2011 VW GTI issues

Sorry for the long post but......

So for the last year I have a 2011 GTI with the 6spd manual with 140k. About 6 or so months ago it started throwing a code for the cam sensor and the timing chain rattled on start up. This is a known issue so I parked it. 

Fast forward to yesterday I finally finished installing a new timing chain tensioner. It took 3 days of off and on work as some one(probably a dealer as it was a recall/warranty issue) had done the job before and VW uses small torx head screws to mount the lower cover. Two stripped so I spent hours getting them out and a motor mount bolt stripped the aluminum motor mount bracket threads out. Had a machine shop fix that. Also one of the timing chain guide bolts was sitting in a valley of the lower cover as it either backed out or was never installed. 

I got it all back together, cleared the code and the chain rattle and code were gone.

i got 1/4 mile down the road when the ABS, airbag, and the  tire pressure lights came on and stayed on. It also decided to run rough/miss at idle only. It pulls through the rev range clean thou. 

When I bought the car I replaced the in tank fuel pump, coils, plugs, and filters with VW stuff and had a few thousand miles on them before the timing chain issue. 

So ideas? It’s currently pouring out so I’m just trying to get a game plan. I plan on trickle charging the battery and checking all electrical connections. 

Accessory belt is loose or came off causing low voltage? 

I dont  think so as I popped the hood to check for oil leaks and believe I still saw it as I was thinking a low voltage issue. I replaced it with a new one as it has to come off for the timing chain tensioner job. Also it’s got a tensioner which seemed fine.

I’ll double check if the rain lets up. 

Are the ABS/TPMS/airbag on the same fuse? Only thing I can think of that would easily connect those 3 and I am a big fan of single points of failure. 

Do you have Torque and an OBD reader? Odds are good you have some other symptoms if you can pull the full codes. 

Rough idle can be a symptom of the oil filler cap not sealing properly. Start the car and take that off, if the idle gets rougher then your problem is probably somewhere else. (Also a good way to help diagnose PCV problems) At least on the FSI engines, the oil filler cap needs to seal for the engine to run smoothly, as it works in conjunction with the PCV. I'm not sure how, I didn't read that far, but I do know it works. 

Is the battery properly charged or weak after sitting for so long?

I would start by charging the battery and make sure its good. Reset all codes by removing the battery and seeing if they pop up again. 

Serpentine belt is still on and good, I just put the battery on a trickle charger as I won’t be able to mess with it till Saturday. 

I did some google research which some forums were saying the wheel speed/ABS wheel sensors might be gummed up from sitting all winter and all those system are interconnected. 

I’m hoping it’s all done to a low/crapped out battery thou. 

rattfink81 said:

Serpentine belt is still on and good, I just put the battery on a trickle charger as I won’t be able to mess with it till Saturday. 

I did some google research which some forums were saying the wheel speed/ABS wheel sensors might be gummed up from sitting all winter and all those system are interconnected. 

I’m hoping it’s all done to a low/crapped out battery thou. 

Different manufacturer; but, when I was a Honda tech, vehicles with drum brakes and wheel speed/abs sensors always got gummed up and caused similar fault codes. Try cleaning them out to see if it helps. Not sure of their location on that generation of GTI but they shouldn't be to hard to get to once the wheel is off. 

Figured I’d finally update this cause I hate threads with no answers.

i bought a OBD11 which is a device that goes in the obd port and connects via Bluetooth to your phone and you use there app. It’s like a cheaper easy to use vagcom.

So I used to check all the systems and I’m pretty sure the timing chain is stretched beyond spec and the ecu can only compensate so much which is causing misfires. It’s a another know issue with mk6 TSI engines.  I’ve been daily’ing anyway cause I don’t have the $1500 and weekend to do it currently. I know I’m playing with Fire.

second issue I believe the ABS module is toast, another known issue as I get all sorts of wheel speed errors and such but all the sensors are good and give the same readings per the live feed.

So yeah VW issues.

I'm confused.  The car has over 140K miles on it, and when you did the tensioner and guides you didn't put a new chain in?  I would think that would be standard procedure, but maybe not?  Or am I not understanding correctly?

No I didn’t replace the timing chain and rails, everything I had read on the forums said it was a non issue(seems that is no longer the case as it’s become a documented issue) and I only planned on keeping the car for 2 or 3 years and drive maybe 10k a year tops. The guides looked in good order when I had it apart.  The parts aren’t cheap and the timing chain tensioner seems to be pretty much a maintenance item on these so I rolled the dice and lost.

I’ve only really have owned early 90’s and earlier American 6 and 8 cylinder cars/trucks, a bunch of 70’s 80’s euro beaters and the wife’s had a few subies so  expensive timing chain setups is new to me.