Hi all, I'm on the market for an Octy SW 130PD, and while I wait for end-of production discounts, I try to keep my high-miler A6 TDI 2.5 (185K km) in good shape... :P

while browsing on the net for TDI infos, I run into TDIclub.com, with these instructions on how to clean the intercooler...

http://www.tdiclub.com/articles/Intercooler_Cleaning/

foreword: I bought the A6 used with 60K km, equipped with a KN cone filter, that I removed shortly after, since perf. gains were negligible indeed...

well, my car has 185K kilometers, and lately wasn't running too well...hesitancies, stumbling when cold, MPG worsening, on very cold days even starting up quite roughly with idle swinging like crazy.....

so I think, what the heck, let's check this intercooler thing....

I remove the airbox and indeed I see the EGR hose entering the intake duct....lots of black oily gunk is already seeping off the connector....mmmmmmmmm :eek:

....2 jubilee clips hold the big rubber hose connecting intercooler and alloy intake manifold .....I easily remove it....

OMG, I can hardly believe what I'm looking at.... :eek:

GUNK!!! EVERYWHERE!! LOADS of it!!

....in some spots there are thick ondulated layers of greasy black deposits, up to 5 mm thick!!!

I look inside the manifold, and the situation is even worse...

so I'm on a crusade now.... ....I remove everything, all the hoses to and from the intercooler, and the intake manifold.....

I first cut through the layers with a large screwdriver, then I use some hard-bristles brushes... then I soak all in degreaser for a while, running a bottle brush in&out the intake ducts....OMG, soooo much stuff coming out, they were almost clogged!!!

I now can see the shiny alloy underneath...so rewarding!!

I also take the chance to scrape away a lot of deposits inside the head intake holes...so much black dust is being blowed out with the air compressor, that I have to wear a mask, or I'm gonna get lung cancer....

the most clogged was the intake manifold, followed by the intake duct...the intercooler was dirty , (a cup of sludge was pooling at the bottom of the cooler!! :eek: ) lbut luckily not encrusted to the same extent....phew!!

I then rinse and dry everything with the air gun, very handy and effective tool indeed...

I reinstall everything, , making sure this time to keep the oil vapours recirculation hose OFF the system...no more soiling my intake, thank you....

I seal the connection, and prolong the vapour hose from the valve cover down to the bottom of the car....

finally everything is back in place...it took me 5 hours!!with some trepidation, I start the car....

WOW, transformed...!

all the hesitations are GONE, idle is perfect, take off with cold engine is now super-smooth like it never did before !!! (I bought it used)

it now hits 125mph in a breeze, and pick-up from low speed in massively improved.....

will check MPG soon of course, I bet they will improve as well...

what to say...the best 5 hrs ever spent on a car......my A6 is now transformed, thanks to this forum for the infos that triggered my quest...

if you have an high-miler TDI, do yourself a BIG favor, and have it done (or, even better, DIY) !!

Ricky

Excellent! Well done on that Ricky, sounds like quite a chore, but worthwhile and satisying.