Coolant loss

[PapaXray96]

Hi all. I’ve been having an issue with coolant but I’ve not managed to find a thread that matches my issue. 

My coolant warning light started coming on after long journeys but when I’d unscrew the filler cap the tank would depressurise and refill. It now comes on minutes after I start the engine and doesn’t refill completely when I take the cap off. I’ve also recetly noticed a leak around the temp sender on the radiator though it doesn’t seem bad enough to account for the loss in coolant. Any ideas?

[Breezy_Pete]

Radiator thermoswitch is a very common spot for coolant leaks on the Mk1 Fabia. Can be resolved by simply tightening it up a little. Access is a little awkward, and space  for swinging a tool is limited, but either a 29mm deep socket on it, or an open-ended spanner/adjustable. For the latter you may need to remove the fan for better access. Official torque figure is only 30Nm, so don't gorilla it too much.

 

What year is your car, and which engine code?

 

Try removing the expansion tank cap before starting the engine this morning, listening for residual pressure.

[PapaXray96]

Thanks for replying Wino. I removed the cap this morning, baring in mind I have not driven her since Thursday evening, and there was a hiss and air bubbles from the bottom hose into the tank. Gave it a sniff and smelt suspiciously like exhaust gases. 

 

She’s a 2006 1.2htp (47hp)

Engine code: BME

 

Just topped her up and got her up to temp with no change in coolant level, seems to only drop under load.

[stuart vrs]

Same symptoms on my vrs 06 plate, every morning the warning light beeps and stays on for duration of journey (30 mins) when leaving from work I release the pressure and get no warning beeps. Is the thermostat sticking or is it the sensor in the bottle. I'll smell the cap tomorrow, I've got no oil in the expansion tank or Mayo on the oil cap. It has got 168k mind. 

 

[sepulchrave]

You both have blown head gaskets, if there's pressure in the system after the cars been sat all night it's the head gasket, end of story.

[stuart vrs]

Would I not have oil in the coolant and Mayo on the cap, recent oil change and nothing unto the ordinary. It's been doing this on and off for 6 years. 

[KenONeill]

@stuart vrs Mayo in the rocker cover proves that there is condensation there. There is more than one cause of condensation in rocker covers, so it is not diagnostic of HGF in itself.

 

Is your coolant light more likely to throw when the weather is cold than when it's hot? If so, then I'd suspect that you need to do a level prong scraping if they're visible through the cap, or replace the expansion bottle, about £15 if they're not.

[sepulchrave]

On 08/09/2018 at 21:28, stuart vrs said:

...I've got no oil in the expansion tank or Mayo on the oil cap. It has got 168k mind. 

 

 

That's because it's only the combustion gases entering the water jacket.

 

17 hours ago, stuart vrs said:

Would I not have oil in the coolant and Mayo on the cap, recent oil change and nothing unto the ordinary. It's been doing this on and off for 6 years. 

 

You're repeating yourself, this is textbook denial, I suspect in six years of not fixing the problem it's frankly become a mantra.

 

You have head lift, it's incredibly common, the cure is to replace the head gasket and use PD150 bolts to prevent it happening again.

 

Or just keep on driving until the engine finally cooks itself due to blowing its load on the M4 somewhere.

[stuart vrs]

On 14 September 2018 at 15:48, sepulchrave said:

 

That's because it's only the combustion gases entering the water jacket.

 

 

You're repeating yourself, this is textbook denial, I suspect in six years of not fixing the problem it's frankly become a mantra.

 

You have head lift, it's incredibly common, the cure is to replace the head gasket and use PD150 bolts to prevent it happening again.

 

Or just keep on driving until the engine finally cooks itself due to blowing its load on the M4 somewhere.

Ok pal.