RS6 power loss

[buzz]

Hi All,

I had My RS6 Now for 6 months and driven it 5600Km's, Recently I am experiencing power loss when oil temp rises above 65, I was even more dissapointed when My cayenne turbo ( driven by my son) ( May be I am getting old !) sprinted faster to 100 with two car lengths, any way the problem was reported to the dealer and they replaced the control unit + two air mass sensors. nothing happened, the problem is still there. I live in a country where temperatures vary between 40-47c.

Does any one know why is this hapenning? and is this normal.
please help

Best regards,

Buzz

[Aronis]

It's clearly the quality of your Gasoline.

Where do you import your oil from?

Mike


LOL


Just kidding....

Limp mode occurs at higher oil temps. I have never seen it myself, but I live in a cool climate. I would be careful of having them just "try Changing" this and that....

Good luck.

Mike

[Hy Octane]

This sounds very much like what has been happening to mine for the last 15 months..
Can you describe a little more in detail what happens and what your gauges say? Do you get a Check engine light? Does it go away or stay limp? I have been trying to get this problem fixed and Audi have changed everything but the motor. still no idea what is causing it, but you might be the first other person to report suffering from this.

[buzz]

Hey guys,

Thanks for replying, no engine light, no messages, only hesitation to accelerate and as if the Turbos stop spinning and the engine feels out of breath. The best time to drive it is in the morning when the engine is still cool and the temperature is normal.

Buzz

[gregoryindiana]

What options are there?

In Saudi Arabia, getting the extra oil coolers of the RS6+ should be no problem for you.

You can get alcohol spray that would spray a mist in front of the intercoolers, cooling the charge air; won't cool the oil much.

You could contact MTM regarding their additional air cooling louvers that expel additional air from the engine compartment. You wouldn't have to worry as much as most of us about rain pouring into the engine compartment.

I don't know what else you can do; that is a really hot ambient temp, and a turbo engine's worst enemy is heat. It sounds to me that your ECU is doing its job to protect your engine from running outside its design parameters. If you do mods to override the protections, I hope the people that do it will stand behind their work.

[buzz]

Hi Gregory,

Probably the extra oil coolers are the best option, though I was offered by the dealer to get an updgrade from ABT, they will upgrade the ECU to 505Hp's!!

I am really dissapointed, I have a Cayenne turbo and it performs flawlessly, My brother has a 996 turbo S with no issues at all. I have contacted the dealer and they promised to solve the issue by next week. I'll update you as soon as I get the car back. I appreciate your feedback and keep'em coming.

Many Thanks

Buzz

[Hy Octane]

Obviously, they must think this is not proper or they wouldnt have changed the ECU and the MAF's.. its exactly what they did on mine first.. then they changed the exhaust gas temp sensors and then the thermostat.. It still cuts power after driving for awhile..
This sounds like the sam,e thing I have going on buzz. Please keep us posted on what they do to fix it as AoA has sent me their best and my RS6 has laughed at them.. Its going back in Monday because the last monkey that worked on it put it back together wrong and now theres a problem with acceleration and a nice high pitched whining sound coming from the front right as well as a knocking sound coming from that little black valve on the right side of the engine thats connected with 2 hoses above the right wheel well..
You guys whose cars have had no problems should feel very special that you dont have to deal with this shit..

[SpinEcho]

Just a few ideas...

1. Don't assume the Audi dealer knows what they are doing. Just because they are changing pieces of equipment doesn't mean much. Similarly, their offer of an Abt chip won't do much good if your engine is going into limp mode (assuming the Abt chip has such a feature - which you certainly want if the engine is in fact too hot!)

2. The RS6 is known to have inadequate engine cooling. I think in your case this applies more to air temperature under the engine bay, and I'm not sure extra oil coolers would help much. Short of holes in the hood (in properly designed locations), not much might help, short of an Arabian ice age...

Sorry to sound so pessimistic, and I hope I'm proven wrong!

[JAXRS6]

I've had subpar performance issues in two circumstances:

1. After symptoms from bad gasoline lingered for 2000 miles, my ECU was replaced. The car still had periods of subpar performance, so it was replaced again. When symptoms persisted, dealer tech called Audi engineer in Germany and, after a long talk, my wiring harness was replaced. Problem never returned!

This was 18 months and 30K miles ago, so I don't remember all the details, but it felt like turbos were not engaging. I don't recall even noticing the oil temp, and the subpar performance was not related to ambient temperature. Sometimes it just felt like it was running with 300 hp instead of 450; other times it was fine. The wiring harness was causing the ECU(s) to short out, or words to that effect if I recall correctly. Sometimes my ECU light would go on; a couple of times my traction control engaged during without prompting. But all that, too, disappeared after the wiring harness was replaced. (PS - Wiring harness replacement is very labor-intensive, so neither dealers nor Audi are eager to pursue it as a first solution IMO.)

2. The hotter the weather, the more performance suffers. I was just noticing tonight that with temps down into the 50s F for the first time in months, the car is really eager to take off ... compared to recent days, with highs in the 90s, when it seemed significantly slower...er, less fast.

I don't know why the Porsche turbos would hold up better in hot weather. From everyting I've read, all turbos perform better in cold air because it is more dense. Maybe the P cars somehow depend less on the turbos for their torque?:confused:

[RS4Ever]

hey guys, dont mean to interfere in this discussion ...
i dont own an RS6 however i do remember that once on this forum someone had a similar problem and what was proposed was to seal a vent [at the bottom of the engine bay?? - cant entirely remember] so that the engine wont suck in hot air around the engine?? - was that it?

again, i could be wrong


good luck

[Rupert]

Originally posted by RS4Ever
hey guys, dont mean to interfere in this discussion ...
i dont own an RS6 however i do remember that once on this forum someone had a similar problem ...

Here's the thread - worth a try I suppose!
http://www.rs6.com/forum/showthread.php?threadid=5536

[clam]

How about the MTM hood exhausts (http://www.mtm-online.de/en/performanceparts_equipment.html) .

http://www.mtm-france.com/mtm_allemagne/mtm_rs6_clubsport.jpg

The mtm hood exhaust for the Audi RS6 was developed particularly for hot countries, in order to make it possible to stream out the hot air. This is to get down the engine temperature.

The RS6 has a lot of hardware in a very small space. That's probably why it suffers more from the heat than the Cayenne.
I remember a guy on Audiworld telling he could feel the heat coming out of the scoops.

[trex]

Originally posted by buzz
Hi All,

I had My RS6 Now for 6 months and driven it 5600Km's, Recently I am experiencing power loss when oil temp rises above 65, I was even more dissapointed when My cayenne turbo ( driven by my son) ( May be I am getting old !) sprinted faster to 100 with two car lengths, any way the problem was reported to the dealer and they replaced the control unit + two air mass sensors. nothing happened, the problem is still there. I live in a country where temperatures vary between 40-47c.

Does any one know why is this hapenning? and is this normal.
please help

Best regards,

Buzz
power loss is common in hot weather specially when its extremely hot (Saudi Arabia) ,i do feel that loss in power but not as much b.t.w i have the ABT ECU upgrade and did try to do what you've done with a Cayenne turbo and it was the other way around of cores after i did some hard driv'n to raise the oil temp ......
i hope you get your beast back asap with all problems solved

[buzz]

Hi All,

Many thanks for all your kind suggestions, some I will try, especially the airduct solution, I just came up from the garage and felt alot of air coming from the engine bay at the drivers side (left hand drive) no air though on the right side and this air is hitting the the occordion like rubber seal which houses one of the air mass sensors!

I will be at the dealer first thing tomorrow morning and see what solutions they have for me. Again many thanks to all and keep em coming.

Trex: we should meet some time especially if you are in the Riyadh area. drop me a line.

Buzz

[SpinEcho]

Originally posted by JAXRS6
I don't know why the Porsche turbos would hold up better in hot weather. From everyting I've read, all turbos perform better in cold air because it is more dense.

Because they get better cooling than the RS6.

[minimad]

Even though it's not as hot as your contury, we have also 36 degree C summer here in Taiwan. I also experienced power loss in hot weather. Since I intalled MTM oil cooler & ATF cooler, things are getting way better. the oil cooler works so well that reducing oil temp at least 30 degree C. The ATF cooler also works fine. I used to have check engine light up after hard driving, now it's gone. I have MTM stage III mod (535 bhp), which generates higher engine temp than OEM ones, so I think it's obvious helpful.

[JAXRS6]

SpinEcho -- thanks, your explanation certainly makes sense!:D

minimad -- what's an "ATF cooler"?:confused:

[Hy Octane]

The problem here is not one of ambient temperature causing a programmed cut in boost to avoid detonation, what is happening is that the engine is cutting boost when the oil temp goes above 65 degrees Celsius.. thats only 150 degrees F on the US gauges and cooler than the normal water temp.. If you look you will see that this is within normal operating temps. Audi sees this is wrong and is swapping out parts to try and find the cause. This is the same thing I have been going thru with no cure as of yet. I am hopeful now that someone else is having the same symptoms they will be able to find and fix this soon.

[buzz]

Hi Hyoctane,

I have sent the car to the dealer today and we went on a full test drive and the technician experienced the whole thing from start to finish. I will keep you posted with all the details and things they do untill we both get the cars back to original shape. I will try everything possible. If nothing happens then the car will be sold and this will be the last Audi I will buy. The most enjoyable Audi I had was an S8. I guess Audi should stick to normally aspirated engines.

Buzz

[Hy Octane]

Hey Buzz..
I have thought about getting my money back for this car but every time I do, I come up with the fact that Audi will only take it, fix it eventually, and resell it to someone who will then get to enjoy it the way I was supposed to. I'm not prepared to do that just yet .. I'll stay with it a little longer as I hope we are running out of things to replace and soon will find the culprit..

Is your car a 904xxx or a 905xxx Vin #?
Was just curious if ours were made close to each others date and there might be a coincidence there.. Mine has an 11/03 build date.. maybe a bad batch of a certain component..

I'll be axniously awaiting your results..

[buzz]

Originally posted by Hy Octane
Hey Buzz..
I have thought about getting my money back for this car but every time I do, I come up with the fact that Audi will only take it, fix it eventually, and resell it to someone who will then get to enjoy it the way I was supposed to. I'm not prepared to do that just yet .. I'll stay with it a little longer as I hope we are running out of things to replace and soon will find the culprit..

Is your car a 904xxx or a 905xxx Vin #?
Was just curious if ours were made close to each others date and there might be a coincidence there.. Mine has an 11/03 build date.. maybe a bad batch of a certain component..

I'll be axniously awaiting your results..

Let me check tomorow and find out. I'll keep you posted.

Buzz

[SpinEcho]

Originally posted by Hy Octane
The problem here is not one of ambient temperature causing a programmed cut in boost to avoid detonation, what is happening is that the engine is cutting boost when the oil temp goes above 65 degrees Celsius.. thats only 150 degrees F on the US gauges and cooler than the normal water temp.. If you look you will see that this is within normal operating temps. Audi sees this is wrong and is swapping out parts to try and find the cause. This is the same thing I have been going thru with no cure as of yet. I am hopeful now that someone else is having the same symptoms they will be able to find and fix this soon.

Wow - that's really ridiculous! So it IS a problem with oil cooling?!? Can anyone confirm this? 65 degrees Celsius seems like a temperature the car would reach if my grandmother was driving - if that's the case everyone's car is regularly having its boost cut - is this really possible?

[JAXRS6]

Originally posted by SpinEcho
Wow - that's really ridiculous! So it IS a problem with oil cooling?!? Can anyone confirm this? 65 degrees Celsius seems like a temperature the car would reach if my grandmother was driving - if that's the case everyone's car is regularly having its boost cut - is this really possible?

I don't think any of this is safe for a solid conclusion, since Hy's car is not yet fixed -- so the solution remains at large in his case. Plus there can be other causes for power loss, such as mine which was explained on the previous page. My power loss was not related to any temperature and was resolved only after replacement of my wiring harness under warranty about 30K miles ago.

[buzz]

I agree the problem remains at large and I cannot tell you exactly what is wrong untill they put their finger on the cause. Meanwhile all what I said earlier about power loss happened when the temperature of the oil rose higher.
Buzz