craig.wilson1

I have a 2012 Audi Q5 2.0 TFSI with 96K miles. It has been relatively trouble free, but I suspect that it might be on the verge of the high oil consumption issue. I have just started my 1st "official" oil consumption test, but suspect from recent history that it is using 1 qt every 800-1000 miles. I just took it in for an inspection and the mechanics found active oil leaks from the timing chain covers and the valve cover, although I doubt this fully explains the high oil consumption. They also recommended a timing chain replacement based on mileage. I've done some research and found that timing chain stretch can be estimated using a VCDS scan tool. I did that yesterday and the cam adaptation value was -3.05, which I believe is just into the "warning zone"? I've also read concerns about the tensioner. So, I'm faced with some repairs that if done by a dealer likely approaches the $ value of what I could sell the vehicle for as-is. I have some mechanical ability and conservatively rate my abilities as 6.5/10. Based on some of the videos I've seen, I'm pretty comfortable taking on the timing chain replacement, but am not sure about piston/ring replacement. Apart from the engine issues, the car is in great shape, new tires, good brakes, no rust. So I'm thinking of spending the minimum needed to get another 30k-40k miles out of the vehicle. Would really appreciate some input on the proposed plans below:
- Replace the timing chain tensioner only. This would save some money on parts, but I'd run the risk of engine damage due to excessive chain stretch - given the -3.05 value, can I get another 40k miles?
- Replace the timing chain, guides and tensioner - More $ for parts, but I have the timing chain covers off anyway if I'm doing the tensioner.
- Water Pump - If it hasn't been replaced, is this a recommended pre-emptive job?
- Valve Cover Leak - I'm thinking of not doing anything there unless the leakage gets out of hand - I'm assuming that there is no risk of damage to anything by not doing this
- Pistons/Rings - I'm thinking of waiting on this one until I know exactly how much oil I'm burning. Although I've read about some concerns that if left alone, cylinder wall scoring can occur. Also, looking for some candid feedback on whether this is a DIY project.
Hoping for some advice.

craig.wilson1

Hoping there is someone out there that can provide some input...

S4'ed

Buy a Toyota.....

I would try some BG EPR oil flush, do a back-to-back (double) flush, see if your oil consumption improves. If it does get better, do another EPR cleaning at every oil change, till your consumption is acceptable. Follow the directions on the can.

If this reduces your oil consumption, then you should replace the chain, all the guides, and the tensioner. Make sure you get the latest timing chain design (best to buy from VW/Audi dealer), as most cheaper vendors sell the older, less durable chain.

Also, replace the PCV/Pressure Regulator unit, again with the latest version, from a VW/Audi dealer. There are lots of much cheaper older design and knock-off manufacturers selling new units. The only OEM manufacturer is Hengst.

Concerning the waterpump, a valve cover that leaks oil onto the top flange of the waterpump can cause the waterpump-to-block gasket to swell, which then cracks the plastic pump body. You should fix the valve cover, and then, only replace the waterpump if it starts to leak. Note that the valve cover gasket is just a liquid sealant, there is no actual gasket. There is a special procedure to follow when removing the valve cover ("Top engine cover"), as the cover is not just a cover, it is also the upper halves of the camshaft bearings. Doing this while doing the chain replacement is a good opportunity, as the cams can "jump time" when the cover is removed.

If you need to replace the pistons/rings, to fix the oil consumption issue, it can be DIY, but the engine needs to be removed from the vehicle, disconnecting it from the transmission, for access to remove the pistons. This job can't be done with the engine in the car.

craig.wilson1

Thanks for the information, especially the heads up on how the valve cover leak can lead to a water pump replacement. I hadn't heard of the BG EPR product either, will definitely look into that.

craig.wilson1

I did the EPR Flush and then jumped into the timing chain replacement. I opted to remove the front carrier from the car to get full access to the front of the engine. There is an excellent Youtube video from FCP Euro that goes through all the steps of removing the bumper, removing the carrier, replacing the timing chains and putting things back together - I also used the Audi ErWin manuals for additional details. Everything is back together and the car is running just as it was before doing the work (very well). Although the timing chain replacement can be done without removing the front carrier, I would recommend that anyone doing this work for the 1st time remove the carrier to get full unrestricted access and direct line-of-sight to everything. I am now waiting to see if my oil consumption issue improves after the EPR flush...

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