Timing belt job -- what have I gotten myself into??

[kday]

I don't think the aux radiators would help much in stop and go traffic. Since there are no fans the car needs to be moving at a decent clip for them to have any effect. I could see them being very useful for high speed highway driving in the southwest though.

Regarding removing the intercoolers, yes, the auxiliary radiators are riveted to the intercoolers. You need to remove them as a unit, so you need to drain the coolant, etc. There are also brackets which hold the leading edge of the front fenders that go through the ductwork, and I'm not sure you can wiggle the assembly off without removing those. Once everything is disconnected, they go out the top. I'll post pics of my epoxied ICs later tonight, which should make it obvious how they attach to the car.

[4everRS]

Great posts kday. Thanks for sharing this with the forum.

Regarding the aux radiators, on a track, I assume these rads would provide a substantial amount of extra cooling. Also, assuming your not driving in reverse, and air is moving at 50 mph+ front to rear, would there really be a heat soak problem?

[905084]

Awesome pics kday!. Although I'm scared to do my sons A6 4.2 timing belt now. 4.2Crew, the I/C's come out with the aux rads and the rear cooling shrouds all in one piece. Just take the fender to unibody brace off that sits in between the rear shroud plastic(3x30 torx). I busted my first rear plastics to bits before I found that.

[kday]

Glad everyone is enjoying the pictures. There is a practical benefit too -- sometimes I don't remember how things were originally put together! I'm still searching for the perfect system for keeping track of which screw goes where though. ETKA can usually help in a pinch but sometimes it's vague.

The timing belt procedure itself is actually really easy. The Bentley instructions are clear and straightforward assuming you have all of the special tools and don't have to improvise (I suggest not improvising.) The hard part is getting everything out of the way, and then (presumably -- I'll find out soon enough) putting it all back together.

[Aronis]

kday, nice write up...i'm tempted to give it a try....

Mike

[kday]

Ok, finally getting close to wrapping this job up. I thought I'd get it done over a long weekend but all of those "while you're in there" tasks really add up. As long as the epoxy is dry on my intercoolers tomorrow I should have it back on the road on Monday.

The JB Weld thinned with Acetone flows nicely and is easy to apply, but it takes a lot longer than usual to dry.



Both of my intercoolers had one area where most of the leaking was -- the bottom inboard corner. I removed the fins around there with a thin screwdriver to make sure the epoxy had good coverage. I used the paintbrush dipped in acetone to clean everything as well as I could. The oil stains were telltale signs of where the leaks were.




Next up -- Auxiliary radiator bypass. One of mine was leaking, and I debated whether I should replace it, or reconfigure the system to use one radiator, or just remove the system. I opted to remove both. I used some of the hoses to make a bypass:



I couldn't tell from the cooling system diagram whether it was OK to simply cap off the aux circuit. If it's in parallel with the main radiator, then capping off would be better, since this would effectively short circuit part of the coolant flow. But the presence of the one way check valve makes me think that it's not so simple. Does anyone know what the coolant routing is on the Euro cars that didn't come with the aux radiators?

I needed a hose union for this bypass using the leftover hoses to work. The hose ID is ~16mm and presumably something could be found at the auto parts store but for some stupid reason they aren't open after midnight! Fortunately I have a little lathe and some aluminum stock:




Finally, one note on the timing mark on the harmonic balancer:



That line was perfectly centered when I started. The keyway on the balancer is larger than the key on the timing sprocket, and it can be off a little. This is harmless except it will make it a little harder to get the crank lock pin in the next time.

[hahnmgh63]

Take a look at this thread as it has been covered. ETKA has a whole subsection on the Aux radiators as they are just an add-on option that can be removed and pretty much capped off. Some of the pipes can't be removed easily with the engine in the car but I removed mine while the engine was out and if you look at the diagram of the Aux radiators in the post below, I removed about every single hose, pipe, and clamp in the ETKA picture.
http://www.rs6.com/showthread.php/22...with-01E/page4

[kday]

I missed that in my searching, thanks. Where does #36 source from? That's what I couldn't figure out.

[hahnmgh63]

#36 is the hose that is behind the engine cowl that hooks to the Cooland Resevoir. Steve Ken's thread had the Balkamp hose/pipe rubber plug pics and I just used the part #'s from the pics and ordered an assortment of them from Napa autoparts online.

[kday]

Ok. I'll revisit this when I have the engine out for the 6 speed swap. Anyone know if the cars without the hot weather package have different metal pipes (lower rad pipe & coolant tank pipe) without these additional ports?

[hahnmgh63]

I don't have my computer with ETKA on it with me here but if you have ETKA you can go to the ROW (Rest of the World) pages and look at the cooling system and compare the pipes. That is how I determined that the Aux radiators were just a tagged on addtion to the cooling system and that capping off the feeds without bypassing them was all that was needed.

[kday]

I decided to build a coolant pressure tester to make sure I got everything back together right.



That's some 1/8 NPT pipe epoxied into a spare coolant cap. This is a little tricky since the part of the cap you grab and turn is not the part that seals.



I use this leakdown tester for a lot more than leakdown testing. It's handy because with the two gauges and built-in restriction you can see leaks by the difference in the gauges.

I am glad I did this test, because I found two (!) leaks. One was this:



This is the radiator petcock. I guess the O-ring seized in place and got torn when I unscrewed it to drain the coolant. Fortunately I found a matching O-ring in a kit on the shelf.

The other leak was the lower radiator hose. It was leaking at the clamp to the pipe. The clamp was in the right place, and looked OK, but it wasn't holding. It was a very slow leak at 1 bar but quite fast at 1.5 bar. I replaced it with a worm gear clamp. Something to watch out for...

[SzymekCRX]

Good job, kday. Had the same simple idea of the tester

[SFJ_RS6]

Hello kday. Nice job here and thanks for the pictures! I've been following this thread with interest since you're dealing with many of the same issues that I am.

I have my engine on my workbench and am planning to replace seals as a preventative measure. I haven't invested in the Audi special tools for seal removal and installation. I got my main seal out the same way you did, a method I've used in the past. Cam seals - it sounds like you used your Audi tool for cam seal removal. Based on your experience, do you think the cam seals could be removed using the sheet metal screw and pull technique? Just interested in your thought on this. I could invest $$$ in the Audi tools, but if I can do it as well without them....

Thanks,
Steve

[kday]

Sure, there isn't anything special about the cam seals that precludes the screw method. I did it that way on an Audi V6 (same seals, or at least very similar) and it worked OK. It just always made me nervous and I was looking for a better way. I'm happy to lend you the tool if you want it, though as I mentioned it didn't quite live up to my expectations. I would say it's not any easier or any faster, it's just less error prone.

[SFJ_RS6]

Thanks for letting me know what you think about this, and for the offer to loan me the tool. When I get to the point of replacing the cam seals I'll scope it out, and let you know if I want to borrow the seal remover or not. Given the high prices for the bits on the RS6, there is something to be said for going the less error prone route.

BTW - my daily driver is a '92 100CS with the 2.8L 12-valve V6 engine that we bought new. Sounds like you have some experience in that vein. I like the car and engine, and it's doing fine going on 200,000 miles. Good to have when my RS6 is on the bench!

Steve

[kday]

Yes, I am familiar with the 12 valve for sure. My wife drives a 96 A6 Avant that is on the cusp of 250k. I've been thinking about replacing it with something newer but it just keeps going. Well, I did replace the engine a few years ago, but it's been great aside from that.

[SFJ_RS6]

Yep - basically the same car - and you have an impressive number of miles! Just curious - what prompted your engine replacement? Our '92 has had it's share of problems over the years. It was my start at learning to do mechanical work on Audis. The biggest thing now is that it's becoming hard to get some parts for it. I blame a lot of its problems on being the first year of a new design. I sometimes jokingly refer to it as a mechanic's car - only a mechanic can drive it to compensate for it's idiosyncrasies!