Very slow coolant loss

[Pricey98]

I've noticed that the coolant level on my 172 has dropped very slightly over the last few weeks. It was on the maximum line when cold, and now its maybe half a centimetre or so under (checked on level ground). There's no cross contamination between coolant and oil that I can see by checking visually (oil is clean as is coolant). I have however noticed quite a few small white powdery specs around the engine bay. I remember cleaning quite a few off when I first got the car, but there's still quite a few there. I'm thinking that I probably have a very small leak somewhere, or maybe my coolant expansion tank cap could be a bit past it. Head gasket has crossed my mind, however I'm lead to believe that HGF is very rare on F4R engines. Thoughts?

 

[DrR]

Have you topped it up more than once or is the first time you noticed it?

I’m pretty sure my 172/182 had various level of coolant, as long as it’s staying between max and min I wouldn’t worry about it.

 

[Pricey98]

Have you topped it up more than once or is the first time you noticed it?

I’m pretty sure my 172/182 had various level of coolant, as long as it’s staying between max and min I wouldn’t worry about it.

I haven't actually topped it up, as is only marginally below the max line. Engine temperature sits happily at halfway too. The only sign I can see of any potential leak is those white specs, which could be dried coolant. Does seem plausible that the level could vary slightly due to outside temperature, etc.

 

[White16valver]

Until/unless you're topping up regularly, I'd just keep an eye on it and wouldn't worry too much lol

You could go round all the connections with some tissue paper when it's both cold and hot, to see if there are any leaks, and you could check round the radiator cap and all the rad joins/welds too, as sometimes they weep under pressure and due to old age AIUI.

I had mysterious coolant loss too in my current car - new rad and cap and it's been spot on since.

 

[imprezaworks]

Be fine.

 

[Pricey98]

Be fine.

Think I'm probably just suffering from 'old renault paranoia' lol.

 

[Pricey98]

Quick question. The coolant that's in there is long life red (unsure of brand). I've bought some long life red pre mixed for top ups if needed, however it's more pink than red in colour. Are pink and red coolant OK to mix?

 

[White16valver]

There are various different types of coolant - glycol-based (without silicate or Organic Acid Technology) that can be in older/classic cars, non-OAT with silicate (that can be in slightly newer cars), OAT without silicate (in newer cars), Hybrid OAT with silicate...

https://www.halfords.com/advice/motoring/expert-advice/which-antifreeze-should-you-use-for-your-car

https://en.wikipedia.org/wiki/Antifreeze

You should read your handbook to check - it might even be worth going to Renault and asking them for the price of antifreeze for your exact vehicle.

Many people just stick whatever they have locally in, and seem to do just fine with it, but using OAT long-term in an older car might eat any yellow metals in the system, AIUI.

 

[Pricey98]

There are various different types of coolant - glycol-based (without silicate or Organic Acid Technology) that can be in older/classic cars, non-OAT with silicate (that can be in slightly newer cars), OAT without silicate (in newer cars)...

https://www.halfords.com/advice/motoring/expert-advice/which-antifreeze-should-you-use-for-your-car

https://en.wikipedia.org/wiki/Antifreeze

You should read your handbook to check - it might even be worth going to Renault and asking them for the price of antifreeze for your exact vehicle.

Many people just stick whatever they have locally in, and seem to do just fine with it, but using OAT long-term in an older car might eat any yellow metals in the system, AIUI.

Ideally I'd use Renault type D, which is green, however the garage that did the coolant change used the long life red/pink stuff. Once I've freshened up my engine bay over the winter I'll be getting a new coolant expansion bottle, so will go with the recommended type D stuff then.

 

[White16valver]

Ideally I'd use Renault type D, which is green, however the garage that did the coolant change used the long life red/pink stuff. Once I've freshened up my engine bay over the winter I'll be getting a new coolant expansion bottle, so will go with the recommended type D stuff then.

Should hopefully be fine for a few months till you change it!

 

[Pricey98]

Should hopefully be fine for a few months till you change it!

Yeah, should be good. I'm sure I read somewhere that some people actually prefer the red/pink stuff over type D as it has better anti corrosive properties for aluminium.

Got quite a few plans for the car over the winter, complete engine bay freshen up being high on the list. Thankfully I'm moving house in a few weeks and new house has a garage, so I won't be reliant on the weather for a change ?

 

[Landyman]

This happened to me and it was the water pump weeping slightly. I found coolant under that area and on the engine undertray.
Radiator sealant stopped the leak until l got the cam belt and water pump replaced a few weeks later.

 

[Pricey98]

This happened to me and it was the water pump weeping slightly. I found coolant under that area and on the engine undertray.
Radiator sealant stopped the leak until l got the cam belt and water pump replaced a few weeks later.

Hoping it's not that as had cambelt and water pump replaced a few months ago. I didnt have the thermostat changed though, so that's another possibility.

Will give the whole engine area including hoses, etc a good eyeballing when I get chance, but so far other than the mystery white specs in the engine bay which may possibly be dried coolant, there's no other signs of a leak.

 

[Landyman]

Well as you say, it’s unlikely to be the water pump on yours.
Do you have coolant dripping underneath at all?

 

[Pricey98]

Well as you say, it’s unlikely to be the water pump on yours.
Do you have coolant dripping underneath at all?

Nope, nothing underneath.
Probably makes sense to replace the expansion tank cap for the sake of a tenner or so and see if that makes any difference. Cheap things first lol.

 

[imprezaworks]

Slim but could be the head

 

[Pricey98]

Slim but could be the head

Always a possibility I guess, although pretty rare as you say.

 

[SophOwen]

I've noticed that the coolant level on my 172 has dropped very slightly over the last few weeks. It was on the maximum line when cold, and now its maybe half a centimetre or so under (checked on level ground). There's no cross contamination between coolant and oil that I can see by checking visually (oil is clean as is coolant). I have however noticed quite a few small white powdery specs around the engine bay. I remember cleaning quite a few off when I first got the car, but there's still quite a few there. I'm thinking that I probably have a very small leak somewhere, or maybe my coolant expansion tank cap could be a bit past it. Head gasket has crossed my mind, however I'm lead to believe that HGF is very rare on F4R engines. Thoughts?

I know an issue I had when I first brought mine was the same. It's not a 172 so can be sure but my expansion tank had a tiny crack underneath. Similar sort of thing.

 

[Pricey98]

I know an issue I had when I first brought mine was the same. It's not a 172 so can be sure but my expansion tank had a tiny crack underneath. Similar sort of thing.

I'm thinking along similar lines tbh. Quite possibly a very small crack or split in a hose somewhere that's only leaking very slightly when under pressure. Would also explain the little white specs in my engine bay that look like dry coolant, although can't pinpoint exactly where they're coming from.