Thick white grease in coolant neck, HGF?
 

Hi I have been away from here since march when my classic wagon lost a fight with a Jeep cherokee :(. Have been holding off spending out on a replacement for a while but went to look at another late model classic for sale tonight with a view to buy. The car was really good nick body wise no rust, no dents, perfect interior, and it ran a treat with no real slapping, knocking, surging, hunting, overheating, exhaust smoke/puffs or anything that would indicate a problem. Mileage is low at 78000, recently serviced with plugs & oil. Its on a 2000my W plate, its a turbo 2000 btw. Anyway so I pull the dipstick and I see a single white fleck/smear which is a drop of water I assume as it mixed with the oil when rubbed. It was small and really white & unmixed so I figured maybe it could have come from the dipstick tube as the car had sat for 3 weeks outside unstarted. I thought for the moment I would give the car a second chance but was a little alarmed. So i wiped and dipped about 3 more times and all i got was what looked like good oil, (it was dark and i was working by torchlight though!). So I pop the oil cap off and its clean inside, not even any condensation mayo and it looke totally clean down the filler chute. Then I pop the coolant filler in the front wing and around the inside rim of the filler neck there is a thick substance which resembled grease prob. about 3/4mm thick all around the top inch of the filler neck, a bit worrying! Also further down the filler neck there seemed to be black spots but i couldn't reach them to see what they were, they didnt look like oil spots as they were very black, maybe rust or plastic flecks. So I popped the cap off the expansion tank reservoir (if thats what its called its sort of up near the turbo above the power steering reservoir, hoping to find it full of gunk so I could walk away safe in the knowledge that it has a failed HG and worth avoiding. Sadly (or is it a good thing I cant decide?) it seemed to only contain dark coloured coolant, no floating oil or mayo that i could see. I stuck my finger in it and it came out clean warm & wet! mmm :) We took it for a good long drive then I pulled the dipstick right after and it had no traces of white in the oil that I could tell but maybe it was so mixed it had turned to proper chocolate milk it was hard to tell! Now I didn't buy the car but I did make the guy a low ish offer for it only £50 off the lowest price he said he would let it go for which he did not accept but as we are only £50 adrift there is a chance he may come back to me as I left him my details and said if he has no joy selling it for more he should give me a call. Now at the time I could not see enough signs of HGF to prevent me from buying but now this white greasy thick film in the coolant filler neck has got me spooked. It was really white like grease not brown or chocolaty colour as i would have expected. So... this is a call for help to the Subaru community tell me if the white grease is normal (i'm guessing not my other car was clean as a whistle!), would it worry anyone else enough to prevent them from buying the car even if there are no other signs of HGF? I think if the guy calls me back I will do 2 things... 1: view in daylight! 2: ask if we can take it down the garage and I will pay for whatever test it needs, (sniffer or compression leakdown i suppose) if I am worried. Would really apperciate hearing anyone elses experiences with HG failure early symptoms etc. to see if this is something that anyone else has seen or experienced. Thank you for taking the time to read this stupidly long post!

Can you do us a favour and break down your post into paragraphs chap, its a bit of a brain fryer looking at all that text.

Head gasket most likely, could pave the way for a nice rebuild.

Erm can't read that lot BUT

When was the coolant last changed?

Has it had a previous head gasket failure?

Does it lose coolant?


The simple reasons for asking, is really old manky coolant can get a bit of a greasey scum build up on the filler neck, this typically ends up in the overflow/expansion tank by the battery as the main tank on top of the engine vents excess coolant off into here. Its more likely to happen on cars that have different brands/types of antifreezes mixed up without proper flushing, or its gone for far too long without a coolant flush/change. The sludge is bits of all sorts, rotting rubber from the hoses and seals combined with other nasties caused by various chemicle reactions going on in there: Manky coolant is acidic and basically eats away at your cooling system components - plastics, alloy, rubber etc.

The same applies if its had a prior head gasket failure, sometimes it difficult to get everything fully cleaned out, and may take a number of regular antifreeze/flush and changes to get rid of any accumulated sludge.

Failing all the above. It could be a current head gasket issue...BUT you have to rule out a neglected cooling system first. If its not losing anything, heater works well and doesn't overheat, I'd just flush and change it.

Coolant should be changed every three years IIRC. If its a different brand antifreeze, always flush everything out with a hose pipe...rads, heater matrix, pipes, engine, tanks etc. until the water runs out crystal clear.

Sounds like head gasket or oil cooler,but don't trust a sniff test it doesn't usually work on a Scooby.

Thanks for the input. He says the car doesn't use or lose coolant, I will have to trust him on that I suppose. It didn't overheat on test, its had rocker cover gaskets in the last 4000 miles but no mention of HG or cambelt for that matter although he said the previous owner assured him it had been done, they all say that though dont they! I wasn't aware the scoob had an oil cooler never found that part? I will wait and see what happens, I wondered if it was some sort of stopleak product or summit who knows. Wont be disapointed if I dont hear from the guy as there was deffo something fishy there although the car was mint in every other respect so would be a shame to dismiss it on something that could be harmless.

Go with your gut ;)

when was the coolant last changed.


I 'm certain this is just manky coolant from improper flushing and intermixed brands of antifreeze

I'm suspicious as I was here 5 years ago with my immaculate 96 STI. I bought it & 2 months later the engine was out having the head gaskets done,not cheap. Unless it's an absolute bargain if in doubt walk away.

If he gets in touch I will go have a proper look in daylight. Thanks for your time guys, deffo needs further very careful investigation. Maybe I have discovered a new form of bacteria and will be given the nobel prize :lol1:

Point taken. Head gaskets are not cheap (labour-wise).

If the coolant has gone acidic, its eating away at them bit by bit, same with all the seals and hoses, so if left something will fail eventually, if not the gasket, something else will (like waterpump seal causing air lock) that will make it overheat and blow the head gaskets anyway.

Unless, if I want to be really cynical: The sludge is reminents of radweld. And classic imprezas are well known for hairline cracks on the radiator end-tanks. Its about the right age for a rad failure...my MY97 finally cracked about two years ago..caught before it lost too much coolant and didn't airlock/overheat, so saved the head gaskets.

If it's thick, white and greasy, it's the headgaskets.

Not always that clear cut Geoff.

My experience of gunky cooling systems dicates otherwise.

I have done a marathon google on this and general opinion is split. There are definately reports of coolant going bad and attacking the aluminium components in particular causing silvery white sludge which it could be. Also people say that black rubbery flakes can come off hoses which I can well believe.

However I also found the following diagnosis description!

"Head Gasket at cylinder top = combustion product in coolant (i.e. you'll see black particles floating in the coolant). "

It does sound suspiciously correct... it did have black bits in it! Like I said if I get a chance I will take a better look and let you know, bummer as the car was lovely!

I only have the one....and it was the baddy.

they can get gunky from condensation alone especially in this weather

my old engine used to build up this grey sludge in the expansion bottle kneck [v3 sti in the 60k miles bracket] and it was not the headgaskets. I thrashed the pants out of it for several years and it never used a drop of water.I always put it down to condensation as i changed the antifreez when i got the car.
Im running a stroker now but the original engine was still going strong.

Very interesting. I would like to think I could spot a headgasket failure immediately and my instincts were telling me the car was fine however it just had this build up of thick white sludge grease right under the coolant filler cap (but not stuck to the cap oddly) that I couldn't ignore, plus black flecks down the neck. Another problem was that due to the shape and length of that filler neck near the battery it was near impossible to see down into the tank and see what was actually going on. It was as if this sludge had either built up there due to rising steam just depositing it there or the water level expanding so much it deposited it there like a tide mark. The tide mark scenario seemed unlikely because of the way it looked, and had stuck to the neck. I wonder if it was just greasy steam condensing & depositing there but where thats came from god only knows, never seen that before not to this extent. Well he hasn't called back and I'm holding out that he will so who knows, we will wait to see if I get a second look or not.

"Greasy steam condensing"?

There is so much wrong with that phrase:
What grease did you, or anyone, put into the coolant system?
If none, where has the grease come from?
How does "greasy steam" evolve? Grease and water have VERY different boiling points......

I have no idea, I guess it must be the headgaskets although previous posters have suggested it may not be? I am not a grease expert thank god! All I would say is that my bro. works on a dealership service counter and once in a while he gets someone coming in saying they either tipped oil in the coolant filler hole, coolant in the oil, coolant in the power steering reservoir is the most common aparantly etc. so its quite plausable why its thick like grease god only knows, to throw in a curve ball... maybe its more waxy than greasy? Lets just end it here shall we.

I see what you are getting at. I knew a lass who put oil in her battery because the alternator was squeaking.......yes, really.

So anything is POSSIBLE.
Just don't hold your breath, ok?

it was something like these pics...

http://www.cliosport.net/forum/showt...unk-in-Coolant

This turned out not to be a head gasket but a reaction between brands of coolant I think the guy said.

A classic is screenwash in the coolant lol

I remember reading on here that a thermostat breaking down will put all kinds of cr@p in the expansion tank. May not be the same cr@p but just adding it into the equation!!