200: Gurgling water noise behind dash

[littleg78]

I’ve heard a gurgling water noise from behind the centre console of the dash, when I start the engine, for as long as I can remember (probably since I bought it) - read the forums about scuttle drains and bleeding air bubbles from cooling system so finally had a proper look yesterday.

Good news: Scuttle drains clean and flowing freely!

Bad news: No coolant in the reservoir!

It’s just had a “Full” service from a local Renaultsport specialist so was pretty surprised that fluids were low - obviously wasn’t checked.

Quick trip to Halfords for some of their OAT coolant, and it drank just over a litre. I only opened the plastic valve by the firewall to bleed but got a fair bit of air out. Took the car for a run last night, and this morning the level in the tank is a bit lower so topped up to max. It’s taken almost a litre and a half in total.

Engine temp has always been stable, and gurgling noise on startup has now gone. I’ll keep a close eye on the coolant level from now on!

I’d like to have it checked by a professional (if I can find one!) but is there anything easy or obvious that I should check myself for leaks etc?

 

[RossWoods93]

Morning mate!

I had exactly the same issue on my Clio, sound like someone chucking a litre bottle of fluid behind the center console!

I took mine to Renault to go into for diagnostics and they found my coolant leak was a crack on the thermostat housing.

Replaced the thermostat housing and all was good! Hope you get it sorted quickly!

 

[littleg78]

Coolant level still dropping very slowly, but have recently spotted coolant pooling beneath the thermostat housing.

Going to pressure test the system as a next step and check for leaks around that area.

There’s dried coolant EVERYWHERE so hoping there will be a fairly obvious leak!

 

[Frank Perry]

I had a similar looking bay with coolant pool in the same place (ontop of the box I think?) - I had a small split in my thermostat seal. Noticed my temp levels were a bit low as well so after a new (genuine) thermostat, it has been spot on and no more leaks since.

If you find yours is leaking from the housing due to a failed housing gasket, give me a shout as I bought the housing gasket at the same time and realised I didn't need it. It's a genuine gasket, you can have it for whatever half of the cost would be from RDP.

 

[Helpimonfire]

I also had this, mine ended up being (so far anyway...) a crack in the bottom of the header tank. But bizarrely mine only leaks when it gets really hot. I've got a new one to fit soon so we'll see what happens. It's been in daily use for a few weeks now and it's not done it since so I'm not sure what/why it does the things it does. French cars, hey?

 

[littleg78]

I was worried in case it only leaks when when it gets really hot and things expand, but luckily it revealed itself today after sitting for an hour at 1.5 bar... and it’s even in a place where I can easily see it!

Guessing it’s the thermostat seal so I’ll get a new genuine thermostat ordered up!

Any tips about the easiest/cleanest way to drain the enough coolant to change the thermostat?

 

[suj]

When you pull off that housing, it will drain quite a fair bit, just make sure you put the correct coolant in (yours being red, not green).
2 bleed points, on the housing and where the pipes go into the bulk head for the heater (right hand side one has a plastic bleed valve, be careful with it).

 

[Frank Perry]

Glad you found the cause! @suj (the legend himself) wrote a quick guide in PM for me on how to do the thermostat - I've only copied and pasted it here just in case it helps:

1) Take off all the crap so you can get access to it (battery, battery box, airbox intake pipes etc).
2) 3 bolts (10mm from memory) on the thermostat cover
3) change thermostat for new one (some people put Vaseline on the thermostat rubber seal, I haven't done this)
4) reassemble, top up coolant
5) run car with your heaters set to the hottest setting in temp (only need fan on 1) then open the valve on the heater matrix pipe (right at the back on bulkhead, there are 2 pipes, you'll see a bleed valve on the right side one)
6) keep opening this periodically to check if air is coming out

You're then good to go.

Looks like you know what you're doing already though.

 

[suj]

I'm glad it helped @Frank Perry I knew it would only be the thermostat seal that failed

 

[littleg78]

New Thermostat arrived from RPD this morning... didn’t expect it until Monday, so really happy to get it swapped out this afternoon!!!

Not too messy a job - and all dry after a 30 minute drive. Old thermostat seal was properly knackered.

Thanks everyone for the help on this one - picture of the offending item below!