Cold

hi there, 1st post here, i recently bought a Audi A4 B6 1.8T, 2001, and had noticed after a few weeks the water level was going down quite fast, i found the leak is coming from the back of the head somwhere on the bulkhead end near where the temp sensor is, however im still not sure where the leak is coming from, as far as i can tell its not where the sensor push's in, anyway, ill deal with the later, my main problem now is that as i was taking off pipes to get a better view of where this leak is coming from, i notices the breather pipes were badly sludged up, to the point where the rubber t piece was totaly blocked, and fell apart when i removed it as the rubber had become softer, so after some more research ive found out that this is quite a common problem and can clog up the valves and stuff in the engine, i decided that to see how far the problem had gone i would take the rocker cover off and have a look, surpisingly its not what i expected, its not exactly pritty, but i cant see any sludge in there, im attaching some pics, what id like to know is, what do u think? is there a way i can clean it without pulling the head off, does it even need cleaning? ive read in a few places about putting diesel in with the oil and running the engine on idle or at certain rpm's for diffrent periods of time, depending on where i read it, lol, but is this really advisable? or neccersary, if the sludge is only in the pipes, would it be ok to just clean them out and put it back together?, i want to take the inlet manifold off anyway, as i could do with a clean, "whats the best stuff to clean alu at home? i used o work somewhere where we cleaned heads and rocker clovers by putting them in a tank of acid for a few days, but thats not realy feasble, what else brings alu back to new "or almost"", anyway u can see where im going with this, i want a nice clean engine, but without having to take the head and or engine out, but, But!, i would i it would really be worth it, im a competent diy'er, but ive not took a head off or changed a changed a cambelt in years, and id rather not have to make uneccesary work for myself, paying a garage to do the work just isnt affordable in my current situation, plus, theres the old saying, if you want something done right, do it youself, and i enjoy this sort of thing, anyway, ill shutup n let you answer now, whats your prognosis fellas, thanks in advance.

Chaos

The coolant leak is probably coming from the coolant flange there are writeups on replacing it on the internet, as for the sludge it dosent look bad looks like any other 1.8t that ive seen with the valve cover off, replace the rubber pipe it gets soft from the oil and you can attempt to clean the breather pipes best way would be to remove them and run brake cleaner through them.

K04-S4

Recommend replace all crankcase breather pipes including PCV. As they have aged, they tend to crack and break if you play with them. Not an easy job with intake in place but well worth it to your engine!

Cold

thanks will check out that info on the coolant flange, i figured looking through ETKA that it might be somthing there, will also replace all the non metal breather pipes and joints, as K04 said, ive already split one of the plastic bends, and the rubber t-piece has fallen apart, so definatly needs doing, glad that my messy head isnt much worse than anyone elses, i still think ill flush it with some cheaper oil to try and clean some dirt out with a new filter, is there anything i can add to that oil to help it clean the engine out abit without hurting it at all, afterwards i will put some high quality oil in, and another new filter, what brand/type oil is most recomended, i knwo it has to be fully synthetic? does it need to be for the flush, oil will it be worse off if theres and non-fullysynthetic left in the knock and crannys? also, any ideas for cleaning alu parts to look like new? diy style, lol

wanthema

you just got the car am i right? you dont know exactly how the previous owner treated the car, so just to be sure and safe you might want to do all the precautionary checks like changing the oil +filter, air filter, cabin air filter, fuel filter, timing belt, and transfer and diff fluid. depending on your mileage you gotta check whether your car is due for a tranny fluid replacement etc etc..

what u might want to do if u want to save cost and not damage your engine is, when you are doing your oil change, put some additive such as seafoam / engine oil cleaner with the old engine oil that you have in the engine, let the engine idle for a good 5-10 mins not rev'ving the motor, then drain it out. cleans out most sludge built up in your engine.

After that, if you want clean your engine some more, i suggest you do the following steps since you can clean out of your engine so much on the first try, do it again ensure there are no leftovers.
1. pour in (regular oil) this wont hurt your engine while idling.. about 2-2.5L of oil will do.
2. idle the car for 5-7 minutes. (do not rev the car because ur using regular oil and not synthetic, and also not enough oil and you will do damage rather than good)
3. turn off the car and drain it.. you'll see the clean engine oil that you put in turn dark and sludgy.
4. repeat step until you see some distinctive color (brownish yellow) from draining the oil on your oil catcher.

End result, take out your old oil filter and replace it with a new one. and put in 0w-40 mobil 1 synthetic. 4.5 L of engine oil is what your engine needs.

Seafoam works great with cleaning stuff like the engine and fuel tank, but dont use it often, once every 1-2 years is good enough to keep the engine clean.

Cold

thanks for the tips m8, was sort of going to do all that anyway, but needed a suggestion on addative, and weather i could get away with non synthetic for flushing, also didnt know about the tranny oil, will look into changing that, i know this car has not been looked after well in the last 2-3 years, and its showing, ive ordered all new oil breather pipes, a new coolant flange, a new thermostat housing, as the seonsor had corroded away, and the platic that holds its clip in had snapped away, new thermostat, obviosly, all new seals for there assosiated flanges and quick release pipes, already took the inletmanifold off and cleaned that up the best i can, soaking it in degreaser overnight, also cleaned up throttle body the best i can, injectors and fuel rail ect, think the snesor in inlet manifold needs changing, is that a air temp sensor? AVJ Engine btw, heard its rare and sought after, but can anyone tell me why?