2003 RS6 engine issues...

[Marcin]

That's a pretty encouraging result. Yeah, loose spark plugs would definitely cause issues. Did you order the correct NGK plugs? It's important on this car.

The engine load % isn't useful. It can (and often does) go above 100% on a stock map. I don't know what the ECU strategy is for the load so let's ignore it for now.

Your low requested boost is curious, if you have no DTC. The stock max boost is about 1750-1800 mbar (there is no min, ECU often specifies zero boost).

Now that you've fixed the issues, clear all the codes in all modules, drive the car for a few miles. Stop the engine, turn off ignition. Drive another few miles. Do this a couple of times. See if any DTC appear. Check TCU and ABS for codes in addition to ECU.

Then log a short run with partial and WO throttle. We need to log the following:

Group 002: Engine Speed Engine Load Mass Air Flow Mass Air Flow
Group 032: Adaptation (Idle), Adaptation (Partial)
Group 115: Engine Speed, Engine Load, Boost Pressure, Boost Pressure

Then another run logging the following:

Group 001: Engine Speed, Coolant, Lambda Control
Group 112: Engine Torque spec, Engine Torque actual, Torque Reduction
Group 063: Accelerator Pedal Position, Kick-Down

I'd also want to see what the EGT are reading. Can't remember where that is.

You don't have to log the groups, you can choose the individual readings.

That'll do for now. Let's see what that reveals then we can dig further.

Thanks! Yes, it looks like there is hope, she just needs some TLC.

I will complete these tests hopefully this evening and report the results. The engine had NGK PFR7Q sparks in, can you please verify if these are the correct ones?

[Shoppinit]

Yup, those are the ones.

[Marcin]

Yup, those are the ones.

Hi Shoppinit,

Please find the logs attached. The only one I couldn't find was the Engine torque spec as group 112 is all EGT. I pulled some torque from gearbox group 009. But can easily repeat the test if needed.

About DTC, after I started the engine and let it run for a moment (was connecting my OBD) it almost cut off for a split second, the check engine flashed and disappeared. I found the P1455 Exhaust Gas Temp sensor 1 fault (implausible signal) and also found the 01119 (Gear recognition signal) fault in the brakes, TCU was clear. All faults cleared and did not return after a couple of starts and stops/ignition off. After all the heavy runs I checked for faults and found the Exhaust Gas temp Sensor 1 Upper limit exceeded P1453.

If some of the runs are not long enough I can repeat them, it's difficult, especially the WO ones.

I hope this data will help to understand what is going on...

[Shoppinit]

There's nothing that jumps out wildly. Couple of things: Your MAF readings are a bit low. You should be getting close to 200g/s per bank on WOT. Might be tired MAFs. But also, your accelerator position doesn't go to 100% on WOT. Might explain why. Or maybe you've still got a small leak around the MAFs or somewhere else. Trim looks OK, so nothing major. They're quite balanced also.

I didn't see the kickdown switch activate either, so are you sure you were pushing the pedal as far as it goes? Might be worth carrying out an adaptation on the accelerator pedal, but the kickdown switch is independent of adaptation.

The EGT fault will likely be what's causing the ECU to pull boost. Might be the circuitry, given that the readings look coherent. Either way, it needs to be sorted.

Probably it won't take much to get the engine running nicely.

Also check for oil stains in the bottom corners of the intercoolers, indicative of a boost leak. The boost didn't seem to be tightly controlled, but it's hard to say with sparse data and low requested boost.

[Shoppinit]

I would probably replace the MAFs, DV and N75, and all the vac hoses. Belt and braces.

[Marcin]

I would probably replace the MAFs, DV and N75, and all the vac hoses. Belt and braces.

Thanks Shoppinit!

I went to Audi yesterday and bought some vacuum hoses as my ones look collapsed, just waiting for clips as they didn't have any. I will order the remaining bits and hope for the best.

Also, will look into other issues like kick down and throttle pedal as I did press it all way down; the temp sensor etc.

I hope it's something small and simple as the car seemed OK when it was used last, 2 years ago. Someone put in a new caliper, a new alternator, and a few more maintenance receipts, I guess the engine was 100% then. Whatever happened, it was during 2 years of sitting in the dealer's yard/garage being only moved around the block every so often.

I will work on this, I might pick your brain again at some stage if you don't mind. Thank you so much

[Felix2566]

Did you say your were going to replace the seals between the maf and the inlet? After changing mine it got rid of so many spurious codes.

[Marcin]

Did you say your were going to replace the seals between the maf and the inlet? After changing mine it got rid of so many spurious codes.

Yes I will replace them too

[Felix2566]

Much cheaper than a pair of mafs

[Shoppinit]

I bought some Bosch remanufactured MAFs once. They were pretty reasonably priced and everything was new except for the the body.

[lewp]

ahhh yeah i think i need some MAF seals to, im thinking of going APIKOL ones.

At the end of 4th my traction light comes on and stays on if im WOT and the code it throws is some MAF related codes so im thinking two new MAFs and seals to see how it goes

[Felix2566]

I bought OEM ones, were something like 13£ each. Much cheaper....

https://shops.audi.com/en_GB/web/tradit ... 077133428A

[Felix2566]

You'll need a friend in the the EU to forward it on to you, as they wont post to the UK any more
#brexit

[Marcin]

I went for fresh original seals, and read mixed opinions about APIKOL ones.

Anyway for now I have tons of parts and sensors ordered, hopefully she'll be fine.. exciting times

[Felix2566]

Good work, I'm sure you'll have it sorted and running properly again in no time!