Clio - just where is the coolant going?

Renault Clio is losing coolant and needs topping up with water / antifreeze about every 200 - 300 miles? Use a 1:4 mix. About 1/2 pint at a time up to the min. mark on the expansion tank- obviously a bit more when filling up to the max. Not a lot of driving in standing traffic - a fair amount of long distance stuff including motorways. Went to Edinburgh / Glasgow the other day and needed about 11/2 pints overall. Looked all over and under the car and the heater matrix but can't find any trace of a leak. Anyone had a similar problem? Can't understand how it can be losing it - can't imagine it's being boiled away. A mate said it could be going and getting lost in the air-con system but I can't imagine that. A bit loathe to use any Radweld but I will as a last resort. Any ideas out there? Thanks:help:

It has to be leaking from somewhere - perhaps it only leaks when it is under pressure so you don't notice when it isn't running.

Get some Radweld in and worry about it in the New Year

Leaks can be hard to find. On a dry day top the coolant up and go for a decent drive (at least 20 mins) to get the car up to temperature. Come home, park up and leave the engine running for another 5-10 mins. Now look under the car for puddles. (If you have an undertray below your engine, remove that before any of the above).

If there isn't a leak, I'm sorry to say there is only one other possibility; head gasket troubles. Open your oil filler cap and look for excessive amounts of white gunky stuff. After your run out in the car, and with the engine still running, go and see if an excessive amount of steam is coming from the exhaust (easier to diagnose on a warm day if possible).

Also check for blobs of oil in the coolant expansion tank, and blue smoke (that smells of burning oil) coming from the exhuast (easier to spot in bright, direct sunlight).

Good luck!

Yup....my money's on the head gasket failing too.

Possibly inlet manifold to start with, but....no....I'm going to stick with the dreaded HGF - sorry!

I agree, Head gasket, my son has just had the same problem, cost him £300 to get the head skimmed new gasket and put back together.

£300 lol get a new clio for that

Expansion tanks on clio's are fairly weak and will split along the moulding lines.

Also check the tank cap for leaking water/steam.

if you talk nicely to your local garage they will put their exhaust gas probe above but not in the coolant tank which will sniff any combustion gas if its present. If it's present that usually points to head gasket but not always.

could be the rad bulging under pressure?

It wont be in the aircon as that's a different system. Have a look around the water pump etc for any green crystallization as that may help indicate where the leak is.

oh no wait... its the head gasket..... it always is!

could be the rad bulging under pressure?

It wont be in the aircon as that's a different system. Have a look around the water pump etc for any green crystallization as that may help indicate where the leak is.

 

 

 

 

 

 

 

 

oh no wait... its the head gasket..... it always is!

Nice flippant remark there. Would you care to tell me, exactly how does a solid metal radiator buldge?! As it's a sealed system, even if what you are suggesting were possible, the temporary increase in the system capacity would be reversed when the coolant returned to ambient pressure. As this system is repoertedly consuming coolant, and it's apparently not leaking from anywhere, there are only a limited number of places it can be going. A tardis-like radiator isn't one of them.

ahh steve... hows the single?

as for the rad. If the rad has been damaged..or had some form of impact it can damage the ends or bottom. Due to how a rad is made it only becomes apparent when the system is under pressure and causes a leak.... it doesnt bulge like a tyre would or something like that.

I have only ever known it to be called a rad bulge. It may have another name that others know it by but that's what I was taught.

edit: hmmm thats a really bad description but I hope you get the gist..

also the expansion bottles can do the same. mine did it on my old bmw. it only leaked when the system was under pressure.

just throwing in a possibility of what to look for.

I also dont see where the OP states its consuming coolant as opposed to it leaking. Just because they haven't found anything obvious doesn't mean it isn't as I found out when I had a problem on my supra. It turned out I had a split pipe on one of the heater matrix hoses. this was dropping down onto the block and evaporating. Took me ages to find as only spotted by chance when I couldn't find the reason for the loss of my coolant. first thing people said to me was its definitely the head gasket.... so its also one of my pet hates.