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Mystery coolant loss


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I've noticed over the past few months that I need to top up the coolant on my Felicia more often than  did. There are no obvious leaks, no mayonaisse under the oil cap, no steam from the exhaust. Temp. gauge works as it should, ie; not going above it's normal mark, but it does seem to take longer to heat up the cabin though. The speed at which the blowers got nice and hot has always been a good point until now.

 

I haven't checked the coolant for a few weeks, but after the snowy weather here, I thought I'd better start her up and see if all is well after being sat in the snow for 4 days. The coolant reservoir was empty! It took 1.8 litres to get it back to betweeen the min and max marks.

 

There is  no clear cause as to where it's going, any suggestion?

 

 

Edited by myjalopy
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56 minutes ago, myjalopy said:

I haven't checked the coolant for a few weeks, but after the snowy weather here, I thought I'd better start her up and see if all is well after being sat in the snow for 4 days. The coolant reservoir was empty! It took 1.8 litres to get it back to betweeen the min and max marks.

To me that is a clear indication of an external leak. You need to check for leaks more thorough. Places to look: the coolant pump hole, the intake manifold gasket, the thermostat gasket, the matrix heater. The best would be to do a pressure test by pressurizing the circuit to 1.1 atm with compressed air and look for leaks.

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Hi Ricardo

I will do a more thorough check, but so far there is no obvious leak. Ive checked the places you mention briefly earlier today and I'd expect to see pink powder or pink fluid there, but nothing.

I'll check it again after a run tomorrow.

 

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This is one way of testing the cooling circuit. You can have a tyre valve on the T for easy fitting a manual/foot pump or a small compressor. It is recommended to have a pressure gauge to the air source.

kH9KXby.jpg

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Checked it tonight after it had been sat for 12+ hours. No loss apparent yet, but too dark to make any leak observations other than already done. Another thread mentions looking for pressure in the expansion tank in the morning after use, but none observed this morning or this evening after 12 hrs at work.

 

I'll monitor it over the next few days and then do a proper check in the daylight.

 

 

 

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On 3/3/2018 at 13:25, myjalopy said:

... no mayonaisse under the oil cap, no steam from the exhaust.

Those are extreme signs when the fault is major. There are intermediate phases between no leaks and a badly failed head gasket (HG). For instance, a tiny crack in the HG between coolant and combustion chamber may result in dropping the coolant level under MIN in 3-4 weeks with no obvious signs. I've inserted below a descriptive photo of all HG possible failures.

eaWtpfr.jpg

Coolant leaks should be investigated thoroughly because ignoring them could lead to expensive repairs. Engine overheat may be partially masked by very cold weather.

 

In conclusion, do your best to find external leaks in places hard to reach (back of the engine, matrix heater, pump weep hole, etc.) It is a difficult job, especially if the leak occurs only when the engine is hot and the coolant tends to evaporate.

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  • 3 weeks later...

Had to top up again yesterday, so had another look around and there is a pink stain on the edge of the radiator coming from the top. hadn't noticed it before. It isn't wet or damp, just dry powder but clearly shouldn't be there.

 

I'll try to put some pressure into the system as per your suggestion RM, see if it forces anything out of the stained area on the radiator.

 

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@myjalopy - Well, to me your last is strongly suggestive of a weep from the radiator header to core joint. Is this a "modern" composite plastic and aluminium radiator? (because they're more vulnerable to that failure than "olde-fashioned" all metal ones.)

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Hi Ken, it's the original all metal one it seems. I must say that replacing the rad. is a better option than some of the other possible leak areas. Weird why it's not damp though.

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  • 3 weeks later...

Hi. still replacing coolant on a weekly basis ( 80 miles ) so I decided to get some pressure in the expansion tank by using an old cap that fitted, made a small hole and attaching a tyre inflator to it with some araldite around the valve/hole. Crude but effective. I didn't notice anything unusual except the bottom pipe coming from the expansion tank showed some weeping. Upon inspection, I noticed that it may have been doing it for some time as there was dampness running along the 'ledge' below it. Since then I have noticed that this pipe weeps more often than not. I have also noticed that there is a slight whoosh of air when I remove the cap even when the engine is cold.

 

Over the last couple of weeks the engine is lumpy, like it's only on three cylinders, when started in the morning or after work. It soon goes away after a minute.

 

 

 

 

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I would do a cylinders compression test then in case some cylinder(s) leak(s) I would do a cylinder pressure leak down test.

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@KenONeill If you refer to those gizmos that look for liquid colour change from blue to yellow/green, they are rubbish. Good in theory, inconclusive at best in practice.

There are better and definitive ways to do that. See one below for very small head gasket leaks to cooling system.

 

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Went to the garage today and they put the 'sniffer' to work ( as suggested by RicardoM, cheers.). The readings started out at 2100+ on the hydrocarbons, but when he pulled the  nozzle out onto the edge of the expansion tank filler hole, they hovered around 700. The engine wasn't as hot as it could be, but he said that anything over 100 is fairly clear it's a HG issue.

 

They suggested using 'steel seal' as a temporary fix but really the HG needs to be done.

 

I reckon I could have a go at doing it...:sweat:

 

 

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I understand that you don't feel confident to do a honest head gasket job. Yet there are many topics (a couple of them in detail with photos) that describe how the job has been done successfully in the backyard by DIY-ers. Some didn't have the luxury to work during spring or summer, they had to work in cold and wet conditions, yet they did the job well.

 

So, I know what you're thinking. You're weighing the 'hassle' and expenses of doing the right job against the commodity of pouring a liquid into a hole. The latter is called 'an additive'. It is, sadly, a multi-billion dollars industry based on the ignorance, commodity, and gullibility of people. The additive manufacturers (poured in fuel, oil or coolant) claim the heaven on earth yet they feel the need to write in very small letters that they are not responsible if the product did any harm or it didn't perform 'up to' the marketing BS they advertise. They know very well the psychology of potential buyers, they know exactly how much money to ask for their product, usually a lot but not too much to discourage people, just enough to fool them.

 

Now, from the technical perspective, we are dealing with a head gasket that is on the verge to lose tightness totally, usually in a catastrophic way. It is about either a corroded cylinder head or a head gasket falling to pieces or both. It is metallic material that is not there to seal anymore. Yet the magic liquid can fill somehow those holes and resist to repeated explosions of high pressure and high temperature...

 

I will post two photos below that show how a corroded cylinder head and a failed head gasket look like. This is how they were found after opening the top engine. I will let you decide if the magic liquid can repair the damage. Even if by chance the tragic end is delayed, you'll pay for the additive, you'll get a cooling system full of it (often with adverse effects), and you'll still have to do the proper job. It's your call. Your money.

 

0tIhJ43.jpg

 

3AtLDZx.jpg

Edited by RicardoM
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4 hours ago, myjalopy said:

Why not? I was sceptical but have read so many positive reviews compared to negative ones.

 

From bitter experience - these sort of things are good at sealing things you don't want them to seal. I had a weeping radiator on an Allegro a few years ago and put a sealer into the system. This worked for a brief while but eventually failed again. Radiator still had to be replaced and the heater matrix ended up being sealed up and never worked again. Wished I'd done it properly in the first place!

 

Sound like you have a head gasket and radiator issue. Fix them both whilst you are at it and put a good quality anitfreeze in afterwards - easy and cheap jobs - for now!

 

I've just changed the rad on my old Octavia as I saw a slight drip on the ground, although it did look dry from the heat! You could see the pink/purple stains though. Except for a couple of difficult bolts that hadn't been disturbed for 17 years - wasn't too bad a job, although I spent a lot of time rustproofing whilst car was raised up, it's 2001 body is rust free but the rad surround and engine/suspension subframe did had some signs of rust - held at bay with a messy mix of oil and waxoyl (same method I've used in car restorations over the years). 

 

 

 

It's just been driven Yorkshire to Portsmouth and back by my son - no further issues :)

 

 

 

 

Edited by bigjohn
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Hi chaps. I know what I should do, but I have been weighing up the benefits of doing it. My old Felicia has done me proud, but at the last MOT there were several issues that were unlikely to pass next time - most of the brake lines and a steering joint are two that I remember. Replacing brake lines isn't a job I'm happy to mess with, although I have in the past. That means the expense of paying a garage to do it.

 

The costs start to add up. Now a HG and radiator, cheapish but an additional cost. Over the next year, I could be looking at hundreds of pounds just to keep it going. The bodywork is not too good, but mostly cosmetic at the moment, although the rear wings have gone through around the arches.

 

I am more than happy to replace the HG myself. I've read some of the stories here and elsewhere and It doesn't seem as complicated as it sounds. The outlay is reasonable, less than £100 for the HG, bolts, coolant and a new radiator and doesn't involve scrabbling around under the car - much.

 

Maybe I will give it a go......:biggrin:

 

 

 

Edited by myjalopy
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OK, first hurdle. I was just looking at potential issues with this and see that the exhaust manifold bolts are seized. The only bolts that are accesible it seems, are at the metal gauze gasket end, even then they seem quite solid too.

I'm considering cutting the downpipe and doing it without taking the manifold off. Then put a joiner that I've seen online on the pipe afterwards. Daft idea or workable?

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Use the big red wrench aka an acetylene blow torch plus wax. Maybe a regular blow torch could do the trick too.

 

Some food for thought.

 

 

 

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