hi there, new here, i’ve been on audiworld for 10 plus years but i’ve heard this forum is a little more in tune with the S6 5.2…anyway, i have an 08 S6 with about 115k miles and am going to replace the coilpacks - my mechanic said to go with the Bosch ones, but just wondering if there is much difference between the brands or if anyone recommends any? was looking at the Denso ones on rockauto and the price is very appealing at about $185 for 10…thanks
Welcome to the forum.
For me, I use the OEM Bosch ones. Myself and others do this because the OEM coil packs have the part revision in the part number itself. With OEM you know if you’re getting the latest updated version of the part.
I know some people have used the Denso units with no units. If it’s close money wise. My recommendation would go with the OEM
Yup thats why I use the bosch CPs I think T verion has been out now for the longest time with good long term performance.
coil packs are something you should only have to change every 50k so the extra money might be worth it as the bosch units seem to be fine for 50k where you see people replaceing the denso units at 20k… For all I know the denso units could go longer but from what I have gathered densos dont seem to last as long
that’s good to know, i have had good luck with denso plugs in the past with my old A6 but no other parts - and actually the bosch ones at ECS are only a couple bucks more each so i’ll go with them as originally suggested - thanks for your help…aside from plugs which have already been done, is there anything else you think i should be addressing while doing the coils?
check the oil seperator and all of the hoses for cracks.
Without knowing the other mods or miles its hard to say what else might be a priorty.
From what we have found so far there is a rock solid formula for maintenance
Check for carbon top of the list. If the carbon goes unchecked you can take out an injector as a matter of fact most injector testing shows that injectors after 80k are down by almost 20% some more.
Check your intake manifold to make sure the flaps are not broken and when you have the intake off put in the JHM intake spacers. BIG BIG help in bringing down intake temps. Helps keep knock down and a cooler air charge. Some have said it helps keep carbon at bay for even longer. I really like the lower intake temps myself the car wont heat soak until you turn the car off.
Obviously check the fuel filter as that can get clogged and that also have the pressure regulator in it so its good to keep in good shape. If you dont have oil dripping down from the valve cover gaskets leave them alone.
If you want to pull more power out of the car the JHM ECU tune is miles better than anything else ever made ever. The JHM tune really wakes the car up. Several people have posted about it. I think we have a thread from a guy who switched from APR to JHM and still thought the gain was night and day and the performance results show JHM makes a big big acceleration difference with a nice help in MPG
That so far has been the hot list
thanks for the recommendations, i will look into them when i have the coils changed
Check back and let us know.
I think I got the denso coilpacks from ECS when I replaced them all; I had a couple failing and it was a budget thing knowing I’d replace them all with the latest OE ones this winter along with a set of flowmatched injectors (now that I’ve collected 25 or so of them!)…
regardless of what the vehicle history or previous owner(s) state; You need a carbon clean. Now. And again every <indeterminate amount of time/miles>. Without, you’ll kill the injectors, plugs, coils, all the things induction. Clean it.
Replace the oil separator. It’s easy to get to, cheap to replace and from all the threads I’ve read and my own experience a failing separator put excessive oil and crap in general all up in yer intake’s guts most likely the leading cause of intake flap failure/breakage. They’re cheap and easy to replace. Buy three; under $50, it’s the cheapest of the most important parts you’ll replace - https://www.amazon.com/gp/product/B01N7T37HJ/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1 The hoses to/from the separator are covered in a braided sheath masking the true condition of the lines themselves. Not saying you should just blindly replace them, but pretty sure at 60,000miles+ they’re not daisy fresh on any car especially with the underhood heat that comes standard.
Phenolic spacers; JHM’s the only game in town, baby. While not necessary (strictly speaking), they delay underhood heatsoak considerably. You’ll still get a blazing hot engine bay, but you’re intake will stay just a bit cooler until it plane saturates the whole engine bay. They’re not cheap, but they don’t break the bank either and they come highly recommended.
vacuum lines - another very easy item to replace that’s extremely necessary to keep at zero leaks. If any of the hoses are old, brittle, cracked, leaking it will cause your short term fuel trims to wander all over the place… Running too lean, too rich or both depending on what your cracked vac lines decide to tell your ECU will lead to excessive buildup and burn off in your cats and eventually damage the O2’s and the cats - this is bad. Replacing either means dropping the engine. Just replace the hoses. It’s cheap insurance.
Injectors; DO THIS; https://jhmotorsports.com/shop/catalog/product_info.php?products_id=4082{9}213
no one - I repeat NOONE in North America really can do this at any cost. I’ve got about 25 injectors now total (including the 10 in the car) from various sources and I can confirm beyond a shadow of a doubt these things are fickle. These things are not consistent. $1200for a flowmatched set IS A STEAL (they’re what, $130/ea?) - $600 for a core exchange is a no-brainer. They will be superior in every way to both buying new and just buying whatever you can find. At any price. After a thorough carbon clean, this is by far the most important item in making a happy 5.2 If I had spent the $1200 a year ago, I would’ve spend 1/3rd the money I have trying to kill misfires… Don’t be me. Just do this. All C6S6’s could use this.
Intake; chances are you don’t have the revised part. The original failed so much, they revised it years after it was out of production if that tell you anything. $1800 is a lot to part with, and we don’t have any longevity data (IE, no reports yet of the revised part failing) but the odds are against you’re original intake NOT failing. Don’t replace it if you don’t have to but read up on where the failures happen, how to diagnose and put it on your to-do list because odds are it’s on it’s way. If you have any oil, any dirty debris at all pooled in your intake, the PCV/separator has failed at some point and I guarantee your flaps are on the way…
oil leaks; just because your S6 isn’t leaving puddles on the driveway doesn’t mean it doesn’t have a leak; there’s 3 main areas that all S6 V10’s leak from; if you pull the intake for any reason address these problem areas whether you’re leaking or not. it’s a negligible add for your mechanic and maybe an extra hour of your own time if you’re the one turning the wrench.
Trans; flush the fluid every 80k miles. 60k miles? The unicorn tears that Audi puts in a bottle isn’t cheap - rather it’s ridiculously expensive for what it is. It’s listed as a “lifetime” part. It is not. Change it if you’re over 80k miles for sure IMO. also needed are the filter and gasket.
Once you’ve done this I promise you’ll have 100% ready checks and zero misfires. When you hit this milestone, now you need;
JHM Tune and catback - these two things alone will make you love your S6 more than almost every other vehicle. By far the most cost effective grins-per-mile upgrade.
Then, ditch the heavy stock wheels for …anything else really. Rotational mass makes a HUGE difference on this car. For the ultimate in weight savings at the corners but the JHM LW rotors…realistically you could save as much as 25-30 lbs PER CORNER with both. That’s just silly.
Then at 80k+ miles, it’s time to refresh all the bushings - complete control arm kits can be had for as little as $400.
Do all this and you’ve got a car that’s sincerely better than delivered from the factory… Do none of it and you’ll be using that AAA quite often.
Great post compugeek5150 very well put. I have noticed even on the V10 motor even with the motor and engine bay at its hottest with the JHM spacers your still about 40deg F lower temps than without. That is the smallest I have seen often its even lower temps
thanks for the write up compugeek, those are all great suggestions…i’ve been on vacation so i haven’t had a chance to address anything yet…this is starting to remind me of replacing the turbos in my old 2.7! can anyone recommend someone to do carbon cleaning in CT? i’m assuming my normal shop has never done one so i’d prefer someone who does it regurlarly
Ah… I see you too are a glutton for punishment! Just like you I went from the 2.7 to the 5.2. I ditched the 2.7 before it blew a turbo because I was paranoid that one day it would happen and I’d wind up having to pull the motor and drop several grand in to new K04 turbos.
…Instead I dropped a couple of grand into an intake and injectors.
Glad to see you’re being proactive with this stuff given your car’s mileage.
couple grand, haha, that’s funny! i think i dropped about $12k in all on the new turbos, but that did include K04’s, downpipes, exhaust and a host of other improvements/maintenance…in hind sight i probably should have dumped the car but i was too attached…i had a few good years with the upgrades and then everything just went south, alternator, water pump failed, steering rack leak, etc…so yes, my biggest fear is having to drop the engine in this car, so it looks like i’ll be dropping $1.5-2k in parts alone plus labor as insurance
you guys got out while the getting was good. The 2.7 is ok but the v10 performance is comming along and once you get the bugs worked out the 4.2 and the 5.2 are powerhouse motors.
The big issue is that the first few owers generally dont do the big maintenance works so you end up doing it as a new owner. once the maintenance is done you dont have to mess with it for a while.
If you miss the b5 power… After you get the maintenace work done get the JHM tune. It transforms the car with the JHM tune and a few other supporting mods your in RS4 acceleration numbers