s4master1

Don't feel so bad, this is the S4 4.2 set up.

Mister Bally

At least it is the same simple fiberglas clip that holds it in like my '01 New Beetle as well as 4.2L A8 setup.

mishar

Well, from your point of view... May be you should send some flowers to the guy who put that sensor there.

s4master1

my point of view has nothing to do with this, as I stated before (quattro is a disadvantage in big sedans or any car with big engine).
there's a logic reason for the sensor to be where it is.
Agree on the engineering factor that simply sucks, however has not been that long that a lot of people wrote and argue here how great this car is compared to any other sedans, well since the very early 80s Mercedes has used double firewall in large sedans (actually the first who introduce double firewall), but the forward part of it was removable allowing access to anything needed done in the back of the engine. that to me was superior engineering.
As I stated many times when it comes to the whole package nothing beats an S class, specially when it comes to cost of ownership.

mishar

I heard you before and I heard you now. I just believe I never heard explanation for that Quattro statement.

Sure there is logical reason for that sensor placement, but there were more logical spots. Starting with known sensors liability and accessibility logic. Placing it there only says that they don't care.

I never had big Mercedes but I think you are right. It seams they do care.

s4master1

to make it easy just check this out.
stand on the side of your A8 right at the center of the front wheel (left or right) with the hood open and look toward the engine and tell me in relation to the center of the wheel where the engine sits.
now if you can look at any Benz or Bmw and see the difference.
sadly on a quattro the engine must sit in front of the wheels because of the front differential and torque converter/clutch assembly.
this causes a huge weight problem causing stability and handling concerns as the center of gravity rest way in front of the middle of the car(on a few weather related situations quattro is an advantage).
however the topic here is coolant sensor location.
because Audi/Vw has to make engines as short as possible (vr6/w8/w12) it also has to make cooling systems accordingly, because of the circuit flow of coolant and heat generation the sensor location has been assigned at the rear of the right cylinder head as been the best most optimum position.
the problem I see on this particular sensor is the quality of the part as it fails a lot, we all know there are better quality sensors lasting so much longer than this some even the life of the car.
other sensors like O2, exhaust temp, is just ridiculous to tell technicians/customers that the engine needs to be removed to replace them, but it gets even worst, the 2.7 engine mounts have the same suggested operation.

mishar

You are right. This is temperature sensor tread and better sensor would make way less problems. I do not plan to redesign Audi engines, not for free for sure, but I would bet my car that there is simple way to make it accessible. Actually, your experience with this cars is valuable. You didn't say is it possible to change that sensor without removing engine.

Although this is sensor tread I can help You mean Audi's 4WD is not really well designed. I would agree with you about that. This one is just a bit different and way better. You may recognize it.

s4master1

they all have their unique good and bad issues, this systems are not new at all, I seen Benz cars with the front differential inside the engine,s oil pan which is made out of cast iron.
but in large sedans they all make things complicated one way or another.
my argument is simple base on experience.
we are in a very competitive world nowadays, and manufacturers no longer take the time to properly research and design products(even Mercedes).
look at these 2 samples.
RS6 and 500e
the first time I needed to replace a steering rack in the RS6 I found out by audi that the engine had to come out, some techs may actually consider sending flowers to the enginner who designed this.
I actually curse his/their names as when you look at the car closely they just took an A6 body, flare the fenders and stick a bigger engine on it without regard about maintenance or repairs in the future, the flaws are obvious everywhere in and out the car for example who uses a timing belt system on a twin turbo v8 and suggest to replace it every 35k and then change the interval to 15k miles?, that,s just dome on any car, just use a chain/gear system,
then when you open the trunk you can see the battery is seating almost in the middle, yes in the middle of the trunk, if you need to carry 2 sets of clubs, good luck the battery is in the way. and even with quattro I can easily make the rear end of an A6 4.2 break loose due to weight distribution.
I can go on and on on all models but we have to be fair also as other manufacturers are not any better considering the options they have to offer.

mishar

My experience with powerful front wheel drive cars and powerful rear wheel drive cars makes me happy that I am driving 4WD. I would be happier if it is not so nose heavy and that's why I like those pictures I attached.

I wonder why RS6's timing belt is under more stress then mine. It is running similar camshafts at similar speeds.

Kpj

Just wanted to update you guys on the issue. I went ahead & let the dealer fix the sensor (G62). Audi of Rochester was able to cut the price down to $1600 for the entire job, so that made it a bit easier to swallow (not by much though).

I went ahead & ordered the Bentley repair manual/guide, but there was no way I would be able to remove the engine myself. At some point, I will also get the VCDS (VAG-COM) dongle for diagnosis for future issues. I do have a faulty 'soft door closer' on the driver's door & the trunk no longer powers open with the button release. I think one of the pistons/lifts is dead. These seem to be 'easy' fixes that a DIYer can tackle, so in time, I hope to accomplish these tasks.

Anyways, I just want to thank you guys again for all of your help. It was great to hear all of your info/opinions on the situation. I do love this car & hope to keep it in my possession for some time.