Ok, i know i'm an idiot for not checking the coolant level. I consequently ran it dry and now the car won't start but the engine turns. I've since put coolant in. What have I broken, what have I done to my xjs.

 

Did the engine overheat? If so, how badly? What the egnine making awful noises?

The non-starting might not have anything to do with the low coolant.

Do you know how to check for spark at the spark plugs?

Cheers
DD

 

In fact the engine sounded like it was missing before it stopped. Perhaps it's an electrical fault. Now she turns over but doesnt fire.Yes I know how to check the spark thanks. Could it be that the coil has burnt out? Cheers

 

I hope it is just an electrical fault, but from what you have said I'd be suprised.

You were running the car with no coolant and it started to give symptoms of missing. Not a good sign.

From personal experience with ex Mrs Translator, 3 cars low or no coolant, red light and red zone and I got the phone calls. All three were deceased.

Fingers crossed that you have only had an electrical meltdown.

 

How much coolant should the reservoir hold. I'm refilling it I put nearly 10 litres in and it's still not full. Plus there is no sign of the level indicator. Do you really think I've killed the motor? I could kick myself for my stupidity.

 

XJS or XJ6??

Capacity, I don't know exactly but if anything like the XJ40 around 13 litres for 6 cyl probably more for the 12. Keep filling.

I hope that you have not killed it. You don't say how hot it got, that is the question.

Also, where did the original coolant go, is there a major leak somewhere, or has it been eaten by the engine?

Mind you after adding 10l I guess you would notice if you have a major leak.

Keeping fingers crossed for you.

 

If you are at 10ltrs and its still not full, or showing some "spluttering" out of the radiator bleed plug hole, you are possibly in deep s&^t my frienbd. The capacity is about 15-18ltrs for a HE V12 DRY, and that means the block drained, which is no easy task normally. The Pre HE is a tad more due to the thicker radiator.

My HE took 18.5ltrs when I refilled it after the engine rebuild, new radiator core, and heater core change, so I reckon it was about as DRY as it couild get.

As Doug asked, "how hot did it get", what year is the beast, did you hear any "clacking" sounds when cracking, a dropped valve insert comes to mind.

Also you must spend a little time to find, or try to find, where all that coolant went to.

Is the oil still looking like oil, or iced coffee, and is it overfull, that could be where it has gone, I hope not.

Is there damp carpet around the console, heater core leaking.

There are many other things, but easy/simple diagnostic steps first I reckon.

The NO start may be the coolant temp sensor (LH thermostat housing), coz if this thing got THAT hot, the sensor may be toast, and that is a "prime signal" sensor for engine starting.

You are saying "what have I done to my XJS", so if it is an XJS, perhaps the "mods" might move it to the other forum to maximise responses??.

 

The engine was not overheating but there was the sound that I thought sounded like the motor was missing. There were no warning lights either. There was a smell of burning plastic before and apparently smoke or steam coming from underneath the motor. Perhaps something has burnt out? Where the previous coolant went I've no idea. There was no sign of any leaks. Thanks for all your advice on this.

 

i have read in a british forum that you should use 50% antifreeze in the water because ist good for the parts. any experience with that on your side?

 

Never use plain water on its own. I believe 50% anti-freeze is the correct ratio for temperate and very cold climates, I always use this formula. Key thing is the presence of corrosion inhibitors in the anti-freeze. Users in the tropics can use water without antifreeze, but must then add corrosion inhibitor which I assume is available in such countries. I remember seeing reference to it in my Series 3 workshop manual