Hello everyone! In the past few days I've been getting the low coolant message and it only appears when I start the Jag in the mornings. I start the Jag up and the light appears, once I start driving within a few minutes, the light goes out. The light does not come back on after I start the Jag at the end of the day. Just filled the Jag up with coolant two months or so ago. Maybe it's just because it's a cold start and everything has to warm up? I'm stumped. Thanks everyone!

- Pilotman

 

One morning before you start the car check and be sure the coolant is at the proper level. If you then start it and the light comes on it is probably the float sticking. You can very gently run the float up and down on it post to clean and free it up.
It is fairly easy to do just don't apply to much pressure.

 

The coolant expands with engine warm up raising the float.

 

Check the tank coolant level in the morning when the engine is cold ... before you start the car .... I think you will find you have a low condition.

The proper procedure (outlined in a TSB) is to slightly overfill the tank (above the filed line) -- the excess will be discharged into the fender waste tank. This should only be done once.

You may have a small leak -- if the level falls again -- make sure you get it checked out as closing issues causing overheating is a major cause of engine damage with the x308.

When you first start the car the fluid in the tank drops further ...until the thermostat opens and the car fully warms -- you could be just at the level where the sensor trips

 

Thanks everyone; I had no idea about the coolant expanding with engine temp, I guess you do learn something new everyday! I filled up the coolant to a better level and the message did not come back on. I could not find the filled line, so I just poured in as much as I thought was needed. It's funny, because there are zero leaks whatsoever. I heard from somewhere that Jags "eat up" coolant... Is that true? If so, that's why the coolant seems to be lower every month.

 

Do you have the manual? The manual has the level.

Is about where the bottom of the opening plastic ends. But -- the proper procedure after working on the system is to fill it above the line -- the car will expel the excess and the car is properly filled.

When working on the cooling system or if the level drops far enough the system can get a small amount of trapped air -- overfilling the tank allows for the little extra as the air is expelled.

They don't use coolant -- I have added a small amount two or three times since I purchased my 02 new.

My normal procedure when I do a coolant refresh is to fill up the system to the filled line on the tank -- drive the car for a few days to purge any air and then fill up the tank as described in the TSB.

 

Hiya,
I've had so many issues with my XKR Coolant - it kept leaking and showing low and finally the pump went...was fine when I drove gently for 3,000 miles round europe but now put in sport and dynamic mode it keeps leaking/burning up... garages can't find anything and say it's common :|

 

It does not "burn up" unless you have a bad head gasket. If your coolant is disappearing, then you have a leak. It might be a slow leak or a leak in the bottom of the overflow tank or wherever. If the garage can't find it, I would get another garage, not because a small leak is important, but because I would figure they were either incompetent or lazy.

If your leaks occur when ddriving hard, i suspect it is something in the overflow recovery system,. The overflow tank is not a waste tank= the engine can recover that fluid once it cools by the vacuum in the system.

 

Yes on my last XJ8 I would get the low coolant light after hard runs & it turned out to be a leak @ the overflow tank like sparkenzap suggested.

 

It is "common" for the mechanics to re-install the hoses to the coolant tank on backwards on my 308 "R" model and some of the the XK's too. Causes the condition you describe and looks like nothing is wrong. The hoses should be crossed in a way that looks wrong, but it's not.

Not sure about your car though.
Vector

 

I've taken it to a different garage today because there's smoke coming out the back when first starting the car for the day....
he did a pressure test and found nothing, but started the car and loads of smoke came out the back.

He's suggested a head gasket replacement for £1,100... I'm not sure what to do! :|

 

It sure sounds like you have a bad head gasket, so what to do is a personal decision based on your ability to change the gasket vs. the value of the car. The quoted price sounds right to me.

 

Fixed 3 coolant leaks already. First was the seal in the cap over the thermostat. A cheap replacement. Later, at one connector of the hoses that runs by the intake manifold. Not too expensive/difficult. Third, more tricky, was a slight crack in one of the 2 anti-return valves in the 'heater matrix' hoses. Replacement was not too difficult, finding the leak was. I still have a small leak somewhere but at this time, can't find it. I need to top off every ~500 miles or so. No biggie, but still important that I find that leak sometime. Note that I did the mistake to OVER fill the top expansion tank. That caused coolant to actually force its way out of the cap. I eventually replaced the top tank with a new one (new cap ultimately) and learned my lesson re: fill at level or slightly above as referred to here. Cheers !