spijun

Only 2.0TFSI engine has chain ( CDNC, CAEB, CDNB, CHJA , CPMA, CPMB, CHJA, CNCD, CNCB )

2.5 engine not exist in Q5


Timing belt ( toothed belt ) in 2.0TDI ( CAHA, CAHB, CAGA, CAGB, CSUA, CSUB, CNHA )

uberwgn

I think many of the VAG diesels still utilize that rubber timing belt....

motoguy128

2.0T petrol engine.

...The only ones that eat oil like a 2 stroke if you "win" the lottery. Easy to spot by the cloud of oil smoke.

Kris Hansen

I will never understand why people think chains are better than belts. I'd MUCH rather be able to replace a belt every 60k than have to pull the engine and replace thousands of dollars worth of chains and tensioners when they go bad.

JimVonBaden

Agreed, though chains tend to last longer. Most belt driven engines these days are non-interference, so little downside to a belt. (I do not know if the Audi is non-interference.)

Kris Hansen

The chains themselves, sure. But I've seen too many issues with guides and tensioners on the 3.2 and 4.2 engines, as well as the 2.0TSI. At least on the 2.0T it is on the front of the engine.

JimVonBaden

No doubt you are right. I am not that familiar with the Audi engines.

spijun

After 2009 book states for ALL 2.0TDI engines..... 180.000 km = 114.000 miles for toothed belt

Redd

Chain, belt...a lot also depends on the engineering choices that were made. My friend had a 400ci/4bbl Pontiac '69 GTO when it was almost new, and he found out at 40,000 miles that an under-engineered chain mounted in the rear of a high horsepower engine was a very inconvenient and expensive part.

Build it strong enough (costly enough) to take the load, and either one will go the distance. Use a belt and fail to keep it cool, and yes, it will take more damage. But these are all intentional design choices the maker can make. The belt will provide a quieter engine, all else being equal.

motoguy128

Unfortunately there's so little clearance you still need to remove or at least loosen he radiator and most of the front end. It makes a 1 hour job a 4 hour job.