[ryan21]

Hi, I have just checked my coolant level and when iv removed the cap and looked into the expansion tank there seems to be a build up of sludge? The coolant hasn't turned to a milky colour and is still orange.

Is this anything to worry about or has anyone else had this issue?

Thanks

 

[Jason Sullivan]

Do the particles look oily and is there a sweet smell when the car is ticking over ?

 

[ryan21]

Do the particles look oily and is there a sweet smell when the car is ticking over ?

No the particles aren't oily, it's like a limescale round the outer of the tank sorry its hard to describe. It does have a coolant smell when engine is warm.

The car had a coolant leak and the radiator was changed in March this year.

 

[Jason Sullivan]

It could well be head gasket that header tank looks like my mates MK3 RS when his HG went

 

[ryan21]

Alright thanks for that. I'm going to ring dealer first thing hopefully its covered under warranty.

There has been no other signs and car has been running perfect only realised as I'm going away Thursday so was just double checking everything before we leave.

 

[Jason Sullivan]

Hopefully it’s not mate there was a recall issue on all RS’s with the HG so it was common for a lot of engines to fail but not heard of many MK3 ST’s failing 🤞

 

[lc69]

If you suspect HG issues, you can test for hydrocarbons in the coolant.

Block Tester BT-500 Combustion Leak Test Kit : Amazon.co.uk: Automotive

Buy Block Tester BT-500 Combustion Leak Test Kit at Amazon UK. Free delivery on eligible orders.

www.amazon.co.uk

 

[teflonbilly]

It could just be that a previous owner has topped it up with tap water.

 

[NickFST3]

If the radiator was changed & they flushed it through before removing it likely any sludge & muck was flushed through into the header tank. My first thought would be to take the tank off and give it a good clean. Top it up with fresh coolant & see if the muck comes back. Probably won't. If you were driving around with a blown head gasket or similar you would know by now & the least worry would be some muck in your header tank!!