another oil consumption question

[HopskinsS4]

I have a 2005 s4 and it is burning close to a quart every 500 miles. the car has full straight pipes with no cats, it smokes only when decelerating. I replaced the PCV and that didn't fix it. I also checked the compression and every cylinder is right at 150. Does anybody have any recommendations to fix my problem?

[jmcS4]

Valve stem seals and/or guides

[HopskinsS4]

im assuming theres no way to tell if thats my exact problem?

[jakeoboy67]

i'd borescope the cylinders, even if your compression number are not that bad

have checked for oil leaks ? that could add to the consumption

burning oil only on deceleration is usually caused by bad valve stem seals.

[HopskinsS4]

how bad of a job is replacing valve stem seals?

[jakeoboy67]

how bad of a job is replacing valve stem seals?

it requires removal of both cylinder heads, it's an engine out job

[MIRKA_S4]

+1 on the borescope. Dealer only charged me an hour labor to tell me that i have bad cylinder wall scoring. Gonna drive it until i dont feel like putting oil in it anymore, than get a new motor, and not a 4.2. My car has catless downpipes like yours and it started out fine, no smoking. Now it smokes all the time. What type of oil are you running?

[2004B6S4]

how bad of a job is replacing valve stem seals?

it requires removal of both cylinder heads, it's an engine out job

it actually can be done without removing the engine or heads, but you gotta remove the cams which means removing the upper timing covers. still a huge job

[HopskinsS4]

im running 5w-40 rotella t6

[jmcS4]

it actually can be done without removing the engine or heads, but you gotta remove the cams which means removing the upper timing covers. still a huge job

also requires buying close to a grand is special tools, cheaper and safer to do it engine out.

[lettuce]

also requires buying close to a grand is special tools, cheaper and safer to do it engine out.

Can't be much different than the 2.0t, can it? Just have to do everything twice. Unless the aft-mounted chain makes it that much more of a pain in the ass. Tools and seals could probably be bought for around $100 total.

http://www.audizine.com/forum/showth...1#post11465793

[jmcS4]

Can't be much different than the 2.0t, can it? Just have to do everything twice. Unless the aft-mounted chain makes it that much more of a pain in the ass. Tools and seals could probably be bought for around $100 total.

well if you drop a valve you have to remove the chains, and thats no fun if you didn't plan on it

[lettuce]

well if you drop a valve you have to remove the chains, and thats no fun if you didn't plan on it

That's true, but there are a few things you can do to avoid that. One thing you can do is hook up an air compressor hose to your spark plug hole to pressurize your cylinder enough to keep it up. You can further minimize risk using this method by working with the piston at TDC so that even if it does fall, it won't fall so far that you can't just pull it back up. Or for a more low tech method you could just feed a few feet of thick rope into your combustion chamber through the spark plug hole while the piston is at BDC and then turn the crank by hand to raise the piston until the rope is compressed enough to hold everything up.

[2004B6S4]

the tools are expensive and that's probably the biggest issue with doing this. I know JimmyBones has the tools though, he did a writeup over on audirevolution showing how they're used. you could send him a pm and see if he'll rent them out

[QIKRNU]

Or for a more low tech method you could just feed a few feet of thick rope into your combustion chamber through the spark plug hole while the piston is at BDC and then turn the crank by hand to raise the piston until the rope is compressed enough to hold everything up.

This will work as long as you don't get a kink in the rope that prevents you from pulling it out.

[JimmyBones]

It would be a good idea to drive the car until it is hot and then park it in a place where you can work on it. Let it sit overnight. Then in the morning pull the intake manifold off to check for oil pooling in the intake ports by the valves. I had leaking valve stem seals that would cause blue smoke on warm starts like when out running errands with a lot of stops where I had to drive the car a bit, shut it off for a few minutes while I got stuff from a store, then start it back up, drive somewhere else, and repeat. After a while it would blow blue smoke on the first cold start in the morning and on deceleration while on the highway.

the tools are expensive and that's probably the biggest issue with doing this. I know JimmyBones has the tools though, he did a writeup over on audirevolution showing how they're used. you could send him a pm and see if he'll rent them out

I thought that my ears were burning for some reason. Yep, what you said is right.

By the way, to use the tool set the cams and timing chains for the cams have to come off so it is only a few more steps to pull the heads off at that point. Like taking the downpipes off and loosening the head bolts.