Boost is Back......But

[jeffw]

Having diagnosed that I was down on boost ('cos I kept getting overtaken by TTs at the last trackday [img]images/graemlins/tongue.gif[/img]) I've just replaced the TBB and the 2 DVs. The TBB had an almight tear near the main jubilee clip [img]images/graemlins/frown.gif[/img]

The difference in the car is amazing....like a new car !

But......while I was changing the DVs I noticed that the passenger DV and hoses had a film of oil in them. The drivers side is clean so I assume that one of the turbo oil seals is on it's way out [img]images/graemlins/frown.gif[/img]


Ho hum.......

[DJG]

Glad you've got the performance back [img]images/graemlins/smile.gif[/img], but sorry to hear about the turbo [img]images/graemlins/frown.gif[/img]

AMD are checking my car over tomorrow looking for air leaks and TBB tears etc. Not that I particularly think anything is wrong, but want to make sure all is well while I still have a warranty.

Also want an opinion on my turbos which do whistle a bit.

Not sure what the expected lifespan of the S4's turbos is. Maybe I need to take a trip to Executive Audi ( [img]images/graemlins/thumbs.gif[/img] biturbo).

David

[wazza]

[img]images/graemlins/bigwave.gif[/img]

[DavidT]

Jeff,

My car had some oil in one of the pipes when I looked at the valves the other day. I dunno if it is a sign of problems or not. They are not noisy and the car uses little oil. It could be years of build-up?

I will ask my dealer (they are pretty good to deal with) and report back.


David

[toasty]

Mine were a bit oily too mate.

I just put it down to the crankcase air recirculation thingy that our engines have.

[keyser]

nothing to worry about [img]images/graemlins/smile.gif[/img]

oil in those pipes, it's normal

[jeffw]

Thank God for that ......I almost had to upgrade to K04s [img]images/graemlins/smile.gif[/img]

[DJG]

Had an interesting visit to AMD today.

Wanted to get the TBB and other hoses checked for leaks and have a power run on the rolling road.

Turned out that one of my DVs had a torn diaphragm AND had become disconnected. [img]images/graemlins/confused.gif[/img] (Brittle hose??)

Suppose I could have got this fixed under warranty, but understandably AMD didn't want to do the power run without the problem being fixed.

Now have much cleaner throttle response! Car feels much, much better. Guess I have been living with the problem for a while.

Car also feels quicker, BUT when I timed my 6th gear 50-70 several times I got 6.6s instead of the usual 6.0 to 6.2s. [img]images/graemlins/mad.gif[/img] I hope this is due to the fact it is 27 degrees today.

Rolling road results were 271BHP @ 5900RPM and 329 lbft @ 2600RPM, so everything was OK.

Also had my front end clunk diagnosed as a worn front left lower arm and one of the top arms, so a trip to the dealer beckons.

[img]images/graemlins/thumbs.gif[/img] AMD.

David

[Dippy]

Car also feels quicker, BUT when I timed my 6th gear 50-70 several times I got 6.6s instead of the usual 6.0 to 6.2s.

David,

I checked my 6th gear 50-70 times recently as well. Consistently around 3.5 - 4 seconds. [img]images/graemlins/grin.gif[/img]

You need the Miltek system and a chip!

Go on... you know you want to... [img]images/graemlins/FIREdevil.gif[/img]

[Golich]

Jeff,

I can confirm ecatly the same oil residue on my passenger side pipe into the TBB. My car needs about 1/2 litre oil in 10K miles. I've often wondered if it's worth removeing the the intercoolers to see how much oil is in them. One lad told me it's not unknown for intercoolers to require cleaning out after some time. I beleive some of the Fiate Coupe guys vent the crankcase breather set up into a seperate trap tank away from the intercooler. [img]images/graemlins/yellows4.gif[/img]

[DJG]

Thanks Dippy, not! [img]images/graemlins/<beep>_you.gif[/img]

[jeffw]

Cheers guys.....I was starting to worry !

[Dippy]

Thanks Dippy, not! [img]images/graemlins/<beep>_you.gif[/img]

OK, serious reply then.

Having had my air intake system car apart to install the APR bipipe, I can agree with the others that SOME oily residue should be expected. There was very little in mine as I did the mod around 15,000 miles so my engine was still tight (as it is a bit even now).

However I'd have thought that if the oil can actually drip from the pipe, or one is significantly worse than the other, then something must be wrong.

There again what do I know? [img]images/graemlins/spineyes.gif[/img]

[DJG]

Don't worry Dave,

I'm only jealous [img]images/graemlins/thumbs.gif[/img]

Your mods are actually great value as they give your S4 the same performance in 6th as my standard one in 4th (maybe even 3rd when you get 3.5s [img]images/graemlins/frown.gif[/img]).

If I had the spare cash would be interesting to try adding your mods in reverse i.e. full Miltek and cats first, then chip and look at the in-gear acceleration in each case

But I am hi-jacking the thread again.

Still a bit [img]images/graemlins/frown.gif[/img] that my car seems to have got slower with the new DVs even though the power and torque were fine. Hopefully the heat......

[img]images/graemlins/beerchug.gif[/img]

David

[Dippy]

Actually the heat shouldn't affect your car. The biturbo engine is easily capable of reaching its standard level of performance even when the ambient air is very hot. Why? Because the ECU works on the principle of meeting demanded torque and boost. So in theory its max torque should be the same no matter what the ambient temperature.

I could believe that modded S4s and the RS4 may be affected by ambient temperature, but not the standard S4.

My guess is that your loss of about 0.5s is due to the new DVs taking that long to close. Your torn DV "may" have closed quicker since it was leaking and therefore there was less resistance against the air flow???

Maybe my sparring partner (Toasty) could comment?