Is this serious? Or did I do something stupid?

[Gixer]

You tried a block test yet?

[StottyZr]

Shadows said:

Easy to find out if headgasket's goosed by a milky residue in either the oil or coolant. First thing I look out for when buying a used car.

Not if its been k-sealed as described.

K-seal is a brilliant and horrible invention, I bought a Zr recently that had no signs of hgf until after 3hours of motorway driving and the car began to overheat on b roads. Turns out it had been k-sealed which stopped the oil/coolant mix and most of the signs. It would appear a tiny amount of air was being forced into the coolant system which caused the coolant to over pressurise and push past the cap. Which in turn displaced coolant and created airlocks which caused overheating.

k-seal is a little bd and I always check for signs of its use when looking at a car now.

[Shadows]

StottyZr said:

Not if its been k-sealed as described.

K-seal is a brilliant and horrible invention, I bought a Zr recently that had no signs of hgf until after 3hours of motorway driving and the car began to overheat on b roads. Turns out it had been k-sealed which stopped the oil/coolant mix and most of the signs. It would appear a tiny amount of air was being forced into the coolant system which caused the coolant to over pressurise and push past the cap. Which in turn displaced coolant and created airlocks which caused overheating.

k-seal is a little bd and I always check for signs of its use when looking at a car now.

Well there was plenty of it in my dad's rover 75 even with K-seal.. But agree it's a horrible yet amazing creation. Kept the car running for a couple more years anyway.

[Steviesam]

Shadows said:

littleredrooster said:

Only true if the gasket fails between oilway and waterway. Oil and water mixing will form the telltale 'mayonnaise' somewhere.

If it fails between cylinder and oilway, oil will go black very quickly and may blow out of breather or dipstick.

If it fails between cylinder and waterway, it will pressurise cooling system and blow it past the pressure cap, until it cools down then it will suck it back into the cylinder and start in a cloud of steam next time around.

I've had all these combinations in my time.

Learn something new all the time ..

My 528 was losing water from the back of the block via the headgasket, so I had no milky oil either. Just dripping down the block.

[Smanks]

Shadows said:

I have never seen white milky liquids in oil and coolant from short driving, white bits from residue's sure. Any links, technical guides / readup's?

No links, but I've seen it on more than one car, all of which had perfectly fine head gaskets. A decent drive will clear it out if it occurs.

[eltax91]

OK chaps. Just traveled 2 and a half hours back home, THEN LET THE CAR COOL DOWN and then took a few pictures. It did need a top-up, but then I dont know how much i lost in the dark last night!





I should add, I have cleaned this gunk off the cap in the past. So, HGF? Or a good indicator the coolant cap needs replacing?

[KTF]

When was the last time that the coolant was drained and refilled and has it been topped up/refilled with the correct spec?

[eltax91]

KTF said:

When was the last time that the coolant was drained and refilled and has it been topped up/refilled with the correct spec?

The car has always been serviced by a specialist before my ownership (and since). Previous owner was not a car guy, but history shows evidence of a rad change last year, and I assume G48 coolant being used.

Since I've owned the car, all my topping up has been with G48

[Sump]

If they properly pressure tested and you were still losing coolant then this means the system has air and hasn't been properly drained and refilled.

You don't just lose coolant for the lulz. It leaks or there is air in the system and slowly the coolant level is dropping as it fills into the system and leaves the expansion tank.

You need to have the system drained and properly refilled and bled to rule out any genuine coolant loss and therefore any leaks.

[Shadows]

Sump said:

If they properly pressure tested and you were still losing coolant then this means the system has air and hasn't been properly drained and refilled.

You don't just lose coolant for the lulz. It leaks or there is air in the system and slowly the coolant level is dropping as it fills into the system and leaves the expansion tank.

You need to have the system drained and properly refilled and bled to rule out any genuine coolant loss and therefore any leaks.

+1

[Benj1984]

Shadows said:

+1

Just get a chemical block test carried out. It's a 5 min job and will tell you straight away if the head gaskets gone.

It could be an air lock? Or if it is a leak I'd take it to somewhere better than the place you've been using to have it checked out, because frankly, it's basic stuff.

[Benj1984]

Targarama said:

These cars normally need a cooling system refresh around 100k miles - radiator, expansion tank, water pump, main hoses, thermostat and expansion cap. Have these been replaced in the car's past? If not I suggest getting the whole lot done. Read up about the 5 series straight six cooling system and you'll find lots of forums telling you this.

I never understand this kind of forum scaremongering. No car suddenly needs its whole cooling system changed at 100k. You service it regularly over its life and replace parts as they wear and start to fault.

[Sump]

Benj1984 said:

Targarama said:

These cars normally need a cooling system refresh around 100k miles - radiator, expansion tank, water pump, main hoses, thermostat and expansion cap. Have these been replaced in the car's past? If not I suggest getting the whole lot done. Read up about the 5 series straight six cooling system and you'll find lots of forums telling you this.

I never understand this kind of forum scaremongering. No car suddenly needs its whole cooling system changed at 100k. You service it regularly over its life and replace parts as they wear and start to fault.

+1.

It stems from over the pond scaremongering.

[Skyedriver]

K Seal - £10/bottle worth every penny
The speckles though are pinky
Volvo 940 engine had a hydraulic lock due to sucking so much water into the cylinders - 40k miles later not a drop of water being used

[Nigel Worc's]

Eltax.

Sorry mate, hadn't been around much lately, so missed this thread.

Stating the fking obvious here I know, but this is either nothing to worry about, or could write the engine off, (we've just had to replace the engine in my "to be" son in laws E39 525i because he cooked it), coolant is as important the these engines as oil.

Get it over to BM Euroservice, get it diagnosed, it'll only cost you about £50, but could save you £1500 plus to put a second hand engine in it.

A good normal garage mechanic is a fantastic friend to have (you've met mine), but mine would despatch me to BM Euroservice with the problem you have, if he couldn't see the issue, as he knows how temperature sensitive these engines are.

http://pwebdesign.brinkster.net/bmeuroservice/cont...

[steve_bmw]

No matter how far you have driven it you should still be able to take the rad cap off without the water bubbling out, you should get a small release of pressure then remove the cap, if its bubbling out its getting pressurised, or over filled.
If the water is boiling and trying to force it's way out of the expansion bottle something is wrong.
Could be something as simple as a stuck valve in the cap.

[Nigel Worc's]

steve_bmw said:

No matter how far you have driven it you should still be able to take the rad cap off without the water bubbling out, you should get a small release of pressure then remove the cap, if its bubbling out its getting pressurised, or over filled.
If the water is boiling and trying to force it's way out of the expansion bottle something is wrong.
Could be something as simple as a stuck valve in the cap.

You are joking ....... right ?

Or do you just like to see people scalded ?

Jesus, you see some crap written on forums !

Google boiling point of liquids versus pressure/altitude.

[Shadows]

Nigel Worc's said:

You are joking ....... right ?

Or do you just like to see people scalded ?

Jesus, you see some crap written on forums !

Google boiling point of liquids versus pressure/altitude.

, I had a focus in which the plastic wind on the coolant box had dwindled away. Sat in traffic with high heat, the coolant blew. I went to look at the engine and could feel the extreme heat under some thick soled shoes to the point where I had to move. Not a good idea taking the pressure cap off .

[Benj1984]

Nigel Worc's said:

steve_bmw said:

No matter how far you have driven it you should still be able to take the rad cap off without the water bubbling out, you should get a small release of pressure then remove the cap, if its bubbling out its getting pressurised, or over filled.
If the water is boiling and trying to force it's way out of the expansion bottle something is wrong.
Could be something as simple as a stuck valve in the cap.

You are joking ....... right ?

Or do you just like to see people scalded ?

Jesus, you see some crap written on forums !

Google boiling point of liquids versus pressure/altitude.

In my experience steve_bmw is correct, where modern cooling systems have an expansion bottle and a pressure cap, the cap has two phase, one to release the pressure then one to remove the cap. This doesn't work on jap cars with rad caps and reservoirs, but on most European stuff, you should be able to release the pressure and remove the cap. If coolant is boiling out of the bottle after cap removed then its under pressure, either from an air lock or from cylinder combustion pressure.

[steve_bmw]

Nigel Worc's said:

You are joking ....... right ?

Or do you just like to see people scalded ?

Jesus, you see some crap written on forums !

Google boiling point of liquids versus pressure/altitude.

No I'm completely right, you should be able to remove the explanation tank lid without water coming out.
Japanese cars have a pressurised radiator cap and an expansion bottle cap, you can't remove the metal cap on the radiator but you can remove the one on the expansion bottle.

BMW has only one cap, on the expansion bottle,

Your knowledge is floored.