To answer your question, no shims needed. Audis have hydraulic lifters which do not require shimming. Get the valve job! There is gunk on the valve stem that you can't see!

Bob

 

When I did the head gaskets on my 1996 Audi A6 Quttro with 2.8L 12 valve AFC engine the right cylinder head alignment pins were broken. Since the pins were hollow, I tapped them for a #10 machine screw and pulled them out with an autobody slide hammer.
I also replaced the valve stem seals. You can get the valve spring compressor and a valve stem seal pliers from www.zdmak.com , www.samstagsales.com or www.baumtools.com .
The Bentleypublishers.com Audi shop manual CD is available at www.motorbookguy.com .

 

Damn, I wrote a long post and the system logged me out. I had no idea when submitting the post, so I lost everything I typed...

So, I'll be brief since I'm tired today.

Bob,
Please explain to me in more detail how exactly the hydraulic lifter compensate when the valves are grinded. That way, I would know exactly what to tell to the shop gentleman; and also understand myself.
By the way, tks for the "good news". (You just want to make me spend money, huh? )

hcw,
thanks for the tips. Concerning the Bentley CD manual...I do have it but, in some respects, is worthless. I said it before and I say it again...
I'll double check the alignment pins, although I pulled the heads straight up without any effort; I didn't jiggle them; I didn't have to bang on'em, or anything of that "brutal" nature that may have severed the pins.
I'll look tomorrow to see how mine look. Again, tks for the caution.

Jim,

I didn' have much time to work on the car (only a 3 hr-window after getting home before the dark sets), but it was a good day.
The intake manifold is cleaned... The exhaust is soaking in gas until tomorrow and it will receive the same treatment as its omologue.
To keep things brief, I would only say that 1 1/2 hrs soaking in gas is worthless. The OVEN CLEANER knocked the s&*t off in 30 minutes... I wasted 2 gallons of gas for nuttin'...
Anyway, here are some pics.
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tomorrow is another day...indeed

regards, guys.

 

Ya.. gas soaking is pretty much worthless. Good job otherwise.

As for the valve grinding, hydraulic followers, and shims :
Normally when you grind the valves and seats, your taking away material. This makes the valve sit 'higher' in the port and of course, this means the valve stem will also be taller in relation to the spring seat. This in turn means the keeper groove on the stem is higher and when the spring is reinstalled, it will have a higher compressed height and thus less force holding the valve closed. Too little force makes the valve close slower, and allows it to bounce or 'float' when doing so. Manufacturers specify a certain lbs/in of pressure at a certain spring 'installed' and 'compressed' height for this reason - to prevent valve float throughout the RPM range and to make sure the valve closes fast enough to get out of the way. This needs to be high enough to accomplish this but low enough not to collapse the lifter/follower. So, when you raise the valve stem installed height, you need to shim under the spring to bring it back into spec.

Now, what else happens is since the stem is sitting higher, it pushes more on the follower and increases what is called its 'preload'. This is also specified by the OEM. Too little and you get valve clatter like a sticky lifter. Too much and you can collapse the lifter which is bad and can cause it to shatter. Normally this is not a problem in a pushrod engine because you can also shim under the rocker arms to bring the assembly back into spec and relieve the pressure preload on the lifters. But, in an overhead cam engine the follower is directly on the valve stem and is squeezed between it and the cam. There are no rockers to shim or pushrods to change out for shorter ones, and you cannot raise the cam higher without major rework of the heads so what do you need to do? Mill some height off the valve stem if its only 1-3 thou you need, or install new seats and valves.

This is what I eluded to above (and what your tech was trying to say), and why I said if your seats are good, leave'm be. You can open up a real can of worms money wise.

Now, I did mention it first so I wont till you to not take them in. But, in my defense, I thought at the time that the head gaskets were bad. This would mandate that you take them in to get them milled and the valves done. But, since the gaskets and heads are good, with no real wear on the valves, I'd call it good and forgo the machine work. Up to you and how comfortable you are with that assessment, however. Remember, I'm not relying on the car . Personally, if I'm taking a motor apart I'm going all the way and do a complete rebuild

Now, if you have the cash to burn, you can go all the way and call Crower or Manley and order bigger, lighter valves and seats, get them installed and 3-angled, install new followers (have too with new valves), springs (need heaver due to bigger valves), retainers and keepers. This will allow you to increase the flow into the cylinders and increase power.. by about 10-15hp, maybe, on the top end. If you then want to actually make use of your new-found flow increase, you'll need a bigger throttle-body, free flowing intake, performance intake manifold, get the heads ported, better exhaust, and a performance ECU tune to take advantage of it all.

 

What happens when follower's collapse..... And when a dealer screws up.

http://www.audizine.com/forum/showthread.php?t=275327

 

wow, that thread is unbelievable.

 

+1...
I guess not all the Audi dealers have an apropriate shop (or qualified personnel for that matter) to back up the "luxurious" Audi reputation of "truth in engineering".


Jim,
there's no way I'm getting sucked up into spending more money than I have
(this has nothing to do with your suggestions/education pointers), if I really don't need to.

The few Benjamins I'm willing to spend on this thing will go toward the head bolts ($ 47 - ArizAutohaus) and tool ($ 21 - SJDiscountTools) first, and then toward whatever else I need or want to replace since the engine is apart:
- O2 sensors (both) - $ 167
- coolant temp sensor (2 pins) - $ 10 (FAE brand)
- coolant temp switch (3 pins) - this sucker is $ 41
- a new spark plug wire set - $ 81
- vacuum hoses... (depending on what I need)
- 2 wheel bearings kits - $ 88
- 2 injector repair kits (the terminals) - $ 16
- injector seals - $ 10
- oil pan gasket (lower) - $ 12.50
- new oil filler cap - $ 7 (although I can probably just replace the gasket)
- throttle body gasket (I had to scrape it) - $ 4 max
- other miscellaneous things (hoses, clamps, various o-rings).
- maybe a new oil temp sensor (if I can figure out which one I have in the car)

In the near future I need;
- 2 new front calipers
- 2 new hubs
- brake pads
- new rotors
- (I already have the CV axles)
- (I already have 4 new Continental tires)
- 4-wheel alignment

I guess I'll pass the valve job for right now.

Thanks for the wonderful and thorough explanation!
I'll keep updating the progress.

 

So all in all about $1000 for the head job, timing belt kit, WP, sensors, gaskets and seals? Not too bad.

 

Heh...
it may sound crazy or too "**** retentive", but I'll do a total cost and replaced parts list when I'll have the key turned back on.
Just for ***** and giggles...

 

Ok.. been a few days... ??