Low power output, B7 RS4

[kiwi_mtm]

Update:
> Confirmed the airbox flap was stuck. Now fixed.
> Currently have the inlet manifolds off and getting a good scub.
> Possible ECU S/W update being applied
> Drivers Lumber support valve getting fixed while its in there
> Replacing the lifting engine bay RS4 Sticker (that must be 5hp?)
Thank god for the factory warranty (incl maint)

Will get it back on the dyno when finished.

[kiwi_mtm]

UPDATE:

Got the car back after the airbox flap was fixed, and the carbon was scrapped off.
WOW, what a difference up top!
Have it booked in for a Dyno next week, and will share the results.

[RSKiwi]

UPDATE:

Got the car back after the airbox flap was fixed, and the carbon was scrapped off.
WOW, what a difference up top!
Have it booked in for a Dyno next week, and will share the results.

Very interested to see this (carbon off). Mine will be getting similar treatment from MRC before getting into its container to fly to the land of the long line of police cars

[madgreek]

Had my dealer take the manifold off and look what was found. Surprise!, I ton of carbon.... Car has 39k miles..Hopefully I'll be getting back 40 to 50 hp after they cleanup this crap.

[2manytoys]

Yuck! That doesn't look good at all. I'm sure you are going to notice the improvement when it's done.

What's the story behind this. Did you Dyno the car? How did the dealer come to the conclusion that they needed cleaning. Hopefully you get some after shots too.

[madgreek]

Yuck! That doesn't look good at all. I'm sure you are going to notice the improvement when it's done.

What's the story behind this. Did you Dyno the car? How did the dealer come to the conclusion that they needed cleaning. Hopefully you get some after shots too.

I actually requested to have the valves cleaned. I'm paying out of pocket for this. The car runs ok, but you can tell it was down on power (no kick at 5500). It has 39000 miles on it so I knew it was time for a cleaning. I really have no need to dyno as I'm sure I'll be getting at least 30 to 50 hp back.

I've written to Audi showing them these pictures and requesting reimbursement for this cleaning and extending my warranty as this is an obvious design flaw on their part.

[P_G]

madgreek, what sort of driving do you do and what type of fuel do you use? Just wonder if there is a correlation between the conditioms you use it under and some of the others that have had the same problem.

[madgreek]

madgreek, what sort of driving do you do and what type of fuel do you use? Just wonder if there is a correlation between the conditioms you use it under and some of the others that have had the same problem.

Vehicle Make/Model: 2007 Audi RS4
Location: New Haven, CT
Mileage: 31,200 @ purchase
Mileage@ W/Carbon: 38,850 @ cleaning
Oil used: Castrol Syntec / Motul 8100 Xcess 5w40
Oil Change Interval: approx. 4000 miles
Fuel: Shell V Power 93

Car is not driven in the winter, 60% rural roads 40% highway. My tach sees 7k to 8k rpm on a regular basis. Audi additive & BG 44k used roughly in 6 tank fulls. 4 oil changes

I'll start spraying Sea Foam directly into the intake prior to every oil change going forward.Hoping maybe this will keep the build up from getting out of hand.

[P_G]

Do you allow you car to warm up to full temperature rather then just after the 7k limiter temp before using the full rev range? The cars with highest carbon content appear to be those that are left to stand for a while and they way they are run. Since yours is left over winter I wonder if that has an impact. I am fortunate with mine in that it sill make near as dammit rated power but then it is run everyday.

[2manytoys]

When Audi stripped my engine they found worn valve stem seals. My brothers A4 2.0T had bad carbon too and the heads were removed. They also had worn valve stem seals (he commented yesterday that he is no longer using oil).

I'm wondering if a larger percentage of the deposits, or those with bad buildup is because of worn seals. Is Audi able to check this without removing the heads? It would be worth checking if it can be done.

[madgreek]

Do you allow you car to warm up to full temperature rather then just after the 7k limiter temp before using the full rev range? The cars with highest carbon content appear to be those that are left to stand for a while and they way they are run. Since yours is left over winter I wonder if that has an impact. I am fortunate with mine in that it sill make near as dammit rated power but then it is run everyday.

I generally wait until the oil is at at least 190 before I step on it.

I'm wondering if a larger percentage of the deposits, or those with bad buildup is because of worn seals. Is Audi able to check this without removing the heads? It would be worth checking if it can be done.

Thanks for mentioning this. I sent an email to the dealer asking if they can inspect the seals.

[pad125]

When Audi stripped my engine they found worn valve stem seals. My brothers A4 2.0T had bad carbon too and the heads were removed. They also had worn valve stem seals (he commented yesterday that he is no longer using oil).

I'm wondering if a larger percentage of the deposits, or those with bad buildup is because of worn seals. Is Audi able to check this without removing the heads? It would be worth checking if it can be done.

That's interesting, you may know I had mine cleaned last year which involved engine out etc. Problem I have now is the car use to do 7k miles on a litre of oil and now it only does 2.5k. The dealer says there's nothing wrong as its within tolerance but nobody seams able to pin down the additonal usage. Are you saying that checking valve stem oil seals is an 'easy' job?

[Terry1948]

I sometimes wonder if the people with a lot of carbon dont know about mine as it has never been inspected move their cars short distances i.e. stop and unload their shopping have a cup of tea 2 or 3 hours later move their car into the garage. I know if I have done this the car smokes like an old Battle ship on the next start up.

[2manytoys]

When Audi stripped my engine they found worn valve stem seals. My brothers A4 2.0T had bad carbon too and the heads were removed. They also had worn valve stem seals (he commented yesterday that he is no longer using oil).

I'm wondering if a larger percentage of the deposits, or those with bad buildup is because of worn seals. Is Audi able to check this without removing the heads? It would be worth checking if it can be done.

That's interesting, you may know I had mine cleaned last year which involved engine out etc. Problem I have now is the car use to do 7k miles on a litre of oil and now it only does 2.5k. The dealer says there's nothing wrong as its within tolerance but nobody seams able to pin down the additonal usage. Are you saying that checking valve stem oil seals is an 'easy' job?

I don't know if you can check them without taking the heads off, but there may be a way, I'm not sure?

When I was going through the whole Carbon Build-up drama, only 5000kms after a clean my valves looked pretty bad again. Oddly Audi didn't suspect valve stem seals at all (even when stripping the engine). It wasn't until I looked at the old heads, before they went onto the new short motor, that things went in another direction. The heads didn't look good so I asked Audi to send them away to be checked before they put the engine together. The report wasn't good (valve stem seals worn) so a new set of heads were ordered. In the end I think I was lucky to have a dealership that asked as many questions as I did.

[pad125]

Is that more a case of the value guilds then? Not looked at the detail of the heads/guides/valves etc but once-upon-time changing value guides was a possibility. I’m guessing this wasn’t an option so you got new heads?