Jim Castronova

Sam, to avoid confusion... the term engine mount bracket/oil cooler ....um......please help me understand what you are referencing here. My understanding is the oil cooler sits bolted onto the block by itself, so if there's an associated bracket assembly that goes with the oil cooler, I just learned something I didn't know. The interesting thing is the oil cooler has 4 holes, one in each corner and a 5th on the metal cooling tube coming out of it, so referencing a bracket and a top middle bolt has me a bit confused. What is this thing you're referring to?

Jim Castronova

nevermind...you're referring to the alternator mounting bracket...I get it
thnx

Sam Zubel

So i did some thinking on this and my apologies. I am wrong in what i was saying and confusing 2 different things. So the engine mount bracket since its been so long i was confusing it thinking the engine mount was one of the things that needed to come out. What i really meant was the support bracket in front of the oil cooler/ and different modules what the oil cooler is bolted to. The Oil Filter Housing!. Opps sorry. So on the D3 A8 the oil cooler is bolted to the Oil Filter Housing, then that is bolted to the motor. In your write up the Oil cooler is bolted directly to the motor. I've probably caused more confusion then needed.

In doing and Making sure i wasn't loosing it ha, I found these on a quick search and if you go through them all will make sense, even my pointers i started with. Props to the person/s that made these 2 write-ups, good stuff and they are definitely on point with everything. They don't forget to mention how important and how many 8 mm allens are needed haha and the importance of tapping the sockets in before loosening.

1. audipages A8 Oil Cooler Removal and Reinstall

2. https://www.audiworld.com/forums/a8-.../#post15572661

-Cheers

Jim Castronova

no worries Sam....its all good. the fact is, there is the alternator bracket that needs to come off to reveal the oil cooler and I had plum forgot about it....soooo.....we'll just consider that as the engine mount(5 bolts) and as it went with the job on the oil filter housing o-ring replacement, I have assembled this crazy collection of 1/4" Torx and Hex bits and various sized sockets, ratchets, 1/4 in palm ratchet and 2 dual handled bit wrenches....for those tight spots. there is no bolt that will escape. That said, there is nothing like rigging a hex key to a 1/4 in mini socket 'cause in the end, whatever works was the right tool. You have been very helpful and it shows just how easy it is to be thrown off by the minor changes these different engine variants all seem to be be vexxed with. I am going to try and do this without dropping the front subframe at first....if I get hung up I'll drop it. I saw the diagram for the earlier 4.2 which depicts the oil cooler adjacent to the filter housing and as the saying goes, if it ain't broke...don't fix it, but no, they decided it should be moved, sooo... same with the G28 Crankshaft sensor....they moved it too, from a readily accessible spot to a you have to be kidding, hidey-spot down behind the coolant return tank. hence the assortment of duplicate bits and creative attachments. Used to be a 15 minute job....took 3 hours and a lot of bad language and scraped skin.

I'm going to do this repair on Fri....thinking while I have it apart I'll throw on a new belt(its 10years old) and replace two of the coolant hoses which are showing pressure bulges..one on the alt the other on the cooler. I'll be keeping in mind the need to be dead-on with the initial turns on those bolts you mentioned. Hopefully these o-rings last a while 'cause I have zero interest in ever having to do this again. I feel sorry for people who can't turn a wrench and aren't rich 'cause Audi maintenance costs per hour put this repair at just under $900 with tax and all because of 2, $6 rubber o-rings............ but, this car, this a6 4.2...it is the best handling, most responsive and smoothest car I've ever owned so sometimes y'a just shutup and fix it. Meanwhile I'm tooling around in my '94 SL600 coupe so it coiuld be worse.. I'll def keep you posted on how it goes/went..thanks again

Jim Castronova

A6 4.2 Vier
I like your methodology much better.........at least we're working on the same engine variant..
Thanks for the pics 'cause they make the difference for where you're trying to connect the dots...some of the comments though well-meant, are not useful when the engine they're referencing has the components clear on the other end of the engine. lol. Fact is...you left it simple and clear just what I need to do.
Thank-you

Sam Zubel

Thanks for the kind words, Im just trying to do the right thing here, if you know something useful, if you can help out then help out kinda thing.

One more thing on this bracket dilemma were in. Now that you've said what car you'll be doing this on, let me say one more thing.

Depending on engine code, Model car and year It can be different things, Oil filter housing, Alternator bracket to be clear.

As far as your car having or not having that small coolant pipe union, I would purchase it just to be safe. Example ecs is great with their " fill this fit my car" selector at the bottom of the page you're viewing but in this case i know first had certain A8's have them, but when selecting A8 it says does not fit, or when searching under A8 that part does not appear any where when looked for.

This is copy and paste from a listing selling the metal replacement pipe.

D2 Chasis A8/S8 cars from 1997-2003 with the 4.2L Engine
C5 Chasis A6/S6/RS6 cars from 2000-2004 with the 4.2L Engine
D3 Chasis A8 cars from 2004-2007 with the 4.2L Engine
VW Phaeton cars with the 4.2L Engine

A6 4.2 Vier

Plan on replacing the (4) variable timing solenoid o-rings (2 on top of the engine 2 and 2 near the valve covers) next. Mine started leaking at around 140K miles. It is nice to have a non leaking audi for a change.

Jim Castronova

Funny you should mention it.......I have changed the pax side valve cover twice and still feel seepage at the lower rear area...at Audi parts today to pick up a replacement hose and brought up the topic of these o-rings(thank-you) Bought 4.... and a new (3 now) valve cover gasket. I'm resolved to someday look under my car and not see any evidence of oil...anywhere. That, and not have the smell of burnt synthetic oil hitting my exhaust manifold in heavy traffic where I'm sitting idling for a long red light. Sure appreciate the insights and information...

A6 4.2 Vier

Hopefully the new O-rings will fix your oil leaks, the old ones will most likely come out in pieces. Due to the location of the variable timing solenoids near the valve cover gaskets, they tend to drip oil on the rear lower portion of the valve cover as you noticed. Looks either like a valve cover gasket leak or rear timing cover leak.

I kind of miss the smell of hot oil vapor and the white smoke coming up from under the hood. Most of all I miss the puddles of oil on my driveway and garage floor.

Jim Castronova

Seeing how we have similar issues with our cars...here's something you might have some background with,,,worth a shot. Ever since I brought this A6 in for the catalyst recall, I've been running around with my MIL light on due to a G28 (Engine Speed Sensor) Incorrect correlation fault. It also has a G28/G300 Cam Sensor fault Incorrect correlation as well. I've replaced the G300 (pax side) and recently got a new G28 Crankshaft Sensor installed and it still comes back after I clear it. Neither fault seems to have any performance impact but I was thinking how nice it would be if I could just get it to correct itself....just a nuisance thing but I'd like to be done with these issues.. You have any thoughts on this?? Sure like to hear them.