Hello,

My first post I think and a slight urgent one as I am working away from home/tools/usual garages etc.

I'm using my girlfriends 2000 1.4 mpi Fabia Classic. She recently purchased it and put it in for a full service (coolant flush etc) at my insistence... now I may be in the dog house!

The car runs fine, no problems - but when left overnight or after a run there is evidence of a small coolant leak (dripping through very front of the undertray, where the very frontal section overlaps the next section back). There is no sign of it when the car is running (30 mins- 45mins). Having nothing to hand tool wise it is proving a bit of a frustration! Nosing around in the engine bay and reaching down to where the leak seems to be originating there is no sign of a leak. Can anyone help/advise?

I have tried searching and one similarity between our situation and others recorded on briskoda is that the coolant gauge has been running exceptionally cold over the past week (barely off the stop at some points - I understand this is to do with the thermostat). As there was a dubious record as to when the coolant was last changed on the car I insisted she get the system flushed/replaced - may this of led to the thermostat failing? If so could it be the source of the leak (I have no idea where the stat is though...)

Could it be something as simple as heat expansion/contraction and a hose low down on the rad not sighted correctly?

Any advice greatly received - many thanks.

David (in the dog house).

It will more than likely be a leak from one of the hoses, or as it has had the system flushed etc recently could be a failed o ring in the drain tap. Until you know for certain where the leak is from there's little you can do about it yourself. As it is dripping when cold, this means you can feel around under the hoses etc and check the radiator with a torch without fear of being burnt. The key places to check are where the hoses join the pipe just in front of the engine and the two connections at the radiator, and the hoses around the thermostat etc. Remember it is not impossible for a hose itself to have a crack in it and leak. It could even be the radiator leaking.

The thermostat is under the engine cover. The badge clips off and there's another clip to remove, under these are 2x 10mm nuts to undo. The cover then pulls off. IMO stick this cover in the bin remembering to save the spare oil cap from underneath it. The thermostat is rather obvious and bolted to the top right hand side of the engine as you face it. The thermostat itself tends to fail due to a poor design, two plastic clips break, they normally do this themself and unlikely to be cause by flushing.

Don't worry about the thermostat/temp sender for now unless taking it to a garage, the key thing to sort is the leak.

Do the hoses have the original clips on or has the garage replaced one with a jubilee clip? That could be causing the problem.

The coolant is pretty much life long, although bad things happen when blue coolant is added to the original g12. If the coolant the garage put in is blue then this may react with any coolant left over inside the system. I can't see a garage putting much effort into flushing a coolant system (I spent a couple of hours doing my own).

Edited 10 October, 201015 yr by anewman

ok so its had a flush and probs ever since......

.... running cold..... and leaking when cold and not hot..... Im thinking has the thermostat not being refitted..... causing the water to constantly go throu the rad and thus causing it to run cold...... also thinking.... if thermostat has been removed, did they fit the gasket between the two matting surfaces... if not this could be the source of the leak due to different expansion/ contracting rates....

just my pennies worth.......

Edited 11 October, 201015 yr by mudyf0x

I had the same issue.

This is what I did:

1. Changed the thermostat sensors (2 on the rad).

2. Used radweld (and really regret it)

3. Went to a local skoda dealer, got them to inspect it: now the rad and the water pump are leaking. Around 750 to change both (inc parts and labour).

Word of advice: Don't try the cheap stuff, first just get it to a local dealer, they can inspect it for you and tell you exactly what the issue is.

If you went elsewhere a water pump and radiator change would be much less than £750.