Hi all, quick question.

 

I have noticed my coolant has dropped in the last 5 months. Around 0.5 inches to 1 inch. It used to sit between the low and max mark and is now just below the minimum mark when cold (I have ordered more to top up)

 

I am sure there is no leak anywhere, however I did buy a black expansion bottle cap from ebay around 5 months ago, I wanted black instead of blue. It probably isn't a genuine one. Is it possible this cap is to blame? Maybe a faulty pressure valve causing excess evaporation or something?

 

Cheers all

That's a common fault on many cars, leaky cap. Try switching to a genuine one Maybe you even have your old one laying around?

Hi, I have placed my old one back on and see how it goes once I manage to top up. I just wondered if the expansion cap can be at fault.

I’m getting the same problem on mine. Mines the diesel 2 litre. 

Ive has a look in all the places where it could leak from. There’s no trace of any leaks at all. Even the garage can’t find the problem!

17 minutes ago, Stuart-h said:

I’m getting the same problem on mine. Mines the diesel 2 litre. 

Ive has a look in all the places where it could leak from. There’s no trace of any leaks at all. Even the garage can’t find the problem!

 

What age of engine?- I seem to remember there was a version of the 2.0 diesel that could suffer with a porus head.

 

Any staining on the radiator especially where the plastic side tanks join the cooling pipes/vanes - look carefully front and rear for an purple/pink -  Also check plastic pipe connectors into the radiator - the O rings can also degrade. If these are ever disturbed they MUST be replaced. It's tightly packed in so you might need an inspection camera.

 

Header tanks can crack with age (not always obvious)  -  and the heater matrix can degrade.

 

Edited 29 November, 20187 yr by bigjohn

It’s the 2013 engine. I can’t remember the code for the engine off the top of my head. 

 

Funney you should say about the expansion tank. Had one split on my mark 2 octivia !