Cooling Airlocks and Water Loss

Head gasket.

Steve

So where's it going and why no performance/efficiency loss?

Simon, it could be going directly into a pot & burning off.

Easy way to check, take out the spark plugs, if one is washed clean, there's the culprit.

I dont know that engine, so i could be wrong, but it's easy to check.

:)

Any damp inside the car? Heater hose/matrix possibly. Although at 2-3 litres a go, you probably have a mobile fish tank by now.

If it's the cylinder head gasket you should be able to test for gasses in the coolant. Most garages have a tester that will do this.

If you want to get one for yourself:

Just got back from the cinema [1] and pulled all six plugs - none of them are washed. In fact they're all a perfect tan colour.

It's a simple engine really - so pretty basic. Just everything on it is pretty big.

My Rover's K series engine has a gone gasket (proved by gas test in the coolant) but there's no loss of performance. Still starts and runs like a dream.

I think that's going to have to be done.

My other approach is to use some "stop leak" type stuff and see if the loss of coolant stops.

Was there any visible coolant or oil contamination?

Well, thats sorted that bit then.

I once had a Range Rover 4.6 that is infamous for liners slipping inside the engine, usually writing off the car, i was getting major coolant loss & it looked like the usual suspect of cracked block/liners. The only thing was there were no other symptoms of it (top hose pressurised all the time running, or chug in the coolant)

Turned out to be one of the hoses to the RH bank of cylinders was holed, the water just jetted away from the engine & when you had it on idle it didnt do it.

The only clue was a bit of coolant staining on one of the chassis legs.

On the top of the engine, it gets so hot that any dribble evaporates instantly & left virtually no stains.

I rather fancy that!

Please don't do that on an XK engine. You stand a reasonable chance of doing permanent damage. If you're not already a member of the JEC, consider joining. They have an excellent support network including the loan of some of the specialist Jaguar tools. Also bear in mind that with the XK engine advice in the handbook to only add oil to the engine when the engine is cold should be followed, damage can occur if cold oil is added to a hot engine.

Or any other engine, unless it's in something you are going to scrap soon.

Chris

How?

I am a member - I'm not impressed, the forums have been down for the best part of the year, it worked out cheaper and more effective to buy the special tools I needed than use the tool loan scheme and the editorial has a definite "whiney" air.

That's bollocks. The factory manual or original handbook make no mention of that.

In fact it just tells you to wait one minute if the engine has been running to allow the oil to settle before checking and topping up if necessary.

It also recommends the engine oil is changed with a /hot/ engine and makes no reference to waiting for it to cool before refilling - the same as every other engine I've worked with.

Why?

It can clog things it's not supposed to, but the biggest issue on a vintage engine is it makes welded repairs to the head or block far more expensive.

There really were people who used to put an egg in a rad' to try and cure a leak.

Try running with some form of container connected to the overflow. A small head gasket leak can pressurize the cooling system beyond what it should be and force out coolant. Without effecting the running.

Rover - when they were independent and also in BL days, so concurrent with the XK engine, used to recommend Barrs Leaks.

I would also be interested for some conclusive evidence of this, sounds like pigshit to me.

Just get the oil all nice and hot on the cooker first...yeah right.