Head Gasket ? - Brown Sludge

Evening all,

I currently have a 1985 MK1 Golf Cabriolet GL 1.6 Carb Auto.  I have had it off the road for around 4-5 months due to a radiator leak. I finally got around to replacing the radiator, and all seemed well.  I decided to take it for a bit of a run yesterday drove to my destination about a 45 min drive, and towards the end, it started losing power. On the return journey, I stopped for fuel as it was well in the red and thought this might have been the problem as the last in that tank would have been old and stale.

When I started the car, white smoke came billowing out of the exhaust, and it pulled away very sluggish I got about 500m, and it cut out.  I lifted the bonnet, and there was oil coming from by the inlet manifold. So I removed the air filter to find it blocked with brown sludge. I then removed the air filter housing and the top of the carb was covered in brown sludge. I left the filter off and drove to a safer place and to be fair, and it drove OK.

Is this as simlple as the head gasket has gone or could there be more to it?

There is also the same brown sludge in the dipstick and inside the rocker cover.

Thanks in advance, your help is much appreciated.

Karl

Does look like water and oil emulsified to brown sludge. Being a carb and not a later GTI I'm assuming it doesn't have the oil heater/cooler above the oil filter that plumped into the water system. These are reknown for leaking internally and giving symptoms of a blown HG.

In the coolant header tank is there an oil slick?

If you've been having to top up the rad perhaps the damage was done when running it too low and over heating?  

Engines that are done for short runs without the engine getting up to temp can have that happen……as it could also be condensate that hasn't gotten up to temp to boil out…. 10 minutes to the store and back aren't good on engines that run 10-15 minutes at a pop.

Briano1234 said

Engines that are done for short runs without the engine getting up to temp can have that happen……as it could also be condensate that hasn't gotten up to temp to boil out…. 10 minutes to the store and back aren't good on engines that run 10-15 minutes at a pop.

Looks like a proper soup rather than the 'mayonnaise' that can collect under the oil filler cap etc from condensation from only ever making short journeys. For it to blow/suck that much up into the inlet system a lot of water must have got into the oil sump.

The other thing that can afflict oil on big block engine is a block breather on the right of the cam cover, This can get bung up with oily gunge and force oil out everywhere but that wouldn't account for the emulisication in this case.

Thanks for the advice.  I'm going to strip it back today and get the head off. what would be the best way the flush the engine to get rid of all the gunk.

Thanks again.

Karl

Petrol will clean it up well but obviously comes with safety issues. . . .

Well I haven't seen it that bad, but for the intermix of oil in the A/F we pull the t-stat and re-tighten, then about 3 TBSP of Dawn Platinum Liquid Dishwashing Detergent in the upper hose to the block, re-fill with water and run it for about 10-12 minutes to clean out the oil and gunk, then a flush and black flush of the cooling system.  If Dawn will clean oil off a baby duck with no harm, then it will work on a engine system.

Usually I have never experienced the af/oil intermix like you have, as it is usually (lots of diesel blown gaskets)
it was the oil port that flipped and pressurised the  cooling system and oil pressure which is higher than the cooling system pressure at idle will go into the cooling system via the head gasket or the Water Jacketed Oil Cooler which is why I don't like those things.

For coolant to migrate into the oil then I would have to suspect the head gasket failure, and it is leaking into the oil via the Cylinders.  It could also be the Valve cover screen is so plugged that your system isn't venting Crank Case gasses and that caused something to give, as well as worst case a cracked piston wall failure.

A/F on the crank bearings is more of a concern to me, but I think that a tear down and inspection is warranted.

If you have the water jacketed oil cooler and it is over 6 years old, I would go about replacing it and the o-ring.

If the dip stick is mucky, then I would suspect a more catastrophic failure…. just my thoughts on the matter.

And Dawn Detergent is less explosive, less costly, damaging to plastic parts, and washes off with water.
 

that amount of oil thru the breather system suggests its either overfilled or partially blocked breather system.

make sure the dipstick guide tube is correct for the age of car/dipstick as theres a couple variants.

remove the rocker cover and check the breather mesh is clear, once they clog up its a real mission to clear up fair few tips out there though.

if the head gasket has gone between a coolant and oil channel you really know about it, the inside of the cylinder head will be completely filled with mayo. been there, done that