Reto Sommer

I posted some notes a while back and got some good response. I checked the common things like the TBB if it was torn or if the turbos made drastically more noise -> they seem to be ok.

Have spoken to my Dealer, but have not gotten anywhere with them. They are booked till the 20th of July (Silicon Valley) and got told they couldn't do anything till then.

This is what I can tell from my experience. The boost seems delayed or not kicking in at all sometimes, like if the waste gate was stuck. It happens mostly in gears 3rd and up and at RPM over 2500. I had a 1998 A4 2.8 Avant before and know how it accalerates and my A6 does just the same sometimes (since it is the same engine in basics, that would make sense).

I would take a small turbo lag in consideration but what I see is a lag that hold up over a range of about 1000 RPM or through the whole band.

The diagnostics doesn't find anything wrong. I went into the diagnostig mode from the AC but wasn't able to find any value that represents the boost pressure.

To my questions:
Does anywone know if the diagnostic mode from the AC on an A6 2.7T shows something like the boost pressure?

Or has anyone seen this boost problem on their car?

The last thing of course may be that this is just my imagination and thatfore I would like you to ask if someone in the Bay Area is willing to drive my A6 (someone with a 2.7T A6 themselfes)and compare to theirs if mine has a problem?

Thanks,
Reto.

eduardo

... I'm in Mountain View during the day. I can drive yours, you can drive mine.

Reto Sommer

I work in Santa Clara, but I have Tuesday and Wed. off. I would come up there if you have the time. Otherwise we can maybe do it on Thursday or Friday? Let me know, I am flexible most of the times (thanks to a very good job and boss :-))

Try my email, since I will check that more frequently than this forum.

anosis@jps.net

Thanks,
Reto

Sacto Ming 2.7T

I am very interested in the results of the test drives. The original post reads like something that I also could have written with my 1 month old 2.7T (6sp), except I have had it into the dealer twice. The first time at the dealer, they could see there was a power problem in test drives and from the diagnostics (didn't get the details). After 2 1/2 days they uncoverd a cam sensor was shorting out and causing the power problem. The behavior was the boost was missing 75-85% of the time just 3 days after getting the car as well as the check engine fault light came on. After the 4 day stay in the shop to diagnose and fix I got the car back & drove it home. On the trip home, I noticed a "whooshing" noise & the loss of power. By the time I got home (35 minute drive) the check engine light came on again. (talk about frustration) I called the shop again and they suggested checking the vacuum line near the Throttle Body Hose & sure enough the hose had come off -- whew! -- or so I thought. I put the hose back on tightened the clamp & things seemed Good. After a day or 2 the check engine light went out and things seemed good. Then, after a few more days I started to notice the power problem again. Not as persistent, but probably 25% of the time. Especially when "flooring" the accelerator. If I eased into the accelerator, I would usually get a slight lag and then go. I checked the hose it seemed ok. But I didn't pay for "2.8 like" power so while out on business for 3 days, I took it to the shop again. They could see the power problems on the diagnostics and indicated that the hose had slipped and replaced the clamp and I got it back. In general it has been better, but I now have the same problem of is it my imagination or do I not have power on demand like I expect. Clearly, when I floor it my imagination is most active. When I punch it, it doesn't lag and snap to like I would expect it just sort of accelerates like my old VR6 passat nice but not bi-turbo'd. Again if I ease into accelerating it seems to work better and much more consistent. Right now my imagination is that I have boost about 75% of the time and I miss it the rest. Oh, one other thing, if I'm already at higher RPM's (>3500) and punch it, then it seems like I do not get any boost more often then when I'm at lower RPM's.

This very problem is in fact why I came to the forum, looking for similar problems. I also found the "S-CARS.ORG" write up on the S4's losing power (see http://www.s-cars.org/home.html article) and it seems to hit it on the head, so when I get home I'll re-check the hose as well as the Throttle Body Intake Hose for any sign of leak or split. It seems obvious from the article and my experience that somewhere I'm getting a sporadic vacuum loss.

So, Reto, does this match your experience (minus the cam sensor)?

BTW, I'm in the Sacramento area and have no wait to get into the dealer. Don't know if you'd want to take the time but compared to waiting until the middle of July it at least could be an option.

Thanks,

Dave Young