5.0 HC Chimeara loses it's cool !

[SGILLOTT]

I have my Chimeara booked in for the third time with one of my local dealers to have a look at the cooling system. The problem appears to be a very rapid loss of coolant out of the expansion chamber with no obvious signs of exit. From nearly full to no water visable at all in the expansion tank in under 50 miles. The system has been pressure tested by the dealer who reports no problems. I've started the car and run it for a while checking all connections for signs of leaks etc. Having read The Bible I have no further ideas. Has anyone experienced this or have any ideas I can pass to the garage?

[GreenV8S]

I have my Chimeara booked in for the third time with one of my local dealers to have a look at the cooling system. The problem appears to be a very rapid loss of coolant out of the expansion chamber with no obvious signs of exit. From nearly full to no water visable at all in the expansion tank in under 50 miles. The system has been pressure tested by the dealer who reports no problems. I've started the car and run it for a while checking all connections for signs of leaks etc. Having read The Bible I have no further ideas. Has anyone experienced this or have any ideas I can pass to the garage?

Could it be a heat-dependant leak? That might not show up during a pressure test when everything is cool. Other than that, hmmm very strange but not good!

[RCA]

Funny that, Mine seems to like its coolant as well, Top it up every few days!!!, Always have done since I have had it, over a year!!!, Performance is fine, runs great and the oil is ok aswell!, Temperature gauge works fine and the fans cut in when they are supposed to. Can't see any visable leaks either. Does not help I know, but you are not alone!!!!!

[angusfaldo]

Is there anything left in the tank at all after coolant loss?

Normal level is quite low in the tank - is there a chance you're overfilling it and when up to temp just dumping out the excess?

Does the engine overheat after the 50 miles?

AF

[Leadfoot]

The expansion tank should be topped up to 1/2 full (I'm talking about the serpantine engine). Any higher & there will be no room for fluid expansion, the tank will be overfull & vent out of the cap - it also sets up a syphon action & hey presto even more fluid has gone.

[Scoobysnack]

Had an airlock in my old Chimaera where I kept topping up the expansion tank but not squeezing the hoses to get the air out.....

Eventually when the rad started leaking the car showed signs of getting too hot.

J

[soddy]

Many possibilities including;
Leaky Liner
Pourous Head
Pourous Inlet Manifold

The list goes on!
You need to determine where the coolant is leaking. If it is a liner then there is likely to be a "clean" piston. If it is in the inlet tract or head then similar is likely ... you can check for head gasket leaks at the back corners ... or inlet manifold leaks on the valley gasket seal .. but ulimately you will probably have to get the system pressurised when hot and a check for hydrcarbons in the water or water in the exhaust.. but as others have said .. it may just be a leaky hose at high temp or pressure.

[trefor]

Nearly full expansion tank to no water in 50 miles is helluvalot of coolant to be losing out of the overflow (under pressure) or from a leaky pipe without noticing drips on the floor etc. I assume you've checked the oil level isn't going up?

I'd hazard a guess that you've got a leaky head gasket or worse a cracked head. The water is moving from a water jacket, across the leak in the gasket and out of an exhaust manifold galley. That way you'll not notice the water vanishing.

[BLUETHUNDER]

I had exactly this same problem on my 4.6 range rover,after having both head gaskets done and a further dye test done to ensure the problem was fixed.I found out my problem was still there.I knew then that i was suffering from a common problem on early new shape range rovers,a pourous block.The only cure was a brand new engine.I do hope you havent got the same problem but it sounds to familiar.If i was you i would get a dye test done before you go any further

[SGILLOTT]

Thanks for all these tips folks, I'm determind to get it sorted one way or another so I'll see what the dealer makes of these suggestions.

As ever it's very helpful to know that people take the time to respond to each others postings.

[the dodger]

Does it overheat after your 50 mile trip? It seems not all enfgines are the same and require different amounts of coolant. If it doesn't overheat then maybe you're overfilling the expansion tank?

[SGILLOTT]

There's no signs of overheating but now I know the levels are going down I don't let it run for long without checking. I appreciate cars have different levels but the local dealer tells me at least some water should be in there!