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Coolant leak?

2038 Views 10 Replies 4 Participants Last post by  chermie

I'll try to describe the situation. I've bought my Jag in Feb this year - he's done just 21k miles at the time I bought it. I have changed the engine oil the very next day I bought it, and than changed it agan when I was replacing the tensioners from plastic to proper ones. The mechanic who was doing that told me there was pure water coming from the engine before the oil when he was draining it. He also told me that might be because the car hasn't been used for a loooong time. This was on 1st March this year.

In the mid April the warning message "ENGINE COOLANT LOW" message came on. The temperature gauge was in the middle, but I topped it up with around 0.5L of demineralised water.

About three weeks later the same message came on again. I've checked carefully if there are any leaks from any hoses, I put the flattened carton box under the engine to see if there are any leaks, but I havent noticed anything.

The fact is I've had to top-up another 0.5L, this time I've added coolant leak repair fluid (K-SEAL). We'll see if that helps.

I'm still thinking of that water coming from the engine before the oil - I'm suspecting the head gasket might be the problem, which would be the worst scenario.

I have changed the oil myself today. I haven't noticed anything suspicious, the old oil wasn't milky or cloudy... It looked quite normal.

What else can I do? How can I investigate that further?

Thanks in advance for any tips.
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there's a coolant pipe that runs in the valley of the engine, it can have a slow leak. The leaked coolant runs down behind the engine. It's a hard one to trace.

You're loosing a litre a month? Have you replaced the coolant, and what colour is it, the orangey/pink stuff leaves a dried tell tale if leaking. Also another area is the thermostat tower and water pump, check these places after a run when the coolant is up to temp.
Thank you for your reply Sean,

The water pump has been replaced just around two months ago, I'll try to take a look at that pipe you mentioned. Well, a small leak wouldn't be the end of the world, I just wouldn't want to have the coolant in the engine, that's all I'm worrying about ;)

Thanks again and kind regards.
Hello gentlemen,

I know it's been quite some time since I started that thread, but I didn't have too much time to look at the problem.

I recently went to two different garages in my local area to ask them to pressurise the cooling circuit and try to find any leaks. Both garages have done just that, but they haven't found any leaks :(

When I collected the car from the last garage the coolant was topped up to the very max level. I've done around 360 miles since then, and yesterday the 'Engine coolant low' warning message appeared for about 5 seconds. I have checked the coolant level this morning and over 0.5L top-up was needed. That damn coolant is leaking somewhere.

Any ideas anyone?

Thanks in advance.

Kind regards
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Hi I had a leak from my thermostat tower, as mentioned by Sean, it would only leak under load such as motorway driving and would like yours need about half a litre once a month, it was making the sound deadening on the bonnet wet and when I looked down the side of the thermostat I could see the green coolant puddling on top of the engine, you may have a similar case,worth a check
Thank you very much for the tip Lee.
The thing is that I can't locate any signs of the coolant anywhere :( I've looked wherever I could, I have put the flattened carton box underneath the car - nothing. I think some good indy will need to take a look at that.

Thanks and kind regards.
Hi Peter ,I never had a drip from underneath,I suppose if its a all leak high up in the engine bay it can dry before it reaches the bottom
Hmmm... That actually makes sense. Next time I arrive after the motorway run I'll take a good torch and take a closer look again.

Thanks again for your help Lee.

Are the two pipes on the expansion tank fitted correctly. When they are, they look "wrong" as they actually cross over each other. Incorrectly fitted and you can loose coolant as you describe. I know because mine was a bit like that and the pipes had been refitted incorrectly.
Hello again everyone.

What do you guys think about using something like that:
Leak Detection UV Dye For Cooling Antifreeze System 1 X 25ml Bottle Ring RLD2: Car & Motorbike

It's a "Leak Detection UV Dye" - has anyone tried that? Does it work?

Thanks and kind regards.


I didin't have too much time to do anything about my coolant leak, but today I seem to have located it (it wasn't very hard to do after all).

I'd like to ask you for some advice. I took some photos of the leak - I know they are not very good, but the access there was very limited, I've done what I could ;)

Here they are:
Coolant leak - a set on Flickr

Does anyone have any idea what's leaking there? Do you think it's serious (it looks serious to me)?

The leak seems to be located at the top of the engine somewhere, where the very top wheel driven by the belt is (whatever it is).

Thanks in advance for any tips.

Kind regards.
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