Mysterious Coolant loss

[Insanity-74]

My Fabia vRS has been suffering from some coolant loss, at first I feared the worse....head gasket, but there are no signs of HG failure...there is no mayo in the cap, no signs of coolant in the oil, and no signs of oil in the coolant.

I cant find a leak anywhere, the carpets are dry, read up on here about comon places that seem to leak coolant....no signs anywhere. No signs of the readitor leaking....replaced the expansion tank cap just in case....but no change...still loosing coolant.

The amount is relitavely small.....from the max level in the cooling tank to the min level over 200 miles.

What to try next? I`m told the engines are tough and HG failure is rare...is this true.

Could it be an airlock?

what else can I check.......I`m all out of ideas.

cheers

Nial

[swedishskoda]

oil/coolant mix does not necessarily occur, it depends on where your gasket is damaged (if it is). Could be that the (faulty) head gasket allows coolant into the cylinder (but not into lubrication channels). In that case it might be worth to check for exhausts in the coolant - that's how my garage diagnosticised a blown HG on my Felly.

And even if blown HGs are rare they occur...

SWMBO's Octy suffered from a 'hidden' leak couple of years ago: it was a narrow return pipe to the expansion bottle that was cracked and it wasn't possible to see that it leaked. Loss was much less than max > min in 200 miles, though.

[Insanity-74]

The only thing I think is a bit strange is that even when cold, the cooling system is pressurised, is this because its a sealed system? or does this indicate a fault somewhere.

[Tech1e]

Probably going to be a head gasket, seem to be getting a few as the 130PD gets older but get it diagnosed first, a block check will test cooling system for combustion gasses and a cylinder leakage test will test the cylinders for pressure loss.

[Insanity-74]

Well its into the garage for a check now....will see what the result is shortly...fingers crossed.

[fabdavrav]

Had the similar problem...turned out it was the thermostat switch? halfway down the rad on the passenger side..the washer/o-ring seal had gone!

[Insanity-74]

Had the similar problem...turned out it was the thermostat switch? halfway down the rad on the passenger side..the washer/o-ring seal had gone!

Cheers I will give that a try.

I got the results back from the garage...block check revealed nothing, particulates check came up clean, they pressurised the system to 1 bar above normal operating pressure...no leaks.

The only suggestion was a water pump fault???? but its still a mystery as to where the water is going???????

[ste372]

water will probably be leaking out of the overflow on expansion tank. do you drive it hard? i only ask as mine is doing this at the moment when its driven hard. ive narrowed it down to the water pump.

sniff test was ok on mine and compression test came back at 260 across all four chambers

[Insanity-74]

I dont drive it hard hard...but it does get a little thrashing here and there...the odd squirt here and there on the motorway but nothing too severe.

[Sy.]

I had a crack in my heater matrix pipe where the 2 pipes are joined with a plate. A tiny crack on the weld.

Look down the back of the engine

[Insanity-74]

OK...a slight update. I have found out where the coolant is going....its not going anywhere.....the cooling system is getting pressurised so pushing the coolant into the system somewhere......If I slowly unscrew the header tank filler cap, there is a hiss of escaping air and the fluid level returns to where it was....it does this even when the engine is cold.

The only conclusion I can come to is the dreaded head gasket, so i will be calling the garage i bought it from and getting them to sort it out.

are there any issues with replacing a head gasket? are there any upgraded ones available or is it best to stick with OEM?

I`ll get the cam belt, associated parts and water pump changed.....is there anything else I should do at the same time??

Not a good start to Fabia ownership, if the car wasnt in such good condition I`d get rid and start again.

[ste372]

if it doesnt pressurize under normal driving conditions then its mostly likely to be waterpump like on mine. what mileage has it done and has it had a water pump in the past?

mine only loses water when driven over constant 3.5k rpm on a journey, the water pump plastic impellors are failing and need replacing im limping mine around at the mo till we get a spare couple of hours in work hopefully this week sometime

best advice i can give to you is to take it on a drive on motorway (if possible) stay at constant speed e.g. 60mph = 1800 rpm check after few miles see if expansion overflow is leaking it will be wet near fuel filter. then do the same drive back at higher revs 3-3.5k check after couple of miles see if coolant has come out of overflow pipe and has leaked. that is how i suspected my waterpump.

[Insanity-74]

I cant tell from the service history if the water pump has been changed or not? I "think" the water pump is working as with the cap off the expansion tank I can see water flowing from the top most hose into the tank. Its problem is pressurising too much....the pressure is remaining in the system even overnight.

[ste372]

hopefully ill be doing mine tuesday so will report back if waterpump doesnt cure mine ill be whiping the head off aswell lol

[Insanity-74]

hopefully ill be doing mine tuesday so will report back if waterpump doesnt cure mine ill be whiping the head off aswell lol

Hahaha you make it sound so easy.....thanks for the help so far, much appreciated.

[ste372]

believe me easy is the last thing it is lol.

[Rex VRS]

Hi there, I'm new to Brikskoda and only had my VRS a few weeks.

I had the same issue, coolant loss and pressure in expansion tank. It turned out to be head gasket and the dealer took it back and fixed it luckily.

I had pressure in the expansion tank even when left over night. I think this is exhaust gases getting in to the expansion tank and forcing the coolant out.

I took it to a Skoda dealer and they did all there tests and they said it was fine and unlikely to be the HG. Unluckily for me they were wrong but I cannot fault the dealer enough for sorting it out as I was gutted.

Good luck with it

[Insanity-74]

Well its gone back to the garage that I purchased the car from and they are going to fix it for me...the aftersales has been spot on from what is a small second hand car dealer, cant fault them at all. I hope they manage to get it sorted out....if not there was a nice Fiat Punto Abarth in which would make a vary nice replacement.

its odd as only the top of the radiator is getting hot, the bottom remains stone cold, but the car isnt overheating at all...god knows what it is...most people seem to be at a loss.....my gut feeling is head gasket...will see.

[kerms34]

Ive got the exact same problem ,,, coolant going missing over a week or so, not much though.

Took expansion cap off today and heard the hissssss and level returned to normal ,,, have read a lot of threads on here this afternoon and most end up saying that its the head gasket.

Now my Vrs is an 05 with 60k , could it really have gone that early ?

Before I replace the Cap and then the tank ,, has anyone actually solved the problem by doing this ?

[tarnie2011]

this seems to be a common issue as my w plate 1.4mpi started with a mystery leak, thought i'd sorted it, when i checked to see if the thermosat had gone, when the housing was sepaetated to then test thermostat i noticed that the plastic around where the screws went into was distorted around the holes,replaced the housing this resoleved the issue for about a week,

now i have another mysterious leak to find

[viewer]

Also check rubber sealing ring on temperature sender at back of block.

However, If it isn't losing water but level in tank is dropping then returning once pressure is removed it suggests an air lock. The air would compress and stay compressed until you removed the cap. There is a sequence of actions for systematically bleeding the cooling system as it doesn't always self clear air. For worries about head gasket - has the coolant colour changed?

[Insanity-74]

Well, it turns out it was a blocked radiator...or so the garage says...will find out if its fixed tomorrow

[kerms34]

how did it go mate ???

[Insanity-74]

Well.......its getting strange. :wonder:

After having the radiator flushed and the header tank replaced its been fine for a week.....then today the low fluid level light/alarm went off.....(oh bugger) so I stopped and topped it up with the 5litre tank of water that now lives in the boot.....carried on driving as normal.

When I got home the level in the header tank had gone back to normal plus the extra I had topped up the tank with so the water obviously isnt going anywhere outside the cooling system.....I dont know where its hiding though....daft car.

[ste372]

my water loss turned out to be waterpump. the plastic impellor was swelling when the car was driven hard. changed timing belt and waterpump and has been fine since

did you check wheather it was wet around the header tank, near the fuel filter housing. the raised level in header tank sounds like what mine was doing. the level on mine would rise and leak out through the overflow spout