Vauxhall Mokka X - Coolant tank not filling

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Mon 25 Sep 2023 19:36
Vauxhall Mokka X - Coolant tank not filling - Abi latham

Hey,

I've got a 1.4 mokka X 2017 petrol

I purchased this 2nd hand in January of this year.

A few months ago (around june) I noticed that the heating wasn't working properly, I read a few Google threads and decided to take it to halfords for a coolant change.

They done this, the heating worked for 1 day then stopped again. So I put it down to a different problem, it's been warm so it wasn't a concern at the time to get it fixed.

Friday I went to put screen wash and noticed my coolant tank was empty, bone dry! I went back to Halfords and purchased a 5l coolant/antifreeze and topped it up. The coolant started to glug glug out the tank and the tank was empty again, I left it and went inside to watch a few YouTube videos and do more research.

From what I could gauge a coolant tank can hold 3-5lts so I topped it up the next morning, this time the coolant stayed in the tank, success!

I done alot of driving over the weekend and for some reason checked it again on the Sunday, the coolant tank was empty only this time there was a small amount left in the bottom. This made me think there wasn't a leak but there could be another issue?!

I only put around 3lts of coolant in the tank, I am scared to put more in incase I flood something and cause a bigger issue.

Does anyone one what could be the issue before I take it to a mechanic?!

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Mon 25 Sep 2023 20:30
Vauxhall Mokka X - Coolant tank not filling - elekie&a/c doctor
If you are losing that amount of coolant, there’s a big leak. Get a garage to pressure test the system.
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Tue 26 Sep 2023 10:26
Vauxhall Mokka X - Coolant tank not filling - daveyjp

Friend had same issue with a 66 reg. Overheated on motorway, called me, my first port of call was waterpump as header tank empty.

AA came out, diagnosed faulty pressure cap (never looked at water pump for evidence of leaks) and fitted a new one, all seemed OK.

Two weeks later same issue, water pump failure. Now fixed.

Edited by daveyjp on 26/09/2023 at 10:27

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Wed 27 Sep 2023 10:56
Vauxhall Mokka X - Coolant tank not filling - madf

Look for water stains round the radiator cap and water pump Colour same as anti freeze

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Wed 27 Sep 2023 11:01
Vauxhall Mokka X - Coolant tank not filling - madf

Look for water stains round the radiator cap and water pump Colour same as anti freeze

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Wed 27 Sep 2023 11:46
Vauxhall Mokka X - Coolant tank not filling - Bromptonaut

Is there evidence of coolant 'blow off' anywhere, for example around the pressure cap.

Any dripping under the car or suggestion of liquids accumulating in the under tray.

Is the exhaust unusually steamy or can you small coolant around the tail pipe when the engine is running?

Last time I saw anything like you describe was a Peugeot 104 in the early eighties! Internal leak via a failed cylinder head gasket. It was also prone to leaks around the cylinder liners but I'm not sure fabricated blocks and liners are current these days.

Is there any evidence of leakage into the car around the heater or its plumbing? The 104 mentioned above did this one too; filled the passenger footwell!!

It needs a proper pressure test and technical looking over. Problem won't go away and running coolant low is asking for overheat damage.

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