Renault Megane water sloshing sound?!

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Wed 21 Jul 2004 18:34
Renault Megane water sloshing sound?! - RobM
I have a '99 T-Registered Renault Megane that has recently started to make a sort of sloshing water noise, it comes from the front near side of the car, but i can't pin it down further.

It is most prevalent when you first start the engine (especially so if the engine is cold) and if the engine is revved. At first I thought it was some fault with the air-con, as it seemed to happen when the air-con is being used, however due to the recent wonderful weather I haven't used the air-con for a while and the noise is still there!

After a short drive the sound is completely gone. There are no obvious water leaks I can see, the washer bottle is on the other side of the car, and the expansion tank level is consistent (when I've checked both engine warm and cold), and the car isn't overheating at all.

Any suggestions any of you may have greatly appreciated!
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Wed 21 Jul 2004 18:35
Renault Megane water sloshing sound?! - SjB {P}
Air lock in the heater matrix?
Have you tested heater output to check it is working well?
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Wed 21 Jul 2004 18:57
Renault Megane water sloshing sound?! - Stuartli
Might sound silly (no pun intended) but quite often noises don't always originate in a car from where you assume/think.
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Wed 21 Jul 2004 19:09
Renault Megane water sloshing sound?! - RobM
Just been out for a drive in the car and had the heater on, the output is fine, gradually from the middle to the hottest setting. I've got one way around this annoyance - making sure i've got the radio on loud enough so I don't hear it!
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Wed 21 Jul 2004 19:21
Renault Megane water sloshing sound?! - SjB {P}
Okay, next test, as it still sounds to me like an air problem.

If you squeeze the coolant hoses (carefully if they are hot!), do you feel any resistance, and see the water in the expansion tank 'react'? Repeat hot and cold. If you do see a reaction, it's back to square one, but if not, it is likely to imply that air is in the system.
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Thu 22 Jul 2004 16:50
Renault Megane water sloshing sound?! - Big John
I agree that it sounds like an air lock, probably air in the heater matrix. It needs to be investigated, if you ignore it you could be asking for a head gasket failure - or worse. Look out for bleed vlaves on high points of the cooling system (including heater matrix feed pipes) to release any air, keep coolant topped up!

NB Fiat Puntos are very prone to this as the expansion/filler tank feeds the BOTTOM of the system, this is probably why so many people report head gasket failures after a coolant replacement service.
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