil. The worst thing you could do is use a fast engine flush - they are heavy on solvent and can loosen chunks of crud - then you really would need another oil pump.

The ECS timing belt kit is very good - has everything you need to do a complete job, just get 2 liters of the Pentosin coolant as well.

I'd second that comment about getting an Audi mechanic to check the car out as well.

 

I disagree somewhat. The 1.8T failure mechanism is gradual clogging of the oil pump inlet screen by oil sludge/coke. Sharky, a VW tech on PassatWorld.com, reports that he has seen 1.8Ts which looked clean on top, but which had horribly sludged oil pumps. Of course, if the top looks bad, find a different car to buy!

 

Good point. I probably should have said that in most cases, valve assemblies and top ends are good indicators of the oil change intervals, but you are right on the 1.8T. I would think that if that's the case, oil pressure might fluctuate enough to raise questions, like getting a low oil pressure light at hot idle.
I'm paranoid about the sludge issue on these cars. For me, the synthetic oil, big Mahle/Mann filter and no longer than 4500 mile oil change intervals are a must.

 

I just had the sludge diagnoised at the dealership. My red oil light came on about 3 weeks ago then went off, then came on again last week. Apparently you really can't tell the extent of the sludge until you drop the oil pan. Then you have to replace all your PVC system, lines and oil pump.

The oil changes at 4500 mile intervals is key, but if the sludge occured early on in the engine's life, its probably still there. I was going to do the Auto-RX thing that blackA4 recommended but im trying to get Audi to cover the sludge flush. Auto-RX is only is around $100-129 for a engine flush. This is definately something i'd consider if you are worried.