Coolant

No, it can "burn" coolant off if there is a way for the coolant to enter the combustion chambers, or it can leak into the oil way - this is most often due to head-gasket failure.

A leak is preferable. I dipped the oil in my old Jaaag a couple of weeks before Christmas to discover it was brown, muddy and overfull by around a gallon. :mad:

corks finest wrote: »

Bad

Very. I scrapped it.

Coolant is a closed loop system, slightly pressurised too.

You can loose coolant if coolant exits this system.

Common faults include.

Pin holes in radiators, old worn hoses / hose connectors, water pump on its last legs, Expansion Tank damaged seals, Expansion Tank Cap not on correctly or needs replacing.

Coolant be utterly easy to locate a leak (if big) or absolutely mind blowingly horrible to locate. Rarely in between

Id check the hoses first and foremost for any breaks or damage and just see if they are old looking (worn). Check the expansion tank for leaks or anything in gaps. There should be a bit if pressure when you open the expansion tank ( not a huge amount but a bit when cold)

There are kits you can get for testing the head gasket isnt leaking into the coolant system, they are 99.7% accurate and can be got for between 15-20 Euro. Simple kit to run just changes colour on detection of combustion gas in the expansion tank.


Hopefully its minor. It can even be something silly like an airlock in a hose and can be squeezed out.- cost. nothing.

ILikeBoats wrote: »

It's a 161 Focus ST diesel.

I noticed it was a bit low on coolant before Christmas, mildly lower again now. Not being lost at a massive rate.

Looking at the hoses, all looks dry and not worn.

I can't even open the expansion tank. It turns a few times then stops.

Any tell tale signs that it's leaking into the engine?

I only bought it in June so full service done then in a main dealer

I would get the system pressure tested asap - as posted above it might be a pin hole leak or poor seal which lets vapor out so your not seeing a leak - fingers crossed

Just to jump on this thread..
If exhaust gases were leaking into coolant and the test proved that was the case (changed from blue to green)and then you think you have fixed the problem,,if you test it again would Co2 exhaust gases still be detected.. do you have to flush the whole system and refil with coolant and then test again!?