Hello

I've got a coolant leak. It's not a fast leak, so I only need to check it every 2 or 3 weeks, but obviously it'd be better if it didn't leak at all.

Now I could replace the reservoir (they seem to only cost about £12!), but it's occurred to me that it might be one of the hoses/connectors that's leaking.

So, is there a magic way I can find out exactly where the problem lies? I could take it to a garage, of course, but I recall I was quoted about £180 or whatever and that sounds a bit extreme when the reservoir itself only costs just over a tenner. They did explicitly state that it was the reservoir that was leaking though (this was spotted during an MOT test).

The car is a 2001 Zetec.

they crack underneath out of sight

 

if you can see a lot of antifreeze stains / traces of water on inner wing / engine mount, get the engine hot till the bottle is nice and warm (it help makes the plastic flexible) then grab hold and lift upward....  once clear of the three mounting "tags" turn it over and look (don't loosen the cap or disconnect pipes)

If you can’t find it then consider this,

engine repair or replacement from overheat > £180 fault finding and fixing before problems happen. 

It may be a slow leak now but if it gets worse it will cause problems. 

Do you have any crystallisation anywhere? My old focus had a small leak that had coolant crystals where it was leaking. 

I had a coolant leak which turned out to be a cracked thermostat housing. It was more of a leak than yours though, so just a suggestion for you.

On 8/3/2018 at 4:39 PM, jpjeffery said:

So, is there a magic way I can find out exactly where the problem lies?

I put some cardboard under the reservoir. After a day or so, it got quite soggy. I eliminated the vent hole from the filler cap by taping over it. Tape stayed intact, no water in vent hole, cardboard still soggy.

I replaced the reservoir (£21, and very hard to find a new one back then!), problem fixed. I have never managed to locate the crack in the old reservoir. Nothing visible at all.

Leaky reservoirs seem to be a very common fault.

On 8/3/2018 at 7:18 PM, Botus said:

they crack underneath out of sight

 

if you can see a lot of antifreeze stains / traces of water on inner wing / engine mount, get the engine hot till the bottle is nice and warm (it help makes the plastic flexible) then grab hold and lift upward....  once clear of the three mounting "tags" turn it over and look (don't loosen the cap or disconnect pipes)

 

19 hours ago, Pebbleheed said:

If you can’t find it then consider this,

engine repair or replacement from overheat > £180 fault finding and fixing before problems happen. 

It may be a slow leak now but if it gets worse it will cause problems. 

Do you have any crystallisation anywhere? My old focus had a small leak that had coolant crystals where it was leaking. 

 

16 hours ago, Stevesixty7 said:

I had a coolant leak which turned out to be a cracked thermostat housing. It was more of a leak than yours though, so just a suggestion for you.

 

9 hours ago, Tdci-Peter said:

I put some cardboard under the reservoir. After a day or so, it got quite soggy. I eliminated the vent hole from the filler cap by taping over it. Tape stayed intact, no water in vent hole, cardboard still soggy.

I replaced the reservoir (£21, and very hard to find a new one back then!), problem fixed. I have never managed to locate the crack in the old reservoir. Nothing visible at all.

Leaky reservoirs seem to be a very common fault.

Thanks for the replies, everyone. Very kind.

I had a slight coolant leak on a fiesta 1.6tdci. could not find the leak so put radweld in it. was OK for a while but then leaked again. But the radweld helped me find the leak due to the red radweld stain it left where the leak was. It was the plastic thermostat cover leaking slightly. So whilst radweld might be considered a bit of a bodge it did help me find the leak

4 hours ago, isetta said:

I had a slight coolant leak on a fiesta 1.6tdci. could not find the leak so put radweld in it. was OK for a while but then leaked again. But the radweld helped me find the leak due to the red radweld stain it left where the leak was. It was the plastic thermostat cover leaking slightly. So whilst radweld might be considered a bit of a bodge it did help me find the leak

Until your reply today I'd never heard of Radweld. Sounds kind of neat though, but then Radweld at £7.99 or a new reservoir at £11.00...?

Having watched a couple of videos on the replacement procedure, I see there are only the three hoses which are visible at the front (2 smaller ones at the top, plus the larger one at the bottom).

So at most I reckon I just need to check the state of the larger hose where it connects to the reservoir. I had been assuming that there was something going on underneath the reservoir, but it looks like that's wrong.

"Until your reply today I'd never heard of Radweld. Sounds kind of neat though, but then Radweld at £7.99 or a new reservoir at £11.00...? "

yes, as I said Radweld is considered a bit of a bodge, but can be useful if desperate  eg. if I found I had a slight leak and was going on a 1000 mile road trip starting this evening, then Radweld is better than doing nothing (where there is lack of time or parts to do anything else).

I would guess that maybe AA/RAC etc carry it as a get you home measure.   Any breakdown assistance staff reading this ?

Many repair products are not as good as they claim to be and don't perform the miracles you would expect from reading the blurb

Radweld is best used on an old engine you don't care about...  It can block waterways and small pipes causing even bigger issues.  I pulled the head off a car with a blown HG a couple of years ago, the owner had used radweld (probably more than they should!) and there literally strings of it going right down into the block like manky spaghetti!

It can work as a quick fix if you're desperate, but I wouldn't risk it on a car I wanted to keep lol.