B7 S4 Buying Advice

[tbauminla]

Hello Audizine,
This is my first post, so please bear with me. I recently test drove a 2006 B7 S4 and am seriously considering buying it. The car is completely stock and seems to have been taken care of pretty well. But, given the fact that this is a B7, I must ask about the timing chain. The car has 123k miles on it and the current owner has told me that Audi has never warned him about any problems. When I drove it I did hear a slight clicking noise, but I couldn't identify if it was from the timing chain or some other part of the engine. I'm having the car looked out by Audi after the weekend to do a full pre-purchase inspection, but I want to know how seriously I should be worried about the timing chain. I've read everything from "very few of these cars will need tensioner replacements" to "every B6/B7 should have the parts replaced after 100k miles."

Can someone clarify if this is really an issue worth worrying about or if I'm just freaking myself out. Thanks!

[VinnysS4]

There has been a lot of hype on the chain service with the 4.2L s4 engine. The hype is for a valid reason, but there are plenty of people with higher mileage then that one without having the service done to it. It is a known fact that the Guide that fails more often then the others is made of plastic. These engines have loud valve trains and the clicking you heard could be from that, or any other number of things. Definately get it looked at...however even the best mechanics wont be able to tell you if one of the guides is going to fail soon. Listen to the engine at cold start up..do you hear a rattle? what about warm start up? The oil check valves can rattle a little on this engine upon start up and that is often mistaken for chain rattle. Get the pre-purchase inspection. If you plan on keeping the car a long time, you might want to set aside some money for the service just incase it needs it in your ownership. However, if you plan on only having the car for a little bit, then just buy it, drive it, and enjoy it. Does the owner have the service records?

[tbauminla]

Does the owner have the service records?

The owner has all of the service records and while I looked through them I didn't find anything other than oil changes and power steering components that needed replacing (which he told me about). Hopefully if there's anything major the Audi mechanics will catch it before I purchase.

[badger.]

The oil check valves can rattle a little on this engine upon start up and that is often mistaken for chain rattle.

Just to clarify, The check valves themselves don't rattle. It is still chain rattle. They valves stick (fail) allowing oil to drain down rather than staying up and available for lubrication on startup. This is just one potential cause of the "startup rattle". No good way to tell if it is a busted guide or stuck check valve if you do. And pretty sure you could still get rattle occasionally even with good valves and guides

[DasShane]

These are great cars but they do have quirks. But the more time you spend with them you get use to and understand it all. I have 157k miles on my 07 and it still runs great. Minus the leaky valley pan gasket I just fixed. The biggest thing I'd look for is proper maintenance records and making sure everything was done right. The car does whine and make weird noises sometimes but it's pretty normal. The whine is the power steering because it's gear driven from the back of the engine.

Sent from my SM-G900V using Tapatalk