
Originally Posted by
fastboatster
it's a bit strange we still don't have any kind of "what to look for when buying..." sticky thread. This thread sounds a bit different from what I heard a year ago when all I could hear was that 3.0T is infallible and all dsg problems can be fixed with mechatronic pcb kit, but anyways. Let's talk about some possible issues:
Engine timing chain rattle. If timing chains in the back of the engine rattle for more than 3 sec on cold startup, Audi says it will need revised upper timing chain tensioners. Somewhat expensive to do.
Secondary air passages carbon build up - somewhat rare, also will cost you a lot to get them cleaned up. I forgot DTC codes for them, but you can search for secondary air injection problems.
Melted/breaking down cats - if you don't have a visual inspection during emission testing where you live, then it's not a big problem since the old cats can be cut and removed from the car. If you do have a visual inspection then it's a bigger problem as cat replacement requires lowering engine and trans along with subframe. Although there might be a better method.
DSG - yes, mechatronic problems, yes, sometimes they can be fixed with that PCB kit you posted but not always the case. Clutch can wear out at high miles, too. One issue I want to highlight because I had it, saw it popping up a few times on this forum and saw a few CL cars sold with this issue is gear selector lever sensor malfunction. The car won't know if it's in P, D or R and will be rendered completely undriveable. Unlike on most of the normal cars, it's buried inside the trans and will require either a new trans or getting the old one completely disassembled. Not too many shops will do this for you, and pulling DSG out yourself is not recommended unless you have a lift, otherwise you can't pull it from under the car and it's a 300lbs monster which can easily kill/maim you if you drop it. 10 hrs labor to remove the trans and a few more to get that sucker replaced. Unless the sensor is completely dead, this issue will usually not manifest itself until the gear oil in the back of the trans gets hot which might require a few miles of spirited driving (one person drove the car from a dealer on a highway for a few hours(!!!) and didn't noticed it until they started to drive in stop and go traffic). Note that this trans has 2 chambers, one with mech and clutch and another with all the gears. Of course, the oil in the gear chamber is "lifetime" and almost never changed since it's not recommended by Awdi and that's where that sensor lives.
Anyways, due diligence is required when buying a B8 S4 (and maybe B8.5), unlike on many competitor cars, some repairs require twice the labor time and some jobs are a LOT more difficult to DIY (transmission). How many miles does that car have? What year is it? 2010 might not have launch control and will have trans oil filter integrated into one of the trans lines, 400$ to replace if you need to.
Thanks for all the info!
I'm willing to tackle most of those issues, though the shift lever issue would probably drive me to manual swap if it ever happened. The car is a 2014 with 80k miles.
Ive looked up the process for replacing the water pump, thermostat and PCV, and im confident i can handle that considering i did the timing belt, water pump etc and engine mounts on my c5 a6. I would consider this to be preventative maint at the mileage the car has.
As of right now: what i am looking for is timing chain rattle at the back of the cylinder heads, any sign of coolant leak, and im paying extra attention to how she shifts. As to finding a car with the right service history. Id love to find one with Audi done maint every 5k miles but honestly, the selection is so limited i dont think i have that choice. My hope is that the 8.5 resolved some of the issues with the 8.
I plan to mod the car pretty extensively, stage 2+, coilovers, bbk, e40, bracing etc. (down the road) so i plan to do as much as i can to 1. start off with a good specimen and 2 to prevent any issues i can with maint.
I considered a 335i, which is cheaper to buy, but it didnt excite me like the s4.
Bookmarks