KneeDeep

I'm driving an '02 Tip S4 Avant with ~105k miles and am coming to a decision point about whether to sell (shudder) or save it a by spending to fix problems related to/caused by the intercoolers filling with oil
- replace the turbos + lines (one of the oil seals is leaking)
- replace a leaking cam seal
- replace one of the cats @ related O2 sensors

I'd like to drive the car another 100k miles and am wondering, if I elect to have the issues above fixed by my mechanic, what else should be replaced while the whole thing is opened up. The car is totally stock and I'm more interested in durability than upgrading for more power. Any and all suggestions welcome.

Already replaced are:
- Aux water pump @40k
- Coolant temp sensor @50k
- Turbo bypass valves @60k
- Timing belt, tensioner, water pump, thermostat @75k
- Breather hose, crankcase vent valve, intake, valley pan gasket, fuel injector seals, vacuum line, multi-rib belt @ 95k

rktskicar

If you do alot of WOT can get oil in your intercoolers. Just drain it periodically. When I had my K04s installed, the guy told me I had like a quart of oil in my intercoolers. This was at 83K miles.

My K03's were fine by the way when removed.

Bruce

bingS4

Are you sure about those leaks? As rktskicar said, some oil in the ICs is normal. If you want to keep them cleaner, look into installing an oil catch can.

KneeDeep

I def know there's a cam seal leak because of the odor in the cabin, but that wouldn't douse the cat with oil.

It's my mechanic's hunch on the turbo seal leak. He found an iATN post that mentioned the 2.7 biturbos leak oil excessively and then kill the cats. The check engine pops up every 1-2k miles and the VAG codes keep saying O2/Cat. Issue #1 is to take care of whatever is dousing the cats with oil, cause I'm not sure it's going to pass inspection.

I rarely put this thing WOT, usually only once a month to do an italian tune up to blow out anything that's accumulated in the turbo pipes, etc.

bingS4

How fast is the oil level going down? Any blue smoke out the tailpipe? Those are also indicators of oil going into the exhaust.

If you do end up pulling the engine, I'd go ahead and replace the K03 turbos with K04s for better dependability and the possibility of upgrading down the line for more power if you so choose. If your mechanic will do it, I'd also suggest replacing your stock downpipes with a set of piggie pipes from VAST. That's an inexpensive way to take care of replacing your cats as well as opening them up for more power options down the line as well.

I can't suggest anything else since it looks like you already had a lot of stuff replaced. If your valve cover seals are seeping, you might as well have those replaced while you're at it.

Good luck!

01A6Turbo

At 105k miles, if your O2's were never changed, I'd suggest changing them. You can STFA for my write up on the pre-cats for the 2.7T A6. The post-cats are even easier - just from underneath the car. If you get a mech to do the job - you're looking at least $400 for the pre's - they truly are a PITA. As far as your cat codes - please inform us of the actually code number itself. If it's P0421 (Warm up catalyst below threshold) you may just be due for a *FREE* reflash of your ECU due to a recall back in 2005 from Audi TSB (http://www.allworldauto.com/tsbs/NHT...tin_79227.html)

So don't sweat her and waive g'bye just yet lol

As far as the cam seals leaking - you can buy new ones for $5/pc x 4 seals and new inner/outter valve cover gaskets for a good price also - it might take you 2-3 hours per side but as long as you have DECENT (notice I didn't say good or excellent) mechanical skills and a Bentley Manual or even the tech archive DIYs/Write-ups - this is another big hunk of change you can save yourself by DIY rather than paying a mech. If you want my honest opinion, the mech that did your TB/WP/T-stat job half assed it and wasn't honest with you. Any dependable audi/vw certified mech knows that at the time of the t-belt job, it is best while 1/2 the front of the car is disassembled to do the cam seals, valve cover gaskets, cam plugs, cam tensioner seals, and check everything else out in the vicinity. Keep this in mind if you keep the car to its next TB job.

As far as the turbos - I agree with the others. If they aren't howling, you aren't losing mass amounts of power, your turbos are probably fine. Although they can go at 60k, 130k or 250k - one can never say. But 105k seems a little premature to me if you take care of yours (full syn oil, let them warm up before/cool down after driving, when was the last time you replaced your diverter valve(s)? (These can help preserve turbo life) - I went with APR's R1 diaphragm based DVs and love them - + lifetime warrantied whereas if you go with OEM 710N's from the 225 TT's you need to replace every 35-40k.

I hope this helped you some...any other questions - feel free to ask us or next time STFA a little better - there is SO much information on these forums available to you at the drop of a dime - but that's what we're all here for - to help other AW'ers in need G'luck!

KneeDeep

This is exactly the kind of advice I was looking for - once the weather warms up I'll have some time to do it myself and skip the mech, but inspection is up this month, so I'm trying to figure out how to use the VAG cable/software and trick the ECU into showing it's clean.

Thanks a lot for the direction here

S4-Richmond

If you only go WOT once a month, then sell it and buy a Prius.

01A6Turbo

^^ *chuckles*

Anyhow, you are not going to "trick" the ECU with VAG-com. VAG is there to reset and erase the codes (DTC's) that the ECU receives from each system of the vehicle. I believe there are 9(?) systems. Every time you reset the codes, you basically wipe the ECU clean and the car needs to go through a drive-cycle in order to relearn all of its values in each system. This is typically done by just daily driving (about 50-100 miles) or can be done in 10-20 miles if you give the car everything it wants. (cold start, 2 min idle, WOT to 60mph, coast, decel (preferrably without braking), full throttle back to 50-55mph, etc. Google "automobile (or ECU) drive cycle."

One reason why the ECU does this, is not only to constantly monitor each system of the vehicle for your safety, but it is also a mechanics way of trying to eliminate those with junkers who JUST cleared their codes before turning into the garage for their state inspections. Their diagnostics and emissions tests will pick up that the codes were just recently cleared almost immediately.

So my advice, get a diagnostics as to what's wrong (or use your VAG-com) and STFA greatly to determine the fixes of your problems. If you absolutely get stuck or have questions, find a thread on the same problem and ask someone from that thread, try and fix your own vehicle the most that you can. IT will literally save you THOUSANDS of dollars. The rest that you can't perform (due to weather, lack of proper tools, or inexperience/skills) then at last resort seek out your indy mech.

Best of luck, and hope this helps!