How about GC in a '96 A4 2.8 V6?

[Tom300M]

My girlfriend has a '96 Audi A4 with the 2.8 V6. This car had been her parents and from what I've learned this car has had dino changes since 96 (Weight unknown, it currently has a window sticker reminder from a Shell Service station, so it probably has 5w30 or 10w30 in it). It currently only has about 48,000 miles on it. I've looked under the oil cap and and was not happy with what I saw. I couldn't exactly see much, but on the inside part of the cap, there was little bit of a black chunky sludge like substance.
I'll be changing the oil this weekend. I tried searching, but couldn't find much info on this 2.8 engine. Would GC be a good choice? I know on the Mobil oil site, it recommends 0W-40, but the Autozone near me has plenty of new GC with the European Formula note on the front of the bottle and no Mobil 1 0W-40. Thanks!

 

[Auto-Union]

I'm going to say no, not yet, I've used GC in my MILs 1995 A6 12v, it worked good, but I never used it again. That engine is clean too. You would need to have a clean engine for GC to work well. The problem is that engine needs disassembling and "de-carbing" of the intake and PCV/valve cover, the insides cleaned by hand. I'm not kidding. Your particular car has lo miles, unless rarely driven, usually means short, sludgy, trips. I bet you have a CEL on too. Vacuum hoses need a full replacment on most because they collapse inside w/o you knowing. Want more? A cleaning of the MAF is cost/efective. A ECU reset afterwards is the ticket. Disconnect that battery and let it sit overnight or touch the DISCONNECTED battery cables to together to reset the ECU. Back to the oil service...if you do not want to do a home "decarb", I would start with a kero flush (1q) in the current oil, cold engine for 10 min at idle. Run a cheap 10w-40 for a short time or a 15w40 if it burns oil and do an Auto-Rx treatment, save the GC money and buy ARX. I would not be looking at synthetic for that engine until next winter. Until then, just use conventional 10w-40 for winter and if desired a High Mileage oil after you start to clean it a bit. I use GTX HM for winter in 5w30 (thick, 12cSt) and the 10w-40 GTX HM in summer. I don't know of those oils are worth $3/q but they are good. When you want to try synthetic, WalMart synthetic is a thick 30, Rotella T Synthetic 5w-40 is another good oil for that engine, so is MaxLife Synthetic. SO, conventional oil for a few short changes, kero/ARx, conventional High Mileage oil, even WalMart HM or MaxLife, then maybe synthetic, but this engine does not need synthetic at all, it needs more conventional changes to clean it a bit. I have some filter part numbers right here.

Puralator L30257
STP S3569
Mann W940/25
BOSCH Premium #3500

 

[Auto-Union]

Here is a pic of the inside of a 12v after 122k of 10k intervals of Syntec 5w-50. You can only hope you engine is like this. It had Syntec rom new. Worth the money and effort!

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=1;t=005119

More likely, your engine looks like this:

 

[moribundman]

Oh, what a pretty 12v!

Tom300M, when you looked in the oil filler hole, you were looking at a splash shield that obscured the view onto the engine uppers. Even if you saw some deposits on the shield, it doesn't mean your engine looks necessarily like the one in the bottom picture. You'll have to remove the valve covers to get a good view Make sure to clean out the integrated valve cover mesh filters. They tend to get gunked up which negatively affects the PCV system.

When installing new valve cover gaskets, make sure to use dabs of RTV in the proper spots without accidentally clogging easily overlooked oil passages near the fore and aft camshaft bearing caps.

 

[Tom300M]

Oh, I'm certain it was taken on many short trips. I believe her father used it to go to work maybe a mile away each day, comming home in the middle of the day for lunch and and then going back. More recently, like this past winter and spring, it was used at least a couple days a week or more for what has to be a 1/4 mile or less trip to school, with occasional longer trips, but very little highway. (Unfortunately, the area school is in and the times of day she was traveling basically necessitated that she take the car on those short trips)

quote:

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More likely, your engine looks like this:

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Its funny (well, not really I guess) that you linked to that picture and post; a month or so ago I found it and showed it to my girlfriend and told her the bottom one was probably what her engine looks like.
Well I'm not sure what I'll do now. This car still really is her father's and I just said I'd change the oil. I don't know if I'd really feel comfortable removing the valve cover gasket on it, or even asking him if I can do that or any of the other mentioned treatments as in implying they took poor care of the car. Ugh, well I'll have to see what my girlfrind thinks I should say/ask.

 

[Auto-Union]

It's normal for them to get gunked up. It's a common dealer service to "de-carb". Short trips are killers, you could explain the "oil not getting heated fully" thing to him....not his fault. You could talk to him about it and show him those pics. Dealer wants a lot of money for a decarb, so I dunno. I'd go to town with Kero, ARX and conventional oil with a big stack of filters. Chevron Delo or Mobil Delvac 1300S 15w40 will clean and offer decent change intervals. For flushing, nothing more than SUPERTECH 10w-40 is needed. I use Havoline sometimes because it blends with Delo. GTX is another good conventional 10w-40.

 

[moribundman]

If the valve cover gaskets are not leaking, don't bother. If they leak you have the perfect excuse for wanting to take the covers off.

You will need to:

- remove the upper engine cover
- pull the spark plug wires off the spark plugs
- remove the valve cover breather hoses from the valve covers (pinch the clip and pull without breaking it)
- remove the valve cover bolts (I think they're 5 or 7 mm Allen heads)
- remove the valve covers; if they are stuck, tap them carefully with rubber mallet or pry them off with a plastic of wood putty knife
- wipe the mating surfaces on the cylinder head clean
- be careful to not spill your coffee or beer onto the cam
- clean the valve covers, especially the integrated mesh filters with a plastic-safe cleaner (brake cleaner)

To install:

- apply dabs of RTV in the corners near the fore and aft cam bearing caps, but do not block the nearby oil passages
- torque the valve cover bolts evenly and criss-cross to 84 in-lbs (10 Nm) -- do not overtighten!

You will need these parts:

- two new valve cover gaskets (ca $15 each): 078-103-483-J
- Permatex Ultra Copper RTV Silicone or similar
- a rag (with which to wipe)
- acetone (for degreasing)
- torque wrench or calibrated wrist
- proper Allen socket (7 mm?), extension and ratchet

Required time: ca 45 minutes for both sides.