Disappearing coolant!

Hey guys, very much hope youre all safe and well =)

Right, got an annoying issue! Its a Meglio but im guessing it would be a universal issue, the coolant disappears at a fair rate, ive pressure tested the system, and done all the usual checks like the oil and so forth, but i cant see anywhere where its going! there are no horrible signs, car doesnt overheat, there is no steam from the bay, or smoke from the exhaust, but it drinks enough after every drive to make it almost disappear from the header tank, also have a brand new airtec header tank but the problem was there with the previous header tank also, so i have no idea where its going, and the Renault green stuff isnt the cheapest just to keep chucking in haha

any help would be much appreciated =), thanks guy

oh and ive bled the system again too just to make sure
 
If you can’t find a leak, maybe it’s time to do a compression test, or test the remaining coolant for hydrocarbons
 
cheers bud, might see if my mechanic can get me in asap =), having a new engine in it next year but would still like to get it sorted =))
 
just out of curiosity, how much would a head gasket change set me back nowadays? usually do most of the stuff myself, but literally havent the time to do it at the mo =(
 
Honestly I’m not even sure. I’ve not seen anyone really have an issue with them on the Clio’s. I just can’t think of anywhere else where you’d lose coolant.

I guess you could say at least 300 quid cus you’d put a new belt on when you did it.
 
I had a similar issue last year, pressure test showed no leaks, thermostat was new, hoses all looked good but the car would literally dump the coolant when it got up to temperature. Turned out to be a tiny hole in the radiator, bottom rad hose and the short 90 elbow under the expansion tank. Replaced the lot and it's been fine since. Mine's a stock engine though, not a Meg engine.
 
thanks for the reply guys, appreciate the input =)

@Foxspeed, ive pressure tested the coolant system, but not the cap, the cap is on the new header tank i got from airtec last month, but always worth a check so ill look into how i do that, although it happened when i had my old header tank also

@Helpimonfire, i shall take a lok at that tomorrow, thanks for the suggestion =), the rad was new last year from airtec, but thats not to say it has had alittle damage since fitting it, although i would have hoped the pressure test would have pointed me to that, but i could not have been looking either haha! thanks dude =)
 
Guys, I'm gunna write a reply here that's gunna make me look like a right tit, but in the interest of honesty and all that haha! Just tried pressure testing the system again, this time in my garage, and also with the right pressure, where I wasn't putting enough pressure through it before, 10 seconds later and I can hear the sound of "drip drip drip", look under car and there is coolant coming out! It's coming from somewhere behind the engine, but it's too hot to be messing about under cars tonight so gunna jack it up and take a look tomorrow! Any common problems from back there with coolant?
 
We it's good news that it is outside the engine not in it. What pressure did you end up using in the end it would have been evaporated with the manifold heat/ hot surface which had to be why you could not spot it pooling. Might be a corroded frost plug or the pipes to the cabin heater.
 
Hello buddy :smile:, I shall have a gander at that tonight thank you, hopefully nothing too serious, only thing I'm concerned about is its quite snug up there and I don't have the smallest forearms in the world haha, but where there is a will and all that!

Pressure wise, I was never sure how much to actually stick through it and I didn't wanna over do it and end up bursting a seal somewhere, but I put out a post on Facebook on the clio forums and a lad came back with 3 figures he got from his workshop guide for me and we deduced that 1.4 bar was adequate enough, which is what I used and found the leak
 
Depending on which heater matrix hose it is, if it's the one on the bulkhead (with the bleed valve), the bleed valve on mine broke (as someone before had tighted it sooo much) I took it out to drill the plastic bleed screw out, it wasn't that hard to remove, so if it's that to replace it's just routing and spring clamps that need undoing (if you have the proper spring clamp tool it's easier than when I was using pliers / mole grips).
 
So! Got home today, had another go at finding the leak, jacked up car, axle stands of course, pressurised the system and got under the car, couldn't see anything from underneath, got a coolant facial for my troubles , looked up top again and I could just see a slow leak coming, it was coming from the right pipe from the matrix, the spongey bit was all sodden in coolant, im not sure if I've fixed it or not, as I need to wait for some more coolant to come in the post tomorrow, but it looks like that jubilee clip wasn't doing its job properly! I've put a new one on and filled it with what coolant I had and can't replicate the leak, but that's not to say there just isn't enough coolant in there to do it again anyways! Very much hoping it's not the heater matrix but ya never know! Again thanks for the help though guys, I really appreciate it, nice to still see people are using the forums and not all Facebook
 

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cool! cheers bud, ordered some new ones and a pair of spring clamp pliers also! dont know how ive gone so long without some to be honest XD