Weird coolant loss on long journeys - water pump?

[eye_flys]

My Octavia has been losing progressively more coolant. I've kept it topped up and it hasn't overheated yet.

It only happens on long journeys, approximately 1-2 litres every 100 miles, leaving the engine idling for an hour doesn't result in any coolant loss.

There is no coolant/engine oil contamination or vice versa (phew!)

I've taken the timing covers off today, and though the crank pulley was a bit wet, the water pump seems dry. There is a bit of a worn bearing noise with the engine running.

There was an obvious coolant smell when I opened up the wing liner.

Reckon I'm on the right path with the water pump? I've not known one to leak intermittently.

[trundlenut]

Head gasket going but only leaking under sustained load?

Could pressurising the coolant and forcing it out the overflow into the wing.

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[rwbaldwin]

To check the water pump, remove the reservoir cap, raise the engine rpm to about 2500 and check there is a steady stream of coolant from the return pipe.

I agree with trundlenut, if you are getting coolant in the wing it is likely due to exhaust gas forcing the coolant through the cap. Get a block test done.

[eye_flys]

Balls.

Seems increasingly likely now, the water pump is fine...

Edited 24 June, 2013 by eye_flys

[sparks03]

Check all hoses too. If one has started to perish/ the circlip failed and is not sealing properly it could be forcing out water.

[eye_flys]

 

I hope it's not a hose, because I ended up doing this.

 

No obvious signs of damage on the head or head gasket, the head's away getting tested just now.

[mbames]

Not a split in the expansion tank is it?  Other members on here have had that problem - it used to only cause coolant lost on longer trips.

[Raf_]

Mine does it, in my case it's around the temp sensor, any reddish stains on top of the gearbox?

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[Bowders1]

Not a split in the expansion tank is it?  Other members on here have had that problem - it used to only cause coolant lost on longer trips.

I have had a split expansion tank that would open the split up over longer journeys

 

Also 2 other places

 

1. The bottom expansion tank hose/metal hose clip can become weak expand and allow coolant loss

2. The temp sensor housing being plastic with a rubber seal , the seal can perish and or the plastic housing can leak.

[Jonny5ive]

Blown radiator. I had the same symptoms with my Fabia, and UNIT18 at first thought HG had gone.

[eye_flys]

Yeah, so there's lots of things it could be apart from the head or head gasket. Bugger!

[Guest BigJase88]

VAG coolant is ultraviolet!

So get a UV lamp and have a look at night!

[sparks03]

Or look for the part of the engine that resembles Millford Sound in the mid 90s :P Its worth checking as i've had this on four of my seven VAG motors so far. Fortunately they've been easy fixes, hope yours is too (should it be that) 

[eye_flys]

UV light is a good call.

Wish I hadn't jumped the gun and taken the head off now, but I can't see any obvious coolant staining apart from the expansion pipe from the header tank.

[andyabb]

Coolant dissapearing skoda Octavia 2.0 tdi used about 2 litres of coolant for 500 miles. Temp fine heater blowing hot and cold. Had pressure test all ok mechanic did say when he started test all water dissapered in expansion tank he topped it up. Could it be a massive airlock? Any advice cheers

[Octabus]

Theres a lot of coolant going somewhere..... I think you would notice a greasy wet film underneath for any major leek (but not with current weather conditions) and you would see a vapour cloud behind from the exhaust (also residue up the back end - again, not so easily spotted in this weather)

 

As you are now plum deep in a doomsday senario..... II would replace head gasket, water pump (get the metal blade type if the diesels have a plastic one) fresh belts, thermostat and see how it goes. a good clean up in the process makes it easier to spot new leeks.

My water pump failed progressively, about a week before hand it emptied the header tank over 25miles.. check all pipes are warm-hot when its up to temperature, this also points to a thermostat problem if there's a chilly pipe when the rest are hot!

[FUBAR]

Mine does it, in my case it's around the temp sensor, any reddish stains on top of the gearbox?

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Mine came off at night under load accelerating just as I hit 60mph..... FIZZLE FIZZLE STEAM BOMB! Car behind me vanished into my cloud..... won't be tailgating any old Skoda's again anytime soon with the mess that will have made of the front of his car Weird thing in my case the plastic retaining clip remained in place and it came out past it and i ring vanished...