Ok.
I'm in the process of taking the Intake manifold and the heads apart, and after removing the valve covers I noticed what I believe to be a problem.

The crankshaft is at TDC, and the camshafts are at TDC, as seen in the previous pics. After pulling out the sprockets, the camshafts didn't move, and I'm sure of that.
However, as said, after removing the valve covers I noticed that 2 of the passenger side bank valves are "shut", as comparative with all the other 10 valves (4 more on the same bank, at 6 more on the driver side bank).

Please, guys, let me know what do you think.


-


TKS.

 

When you do 'Top Dead Center' its ment 'TDC of #1 Cylinder'.

It looks like in the pictures that the valves you claim are 'shut' are acyually 'open'. When the lifter/follower is on the base circle of cam is when the valve is actually closed. The cam lobes then push on the lifter/follower which in turn pushes the valve.

Thats the way it will be, 2 cylinders will be closed: one on compression stroke, the other on power stroke. The rest will be somewhere in between.

no worries


http://auto.howstuffworks.com/camshaft.htm

 

Thanks, Jim.
I should have already known those are the valve "lifters". In my haste and rush to find what I'm dealing with, I just used the "valves" wording.

Well, I appreciate the reassuring and the link. Afterall the engine was running "normally" - not considering the "diesel-like" sound.
However, what I have trouble digesting is why those open valves-lifters are in different clusters?

Shouldn't a cluster of 2 lifters/valves represent one piston?

If that's the case then the following is happening:

A) - Depending on which is the intake/exhaust valve, those two "open" valves are in the same "slot" of different clusters. Notwhistanding whichever they represent (either as intake or exhaust position), it looks to me that 2 pistons actually have the same sequence, in that passenger side bank.

B) - If that's not the case, and just one piston has the valves open right now, how come that the two "open" ones are in the same slot of different clusters?

Man, I really have hard time understanding this in a logical way.

 

I'm not real sure what you are asking.. But I will try.

The actual progression of valves is not repetitive, ie: I/E, I/E, I/E. To make routing of gases easier in and out of the engine, and in an effort to keep the intake air cooler and exhuast hotter, the ports are paired, ie: I/E, E/I, I/E. This pairs two 'hot' ports and two 'cool' ones.

Here's a good example:

http://www.7ent.com/images2/sevr0017.JPG

The shiney valves are the exhausts. As you can see they are paired. You will find heads where this is not true (3/4/5 valve, Hemi, etc), but it IS true for a majority of 2 valve, wedge type heads.

So, what you are seeing, and this is my fault earlier - was eating Easter Ham , is in the top pic, all the valves are 'closed' or very close to it and are either just opening, or have just closed. In the second pic, the cylinder to the left is closed, and the other two have either an Intake open, or an Exhaust. I couldnt tell you which one is which at the moment, but it is One Intake on one cylinder and One Exhaust on the other.

In a six cylinder motor, you fire a cylinder every 120 degrees of crank rotation, so you will have 3 cylinders doing the I/E valve tango on one revolution, and the other 3 the next revolution. Once you get every thing back together, leave the covers off and handcrank the motor while watching the valves, you'll see what I mean.


Hope that made sense? I'm really full and lethargic right now

 

I hope you enjoyed your Easter ham!
My meal consisted of pork and tomatoee potatoes seasoned and dressed with garlic, both cooked in the oven. Don't know how many people still enjoy garlic nowadays, but I love it.
It was a saying: An apple a day keeps the doctor away.
I like to paraphrase that into something like: Eating garlic keeps the doctor away, but also everyone else . Every now and then I crave some and usually is over the weekend when I'm home and don't go anywhere that particular day...

Back to the issue at hand.
I'll try to make better sense of what I was asking.

You were saying that the TDC is actually the TDC of the # 1 cylinder.
So my latest question addressed the fact that on that passenger side bank, actually two cylinders have "moved", or "open" valves, not just one.
I knew that typically two valves per cylinder means that the intake and exhaust valves are paired, as you pointed out.

What I wanted to know was why two cylinders appear to have "open" valves (as it shows in the second pic for both clusters - let's call them front cluster and middle cluster; or cylinders 1 and 2) instead of just one cylinder, since TDC meant the TDC of # 1 cylinder?
Anyway, I guess I was concerned for no reason for a moment, there.

None of the extremly knowledgeable guys deemed necessary to chime in, so I would stake my hat on it that there's some underhand betting on:
"50 to 1 that he won't be able to put it back together"
" We'll just sit tight and laugh when he'll advertise selling the car for parts b/c he can't get it back together"

Thank again, Jim.

 

I'm still kinda lost. Are you saying that what is suppose to be #1 cylinder is not at TDC (one valve is open)?

In the pics above I'm assuming the front of the motor is to the right in the driver's side one (top). Is the front is also to the right in the passenger side pic (bottom)? If so, #1 is not at TDC. However, I dont know if this is a problem because after looking around, there seems to be a consciences that #3 is actually at TDC with the marks lined up and cam tools in, which would be the cylinder to the left in the bottom pic. Germans

Dunno.. here's a link that actually shows the confusion: http://forums.audiworld.com/showthread.php?p=18706968

Maybe thats why no one else has replied



The ham was great! Thanks.. Also had Kielbasa and Sauerkraut (tradition at my in-laws house) and... Garlic Potatoes - cut, not mashed. MMM, mmm.

Still up sucking down the Tums

 

Darn, as soon as I opened that link and glanced over the first cylinder order I ran outside and took pics of my coils pack...as I was sure it doesn't match the order in my car.
Coming back in, I noticed that the gentleman covers more scenarios, but I'll have to read thoroughly and try to understand what he talks about.

Nevertheless, it was a propice time to put my "s%7*&" together in terms of pics.
I am sure it would be clearer now. The first cylinder cluster on the passenger side coincides with Cyl # 1.

Moving toward the rear of the engine, the cylinders follow the order : Cyl# 2 (middle cluster), and Cyl # 3 (at the rear).



-
-

On the driver side bank, the order from the front of the block toward rear is as follows: Cyl # 6 (front)

followed by Cyl# 4 (middle cluster)

, and lastly Cyl # 5 (rear cluster)
.


So, based on what I observe now, Cyl # 1 has indeed one valve open.
Also, Cyl # 2 has a valve open...
So, what I wanted to know is why 2 cylinders have open valves at TDC, instead of only Cyl #1?
(sorry for bolding it, but this is the main point I would like to make sense out of)
Does it make more sense now what I'm trying to find out?
Tks.




P.S....By the way, excellent Audiworld thread find! Tks (should have myself tried to search on the topic before bemusing ppl with my stupid inquiry)...

 

Well, after reading through that thread, now I'm really getting confused...
Moreover, that thread used to contain useful visual aids (pics) that no longer are part of the posts. It makes it more difficult to understand some of the explanations without the initial accompanying illustration.

Before going any further with my comments, I would really like to get a sound understanding of this "TDC" notion that was almost on my tongue but I never articulated it right>

Ok... so the cylinder comes "UP" to its apex (TDC), toward the top of the engine.
Shouldn't be that both (intake and exhaust) valves/lifters of that cylinder are AWAY from the cylinder?
If that's the case, then the following is true:
- one is already closed, and
- the other one either pulling away (CLOSING...or still OPEN; same thing) -as the cylinder advances UP, or being already in a pulled away (CLOSED) position as the other one when the cylinder reaches its apex?

If this second valve/lifter is on its way up (still OPEN), then that means the cylinder didn't reach TDC;
hence not my # 1 cylinder, but my # 3 cylinder is actually at TDC.
(as my # 1 and # 2 cylinders have 1 open valve, each)

Is that a fair assessment, or I'm swimming in murky waters here?

 

Welcome to the funny world of cars

Ok, I'm off my ham and tums high so maybe I can give this another shot...

First, I started this off on the same premise as the person whom you quoted, ie: 'TDC is when #1 is at the top of its travel on the compression stroke and both valves are closed'. That really is the definition of TDC as it applies to motors and timing. However, it seems that in this case, 'TDC' is ment as 'TDC of cylinder #3', and the 'TDC' marks on the crank is really ment by Audi to be a 'Timing Mark', ie: a mark used to align the crank and cams. This just happens to coincide (prolly on purpose) with #3 being at TDC. After looking around a bit, it seems that most manuals do not even refer to this mark as 'TDC' but rather as the 'timing mark' with the Bently translation saying 'until engine at TDC with timing marks aligned'. It gets the point across, but prolly isn't accurate as the 'engine' is not at TDC, which would imply that #1 cylinder would be at TDC, but it clearly is not as born out by several people posting that #3 is always at TDC with the cam tools on.

So, to answer your question (finally ), #1 is not at TDC but are somewhere in between and so the valves are actuated. Looking at the firing order, at this point in time, with #3 at TDC, #1 has open exhuast, and #2 has an open intake.

So, sorry for the confusion.. it was partly my fault for ***-u-me'ing 'TDC' in this case ment #1 cylinder. And is what i was refering to with You've got it...


Sorry I posted it... However, I wanted to show you that even peeps who have been at this awhile can still be confused.

 

Well, Jim
I don't know how to really thank you for all this time you devoted to answering all my questions, even if they were silly or lacking advanced knowledge of how exactly the things work inside the engine. I praise you for such a great patience and, as said before, willingness to help.
Before this Audi, I only performed minute maintenance on our cars, without getting too involved with "mechanics" in general due to daily grind constraints.

I know that whomever put together the DIY mentioned in that thread cautions ppl that changing the head gaskets is not a job for your average beginner. However, I am pretty stubborn (can you tell?) when it comes to reassembling right something I start pulling apart... especially an Audi with Autolite rusted spark plugs inside...
(Who the Fck puts Autolite spark plugs in an Audi, anyway?). The top of the cyl # 5 spark plug came out with the wire...
That makes me even more determined to make this car run better than I bought it.

Anyway, I guess I can continue with my "demolition" with an eased mind.

TKS again from the bottom of my heart for all your trouble!
cheers.