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So it has been 2,000 miles since MRC worked their magic on my car so it was time for them to open her back up again.

As most of you will know, part of their original work involved taking of the inlet manifold and cleaning all of the oily, baked on crap that had covered all of the inlet valves, tract & manifold. By the time they were finished all was squeaky clean and shiny :





The plan was always to open her up again after covering some decent mileage to measure how much build up, if any had re-occurred since, before attempting to cure the problem once and for all.

Doug & the team set about doing so today. The following pictures are a selection of what they found:









To be honest after seeing the original pics of build-up after 20k miles, you could be excused for thinking what has occurred since isn’t that bad,…but when you consider the car has only done 10% of the mileage since…………

As you can see the valves are already starting to become covered again, and if you look at the pics of the inlet manifold, you can see trails of oil that came out of it as the guys turned it upside down – it was literally dripping over the floor!

The guys have since set about cleaning everything up again before modding the car to hopefully avoid the build-up happening again – if all goes to plan I should have the car back on Wednesday



Thoughts and opinions on the findings welcomed…..

Nothing suprises me any more, just hope MRC sort a solution, it will make them a lot of money in the long term !
Shame audi can't be bothered.

So what is their proposed solution?

It's truly amazing how much they have baked on after just 2000 miles....... I look forward to hearing a solution to this. Maybe MRC could make even more money selling there services to Audi?

rob, i think it is what was expected after seeing what caldys looked like after 3k.... it does look shocking and i think none of us like the thought of ours looking like that.. it is a pisser and must affect the performance of the car at some stage. cheers for the pics mate..

Must be that Welsh fuel to blame - too much coal!

Well done for pursuing this - I think we'll all owe you one at the end of this

What is the proposed solution, a better cyclonic separator?

The guys have looked a 3 or 4 alternatives before settling on the current mod. it's probably best for those interested to call MRC directly, at the risk of sounding difficult I dont think its my place to spell it out over the Internet.

Are you trialing the mod on your car,and then going to open her up again to see if it works?

I have a feeling that this is incurable, Lets hope that they do have the solution, The holy Grail it seems.

Gaz - yes the car will go back for a final check but MRC are quietly confident they will/have cracked it.

Sonny - its far from incurable

it may be a false assumption thinking all the oil is from the seperator, this guy raises a good point, and sounds like he knows what he's talking about:

leaking past valve guides, but no mechanism, ie fuel, to clean them...all seals leak...if it's a qt/10000 miles, not bad, but if 1/5 is retained on the valves, look bad
Porsche Cayenne
http://www.mbworld.org/forums/3486352-post35.html

I can't imagine oil vapor depositing so quickly as it passes over the valve (which is very hot), it shouldn't condense, the valve is hotter than the gas...

The interior of the entire RS4 manifold is wet with oil. When the manifold is disassembled, oil drips all over the place. The intake ports are wet with oil, not just the stem of the valve. In a port-injected engine with faulty guide seals, there will be a "lump" of accumulation on the stem on an otherwise clean valve (and port). The accumulation of oil on the upper part of the stem of an RS4 intake valve is simply due to the wiping action of the guide seal - not leaking guide seals. The Cayenne photo does look odd, and that particular engine may have other issues. But considering what the RS4 community has seen numerous times, the buildup on VAG DFI engines has little to do with guide seals. Seriously Arthur, just buy a Bentley CD for RS4 maintenance/repair and spend a Saturday afternoon removing your intake manifold - its extremely educational. Actually, if you just remove the throttle body from the manifold and peer into the manifold with a flashlight, you will likely see one of many little pools of synthetic oil looking back at you.

silverRS4 wrote:The interior of the entire RS4 manifold is wet with oil. When the manifold is disassembled, oil drips all over the place. The intake ports are wet with oil, not just the stem of the valve. In a port-injected engine with faulty guide seals, there will be a "lump" of accumulation on the stem on an otherwise clean valve (and port). The accumulation of oil on the upper part of the stem of an RS4 intake valve is simply due to the wiping action of the guide seal - not leaking guide seals. The Cayenne photo does look odd, and that particular engine may have other issues. But considering what the RS4 community has seen numerous times, the buildup on VAG DFI engines has little to do with guide seals. Seriously Arthur, just buy a Bentley CD for RS4 maintenance/repair and spend a Saturday afternoon removing your intake manifold - its extremely educational. Actually, if you just remove the throttle body from the manifold and peer into the manifold with a flashlight, you will likely see one of many little pools of synthetic oil looking back at you.

I beg to differ...I'm betting the guide seals are a good portion, if not the root cause...the guy made an accurate assessment, I hadn't considered, but concur with after observation...

oil can be blown into the manifold during the EGR valve overlap cycle...

I've already pulled the manifold...20k miles, very mild deposits...
a bit more than the 2k photos above
there was oil in the runners, but very little for 20k miles
I didn't even attemp to clean it...

my M3 also has oil in the inlet manifold...
all cars with a closed loop blow-by circuit do...

it taught me nothing I didn't expect...

judging from my recent test times, I'm convinced it is not an issue...
may be in the long run, but doubt it, I believe it's as bad as it's going to get, and has made no negative impact, imo

Whether the oil is coming past the valve guide seals to contribute to the build-up, should be proven when MRC remove pippyrips manifold for the third time. MRC as far as I believe, are tackling the oil from the breather / cyclonic seperators, so if the build-up has stopped, then the valve guides are not adding to the problem and visa-versa. The amount of oil in the manifold can not have come via the valve guides."Normally" injected engines also have plenty of oil from the breather in the inlet manifold, BUT the petrol mixed-in cleans and prevents build-up.