AvramD

OK Everyone, I'm on my 4th throttle body boot. <B>However,</b> I don't think the 2nd or 3rd ones were actually torn. On inspection, they were visually in mint condition - not even dirty, much less any hints of any cracks.

I believe there must have been a flaw in my installation process that fixed the problem at first, and then deteriorated over time.

The symptoms I get are: a) lots of lag, about 1 sec when flooring it anywhere below 3500 rpms, b) fluctuating power delivery c) horrible fuel economy: 20 mpg cruising at highway spees, 18 when driving "like a normal person" around town, and 14-15 when driving hard.

Note: I do get what feels like 100% chipped power eventually, just takes longer to get there, and there are hesitations along the way.

I, like may others, could not get the sensor clamp back on, so I tie wrapped it. I am wondering if the tie wrap softend under heat, and stretched, alowing pressure to escape.

Changing the boot solved the problem the 1st & second times, but not the 3rd time. I put in the 2nd boot w/ my own tie wrap, and it was perfect for about 1000 miles. My dealer put in the third boot, and it was perfect for about 200 miles. The last one I changed 2 days ago, and the change did not help at all.

I noticed my dealer's tie-wrap on the sensor was not tight at all. I could easily turn the sensor in place, by hand. I don't know how it felt immediately after the job, only how it felt after the problem came back.

Now, I am noticing that the large hose clamp going to the actual throttle body has become very difficult to tighten. I'm wondering if the teeth inside it got chewed up, and the current problem is that it isn't tight, even though the screw is tight enough that I can't turn it by hand any more.

Can anybody shed any light or insight on my situation? What are others seeing for lag & fuel economy? Any correclation with tie wraps?

I'm sorry if this has been covered recently - I've been out of it, and I'm headed to my dealer in a couple of hours (after some meetings), so I don't have time to browse/search!

CBJ

Could you please tell me if a torn TBB could cause the engine to misfire or at least feel like it is misfiring and if it would cause the OBD system to switch on the malfunction light.
Thank You

George @ BostonAudi

That's better milage than I get...

Ron O

there is a lip , like a built in O ring in the TBB so leaking seems unlikely. Did you try the 15 second battery disconnect? -- That helped me in a similar situation. You might have to reprogram the radio after. Good luck

el rojo

My S4 is stock. 3,000 miles. I get minimal but noticable turbo lag, way less than one second. Your mileage sounds low...I see high 20s to low 30s, even, depending on the wind direction and speed, at 70mph cruise on FLAT pavement. A slight hill, not even noticable as a hill will drop mileage into low to mid 20s. The same "hill" in the other direction will yield 33 to 35 or My overall average mileage 50/50 hiway/city is typically around 23.

loanshark

The symptoms that you described don't really point towards a torn TBB. A few months after replacing my torn TBB, I started to feel low end power was nearly non-existant. RPM's would take forever to build, then full power would seem to come on after ~3000 rpm. I pretty much knew a torn TBB would not have been the source of the problem. Some info here on the board led me to believe the ignition was for some reason being retarded (bad gas, weather,...). I simply disconnected the negative terminal of the battery, waited about a minute, then reconnected to reset the ECU. And it worked! The beast was back! IF you haven't already, give it a shot and let me know what happens...good luck.

Rami in Houston

AudiBiTurbo

Remember- these are under pressure.
A Nylon tie wrap, by design, will not clamp with enough force. When replacing the boots, I reuse the large clamps (if you suspect a problem, get 2 new ones) and I use a small worm drive "hose clamp" to clamp the sensor. If you have troublem you can always grond down the clamp band, but I've not found it necessary. Oh, and do yourself a favor- use all stainless steel clamps.
Hope this helps.
Mark Rosenkrantz (European car tuner in NY)
AudiBiTurbo@aol.com<p>Mark Rosenkrantz
AudiBiTurbo@aol.com

AvramD

There are 2 or 3 split seconds when it feels like there is less power. I haven't had any error lights come up though.

AvramD

I hadn't thought of grinding down the small clamp for the sensor. I did reuse the large clamps for the 2 intakes, and the 1 output.