This can't be good... (warning 56k)

[sigma]

Put a catch can in my car a couple of weeks ago so decided to check it yesterday....

Previously clear lines had gone a funny colour...



Overflowing (oops) with something resembling oil...



Milkshake anyone?







And under the oil filler cap... hmmm.



So does this look like the classic symptoms of a BHG/cracked head to you guys? I mean thats what I'm thinking looking at the catch can, but the filler cap looks pretty clean and so does the coolant. And today the return line on the catch can has some foamy cr*p in it. Comments please!

[Distrb]

Re: contents of catch can.

I'd expect that to be the case... hot air contains alot of moisture, so when the air cools and heads out the breather filter, you're left with oil and water in the can... which looks like that when it mixes....

how long has it been since you emptied it? looks like a while!

[pjay]

dude.. someone shat in your engine!

[Mr Revhead]

how is that hooked up? vented at all?

bigports are well known for lots of oil in the head.
looks like its spitting oil into the can which is mixing with all the water.
i was empying mine of 500ml of water a month on average.

[sigma]

Sealed can, line from rocker breather to can to plenum.

I knew the oil was gonna be off-colour and I shouldn't put it back in the engine after getting caught in the can, but I wasn't expecting this thats for sure.

[sigma]

how long has it been since you emptied it? looks like a while!

Maybe 2 weeks at the most?

[Mr Revhead]

the way you have that set up itll suck oil/fumes from the head and dump the heavy stuff in that can.
theres quite a bit of water vapour in an engine, thats mixing with the oil.
the result is that gunk.

[sigma]

the way you have that set up itll suck oil/fumes from the head and dump the heavy stuff in that can.
theres quite a bit of water vapour in an engine, thats mixing with the oil.
the result is that gunk.

That was the idea behind doing it like that, as AFAIK the bluetop doesn't have a PCV valve(?) and i figured ventilation was a good thing.

So you reckon I should block up the return on the plenum and just have the line hanging down to the ground?

[rollaholic]

whats the oil in the sump like? doesnt look like a headgasket problem from those pics, its easy enough for a garage to test though if you have any doubts.

[varix]

Lol

[TrouserFxGt]

do lots of short trips?

[RS13]

I had heaps of that milky gunk in and around the breather tube on that black AE92, but non under the cam covers.. I did a lot of short trips, its' just moisture mixing with oil, no biggie. I went for a decent thrash over to Akaroa, it pretty much disappeared aside from traces in the pipe.

[Mr Revhead]

from what i can see you have it going:

cam cover
sealed can
manifold

some of the oil and vapours will be trapped in that can
any water vapour will condense in there as that can will be cool, and will remain relativly cool. so oil + water = that mess you have there.
it will also be sucking vapours and any over flow from that tank straight back into the engine intake.

how thick is that fluid? it looks mostly oil. which brings up several possibilitys

1: typical bigport oil collection in the head under high revs
2: ring blowby pressurising crank case and head, blowing oil out the hose
3: something else iv forgotten

[Truenotch]

Looks like a mixture of fumes from blowby condensing and the oil from the breather blowing into the can.

I think that the majority of 16v 4age smoke is made from oil going though the breather and being re-burnt .... well that and valve stems.

What does the car run like? How many K's and has it been re-built lately?

[sigma]

200,000 kms, bottom end was rebuilt a bit over 10,000kms ago, but the head wasn't. Smokes quite a lot with the catch can on, have since blocked up the return on the plenum and vented the can to air. Didn't cure the smoking problem.

Side note, the engine likes to foul number one cylinders spark plug after being revved hard. I'm starting to think the new rings haven't bedded in properly, as its making a bit much smoke to just be the stem seals. Other than that the car seems to run ok... when its not just firing on 3 cylinders.

[Truenotch]

So the whole bottom end was re-built, with new rings? Does sound a lot like glazed bores mixed with some extra oil from leaky valve stems... Maybe.

Did you do the run in on it?

[Dell'Orto]

Yeah sounds alot like glazed bores if it was a fresh rebuild. Easy fix though

[slighty_sykotic]

Yeah sounds alot like glazed bores if it was a fresh rebuild. Easy fix though

sand into bores?

How would you cure it?

[Dell'Orto]

Well thats an option, though usually getting the block honed is the better way
You can buy a glaze breaker hone from Powerbuilt, which looks to be just a drill powered hone.

[Truenotch]

That gritty Jif stuff / valve lapping slurry + glazed bores + running engine = mint

Try it, I dare yah!