Coolant Leak In C5

[VadymUK]

Hello everyone, my C5 2002 year reg, 2.0l HDi Auto recently started losing a bit of coolant through the sensor on the coolant reservoir tank. It's not much, just a few drops, but could it be the HG problem in the future?

Also, will gasket sealant sort it out or something else needs to be done?

Edited September 11, 2013 by VadymUK

[paul.h]

Welcome to the forum.

The parts diagrams do not show a separate seal for the level probe so it must be built in to the probe. As a temporary measure you could try gasket sealant and if it does not work then a new probe may be needed. With the probe removed (it may need to be twisted to remove it but this is just a guess) check the tank is not damaged and causing the leak.

 

I have moved this post in to one of the subforums since outside of these they tend to get lost and not be seen.

[VadymUK]

OK,thanx for that, I just noticed today small bubbles of air coming form underneath of coolant level sensor and some hissing noise as well, but this time there was no water leak. The temperature gauge is in the middle normal position, but it seems like lots of pressure building up in the coolant reservoir...

[paul.h]

If you can, this should be sorted as soon as possible. Pressure should build up in the tank as the water heats and expands. The cap is set at 1.4 barg but with your leak the pressure build up will vent through the leak. The coolant will normally go to about 96°C or more and without being pressure tight the water may boil like a kettle - this is when there is a risk of head gasket failure if the cylinder head contains steam instead of water since the heat removal is greatly reduced. The temperature gauge would then not be reliable.

[VadymUK]

OK, I'll take it to garage to do a proper check. Will keep updated.