I'm in the process of tearing down the 02 S4 for the 24k service. 'Twas planning on valves, belts, and any flaking rockers to be taken care of.
I noticed with the TBs pulled to the side that it looked like there was oil on top of the valves. I will take a closer look tomorrow to confirm but in the meantime, I'd like some thoughts on why it may be occurring and how to fix it.
Where is your breather connected?
Valve seals
Quote from: EEL on April 07, 2015, 09:37:17 PM
Where is your breather connected?
Stock configuration.
Quote from: ducpainter on April 08, 2015, 03:04:38 AM
Valve seals
Pretty obvious answer. Have you swapped them out on a desmoquattro?
No, but I'd weigh all the circumstances before I jumped to any conclusions about them 'needing' to be replaced.
Did the bike have oil consumption issues last season?
How long did the bike sit to accumulate how much oil on the valves?
Are the seals the type that lock on to the guide, or are they the type that float on the valve stem?
Some oil on the valve stems is not necessarily a bad thing.
Quote from: ducpainter on April 08, 2015, 04:26:53 AM
No, but I'd weigh all the circumstances before I jumped to any conclusions about them 'needing' to be replaced.
Did the bike have oil consumption issues last season?
How long did the bike sit to accumulate how much oil on the valves?
Are the seals the type that lock on to the guide, or are they the type that float on the valve stem?
Some oil on the valve stems is not necessarily a bad thing. DING DING!
Also, are we looking at wet unburnt oil or black residue? Intake or both?
Not sure about the type of seal. They looked locked into place with a small coill around the top.
The bike has been sitting for the winter. About 6 months.
It was last ridden hard for a few hundred miles in the mountains down in WV. I did notice really low oil level when I returned from the trip. I just attributed it to hard riding. The guys riding behind me confirmed no smoke.
I don't have the exhaust off to check those valves. The intake valves have both burnt and wet residue.
This is just me...
if the bike doesn't smoke, and isn't using more than a quart of oil in about 1k miles.
I'd leave it alone. It's a machine, and they use oil. Replacing valve seals might help, but if the guides are worn it's a temporary fix.
If you're the anal kind and absolutely have to find the reason the bike used a quart of oil after a season of riding...
get out the checkbook. It won't be cheap.
Trying to keep the checkbook in my pocket ;D
I'd say your breather valve is pushing oil vapors into your intake valves.
I believe the breather feeds into the air box on that monster, so he'd also see oil pooling there or dripping out of the air box drain.
If the breather is pumping oil mist into the air box and then into the engine, you have an issue that needs to be fixed.
Could be rings, guides, valve stem seals.
If the breather is dry, and the valve stem seal doesn't appear to be torn or split, then it's probably the valve guide. You can use a dial indicator to check for play if you can't feel the looseness.
Almost any automotive cylinder head shop can replace the valve guides pretty inexpensively. If you can find an old VW mechanic he can easily handle it.
Get out your checkbook. The guys are spending your money. ;D
Quote from: ducpainter on April 08, 2015, 01:57:41 PM
I believe the breather feeds into the air box on that monster, so he'd also see oil pooling there or dripping out of the air box drain.
Thats a
very good point. I didn't think about that..
So that begs the question. Is there oil in the airbox??
Assuming the bike was running fine before, no blue smoke, no plug fouling, no loss of power and no excessive oil consumption you might be trying to fix something that ain't broke. If valve guide cleared and seals are OK and there is no excessive oil in the air box I say butt [n it up and see what you got.
Didn't notice anything unusual inside the airbox. I'll take a closer look at it tomorrow.
I'm leaning more towards finishing the valves/belts and buttoning it back up.
If I find flaky closing rockers that warrant removing the heads, I'll probably take a closer look at the guides/seals. The seals look fine thus far.
Shouldn't there be some oil on the valves and cams?
Quote from: scaudill on April 09, 2015, 03:22:37 AM
Shouldn't there be some oil on the valves and cams?
Yes, but he's concerned about oil below the guides in the intake port.
Oh!
Quote from: lazylightnin717 on April 08, 2015, 06:46:25 PM
If I find flaky closing rockers that warrant removing the heads, I'll probably take a closer look at the guides/seals. The seals look fine thus far.
Shouldn't have to take the heads off to replace a closing rocker. Pull the cam cover, cam, and then pull the push pin and the rocker comes out. Now getting the closer spring back on may be a PIA, but it's doesn't require head removal.
I'm well aware. Having to replace the vertical exhaust closers last time around was reason enough for me to say I'm yanking the heads if I have to do this again.
I'll cross that bridge when I get there.
Valves adjusted and only one flaky opener replaced. I visually inspected all of the valve seals and they looked fine.
I'm just going to button everything up and ride.
Good call IMO