Been doing some more research into the Skoda coolant system and found a rare fault that can occur, but thought it was worth mentioning here, for anyone seeing mysterious coolant loss, followed by weird electrical problems. If the system is over filled, coolant can be forced past the seal for the plug that connects to the expansion tank (low level warning circuit). From there, it can be drawn through the wiring loom, into the ECU and or the Instrument panel.

So it would be worth pulling the plug once in a while, and checking for any signs of coolant corroding the plug pins. VW actually issued a technical bulletin for this some time ago. One guy in the states had coolant in the rear light clusters

That's worrying. I'm sure when I last checked my mums coolant level it was well above the max mark. I know you can do some damage if you over-fill the oil, but didn't think it would matter if the coolant was overfilled.

That's worrying. I'm sure when I last checked my mums coolant level it was well above the max mark. I know you can do some damage if you over-fill the oil, but didn't think it would matter if the coolant was overfilled.

Water expands by 4% between 4°C (max density of water) and 100°C, therefore in a sealed system it's got to go somewhere if you have not left room for expansion; find the weakest point or explode .

One other thing to remember in a presurised system the boiling point of water will be greater than 100°C for example of the top of my head at 3 bar it's about 134°C

Regards,

TP

*checks calendar* nope it's not april 1st. Mine seems to simply have the 2 wires visible for a cm or so, so the only way for it to migrate in mine would be via the actual coolant sensor wires which I'd have thought was near-on impossible?!

*checks calendar* nope it's not april 1st. Mine seems to simply have the 2 wires visible for a cm or so, so the only way for it to migrate in mine would be via the actual coolant sensor wires which I'd have thought was near-on impossible?!

The migration only happens if the cable outer sheathing goes right up to the plug. Just checked the VW Technical Bulletin and it seems to only have effected cars between 1997 and 2003. Expansion bottles were made in China If anyone is worried about this, the fix is to remove an inch of cable sheathing behind the plug, and/or drill a 4mm hole through the bottom of the socket aperture that has the sensor pins visible. Be careful not to drill into the expansion tank though. The hole gives the expelled coolant somewhere to go, other than into the wiring loom.

One user in America got a bill for $7000 to repair all the damage done by this fault. New loom, ECU, PAS, ABS. Instrument Panel, Fuse Box. Craziest fault I have ever read about.