brown sludge in header tank.... Not H/G!!!!?

just recently done the head gasket on my 86' CC cab, as it had the same brown sludge in the header tank, oil dipstick and oil filler cap….

so i pulled the head, and swaped the head gasket, couldnt actually see any defects in the old head gasket, i also checked the head & block for flatness, as they sometimes warp etc… no warpage.

i also changed all the belts while i was there re-set the timing etc… anyway finished that on friday, and just topped the oil up before i started to use it a little over the weekend, i also drained the coolant afew times to get all the oily crap out of the block & coolant hoses, then it started to run clearer coolant on sunday & monday,

used it for work today and the oil lights been flickering on corners which is weird as it was on the full mark 2/3days earlier, anyway the oil light and buzzer was on for the last bit on my way to work, so i knew somthing was up…

let it all cool down and once agian thick brown oily gundge in my header tank, and hardly any oil in the engine, there was again brown foamy sludge on the dipstick and the same under the oil filler cap & header tank cap…

seems like the head gasket has gone again…. but i REALLY doubt it.

theres afew threads on here, as ive searched, saying there is somtimes isues with the water pipes going thu the oil filter head, ie they leak??

this GTi has no oil cooler, but does have at lest 2 pipes going into/out of the oil filter head!

is it possilbe that theres a gasket/aluminum corrosion problem in there??

judging by the ammount of oil its used in the last few days this is unlikly that its water getting in to the oil, more like oil getting into the water!!

and really do doubt its the head, although without getting it machined i cant be 100% of flatness, so im more like 99%sure its not the head / head gasket…


anway ive got home in it after topping up the oil… ill go out an check the oil level once its cooled down, there should be some inbetween the marks, but i know one thing for sure the header tank will be full of brwon crap.


cheers for any help

alex.

the oil fither housing has a oil to water cooler, the idea being that water heats up faster than oil, so the heat to start with goes from the water to warm the oil, then when pressing on the heat goes from the oil to the water to cool the oil... the porb is these are well known for giving up and allowing the water and oil to mix... i think this will be whats happened in yours. junk the oil to water cooler and fit a proper oil to air cooler from the earlier GTis and spend an age cleaning it all out again.

as above, have another look at the oil cooler housing, if it has 2 coolant pipes going to a blocky thing between the oil filter and the sensor housing, it has a water-> oil cooler. 1st step take the coolant pipes off it and bridge them together, then flush the coolant system. Run it for a day or so. if oil doesnt return you know its the oil cooler, if it comes back the issue is elsewhere.  also a giveaway if oil starts coming out the oil cooler

to flush it, pop as many hoses off the engine and flush it with a hosepipe every which way.  put it all back together then fill with plain water, and half a cup of washing powder. run engine till it gets warm, allow to cool then hose flush it again. repeat till the oil is gone

rubjonny said

to flush it

Good advice , just don't try this on your drive or block paving  :wink:  

coolio, ill try re-routing the pipe work to bypass the oil filter head thingy….

hopefully that'll sort it!!

cheers
alex.

M7R said

the oil fither housing has a oil to water cooler, the idea being that water heats up faster than oil, so the heat to start with goes from the water to warm the oil, then when pressing on the heat goes from the oil to the water to cool the oil… the porb is these are well known for giving up and allowing the water and oil to mix… i think this will be whats happened in yours. junk the oil to water cooler and fit a proper oil to air cooler from the earlier GTis and spend an age cleaning it all out again.

Yep!

Never quite know why they felt they had to change the cooling system?
But i guess they had their reasons :dontknow: