just finished a 4.5k roadtrip, gawd I'm burning a lot of oil

[norcal]

used up 8 quarts on this trip, got so bad that the rear end has a nice coating of oil on it and my tips are so black you'd think I had them finished in matte black ... during mountain ascents, I'd be blowing a lot of oil smoke out the tailpipes

with 120k, my engine is dying

time to park it, get a beater, and begin the long and expensive process of repairing this mess. I plan on adding headers and a stg III clutch while I've got it all apart

the fucked up thing is I think I caused this issue. Back when I did the intake spacers a whole mess of sand dropped down into the valves, you might remember my thread I created this past Feb ('11) asking what I should do. I ended up sucking/blowing as much out as I could be what was done, was done. I'm sure there was too much sand in there and next thing I know I had scored cylinders.

Gonna get a leak down and compression test done soon but I'm sure the results will be low compression in several cylinders, most likely somewhere bank 1.

Oh well, it's gonna be badass when I'm done. At least this thing has been from vermont to texas, and from texas to ca and back twice. Not to mention all over west texas, oklahoma and arkansas

[Joey]

Damn, sorry to hear Justin. A good possibility that a little bit of sand could have scored the walls.

At least you have a positive attitude toward the whole thing. With some time and work you are certainly going to make that avant in a mean car!

How was the road trip otherwise? Looks like the pup had a good time

[norcal]

It was a really great trip. Did have a little bit of a serp belt snafu in vegas but not a big deal. Hit quite a bit of snow through AZ which was fun. bonzai'd it home, covered about 1800 miles in about 32 hours total time, which was about 25 hours actual driving.

Such an amazing road trip vehicle but fuck I wish we had an autobahn-like highway system. I blink my eye sometimes and I'm going a 100. Another successful mission with no radar detector and no speeding tickets. 2 warnings though

[dmaxben]

With that much oil actually making it to the tailpipes (as opposed to it just being completely burned) I'd almost wager a guess that the problem is more valve stem seals than actual scored cylinder walls....

I highly doubt your intake-spacer job was what ruined it.

[norcal]

hmmm, really? My only experience with worn rings (which I imagine being similar in behavior to scored walls) was on an air-cooled VW and it was very similar in terms of smoking and such. I know we're talking major apples/oranges here but still.

[dmaxben]

Its hard to say for sure...but heres something you can try.

Let the car sit for a day or two, clean the exhaust tips with a rag or something (so theres no wet oil residue). Then do a cold-startup of the car, let it run for a minute, and see if theres any wet oil on the exhaust pipes/tips. Or you could pull the intake manifold off and have a look at the valves for any oil sitting on top of the valves.

And then of course do the compression test, that will tell you for sure...

I miss my B6 S4 every day, but sometimes when I really think about it, the unfortunate fact of it taking a slug of water (and insurance subsequently totaling it and giving me almost 7k more than it would have been worth with a good engine) might have been a blessing in disguise. But then again, mine had 110k miles and would only burn less than a quart of oil every 5k or so...

Im pretty convinced that how the car was treated early on in life (and how it was driven before the engine was warmed up) and maintenance plays a role in long-term oil consumption/ring/cylinder wall wear on the timing-chain 4.2's. I was the second owner of my car, and the original owner was a lawyer who was in his late 60's, so I think its safe to say the car was driven more easily than most S4's especially when cold...and I know the car was well taken care of because the original owner literally saved every single oil change receipt. And like I said, at 110k miles, my S4 burned basically no oil in comparison to other 4.2 S4's of similar age/mileage.

[norcal]

alright guys, just had my compression, leak down and camera inspection of the combustion chambers ...

there is light cylinder wall scoring, nothing crazy that would cause oil consumption. my compression is consistent across all cylinders but on the low side (150-160, where 140 is the audi recommended low).

oil consumption is coming from my valve guide seals on bank 1, likely caused by too much oil (aka oil sludge) which I guess is odd because I have all the service history for this s4 since new and it was regularly serviced at the dealership per recommended intervals

they are saying the scored cylinders is likely due to oil deposits on the oil scraper ring (side effect of the valve seal blow by most likely)

valve seals can be replaced with engine in car, valve guides could also be bad but hard to say until torn down, valve guide replacement requires head removal, which would obviously encourage cylinder honing to remove scoring, which would obviously encourage entire timing chain component replacement, which would of course encourage stg III clutch and headers ...

oh my!

1. win lottery
2. major avant repairs and upgrades
3. best avant evar

[dmaxben]

oil consumption is coming from my valve guide seals on bank 1,

hmmm just as I suspected...


Good to hear that compression is still pretty decent...but you cant just "hone" the BHF cylinders, as far as I know due to the alusil machining/honing process. You'll most likely either have to just leave then alone or find another engine....

[norcal]

I was quoted $5k to R+R the engine, remove the heads, replace the valve seals and guides, and replace all worn timing components as needed. I was assured that the cylinders most certainly could be honed, depending of course on the extent of scoring, but the machine shop did not say anything like "no these cylinders can never be honed". Either way, it's a minor concern at this point compared to the more important valve issues and I could likely roll another 100k and see no major increase in cylinder scoring as long as my oil is changed regularly.

At this point I'm thinking of passing on the headers due to the increased cost and just doing the stg III clutch. Will have to see where my finances are when it's time to put her under the knife. I've got a hefty property tax bill coming up and then a fucking mountain of taxes due come April so I'm a little nervous about that.

[littleredwagen]

FYI these valve guides can be tricky. Take them to a shop that has done them before.

[norcal]

I think they were gonna take the heads to a machine shop, not sure. The shop owner races pretty seriously and seems to know his shit so I trust 'em.

[dparm]

Why do you think its sludge? Remove the valve covers and inspect. I doubt you have that if you've run synthetic oil.

[norcal]

it's what they told me, they said the oil scraper likely caused the minor scoring due to the excessive oil allowed in via the bad valve seals and the bad valve seals were likely caused by sludge blowing out the seals

[dparm]

Sludging doesn't really happen these days unless the PCV is totally FUBAR, or you're using some shit oil (which is nearly impossible to find, short of running the no-name gas station stuff). I have seen sludging on motors that didn't get their oil changed for like 25,000 miles though.

[norcal]

hasn't sludging been a problem for VAG for a while now? 1.8T is dated but that engine is a fine example

I have all the service history for my car, regularly serviced at the dealership up to when I bought it at 80k. I've been religious as well. I did replace the PCV this spring but the old one seemed perfectly fine.

[littleredwagen]

hasn't sludging been a problem for VAG for a while now? 1.8T is dated but that engine is a fine example

I have all the service history for my car, regularly serviced at the dealership up to when I bought it at 80k. I've been religious as well. I did replace the PCV this spring but the old one seemed perfectly fine.

1.8t were sludging up because of the oil pickup and using non-synthetic motor oil. The switch synthetic pretty much fixed it from my understanding

[norcal]

1.8t were sludging up because of the oil pickup and using non-synthetic motor oil. The switch synthetic pretty much fixed it from my understanding

VAG also decreased the change interval from 10k to 5k iirc

[dparm]

1.8t were sludging up because of the oil pickup and using non-synthetic motor oil. The switch synthetic pretty much fixed it from my understanding

Correct. It was partially a design issue but also an oil change interval/quality issue.

The only times I see sludge on modern vehicles is if (A) a really lousy oil was used for a really long time or (B) a synthetic oil was basically never changed. Technically you could get contaminants in the oil to sludge it up but that's quite difficult without other problems rearing their head first.

[SpeedETC]

valve seals can be replaced with engine in car

In order to replace the valve seals you need to pull the cams which means removal of the chains. I am not saying that it is not possible, but I cannot see how you can replace the seals without pulling the engine.

[Joey]

Sludging doesn't really happen these days unless the PCV is totally FUBAR, or you're using some shit oil (which is nearly impossible to find, short of running the no-name gas station stuff). I have seen sludging on motors that didn't get their oil changed for like 25,000 miles though.

Last year we picked up a replacement motor for my brothers E46. I believe it had 75K miles on it and must have only had the oil changed twice its whole life. The amount of sludge in that thing was incredible. Maybe i can dig up some pictures for reference.