Running cool

Hi, so my Clio is running cool, and has been for a few years now so time to sort it. My guess is the thermostat, so have got a new one and intend to replace it tomorrow. Not done this before and I class myself as 'very basic' when it comes to mechanical things i.e. Can do basic stuff. Haynes manual (if I've read it correctly, dangerous I know!) suggest to take off the distributor cap for better access...I've not started looking/mauling about yet. I assume replacing the thermostat is easy (I've done it before on cars in the past...in my twenties when rolling around on the driveway at a weekend was the only way to fix something). Before I start...anything I should watch out for? Thanks (and apologies for sounding like a complete incompetent ****).

So...took bits off the car to get to the thermostat housing...all ok...then decided because I didn't have the rubber O ring that goes around the thermostat to abort the job...sun was out and I didn't want to take off the old one, see that it was perished and then be stuck not being able to use the car whilst the weather is sooooo good. Put it back together and went for a drive!

Have just tried to get a new O ring and can't (tried RPD). Can anyone help? Also, I still need to know if there is another gasket for the thermostat housing as well as the usual O ring? Thanks.

The O ring is supposed to be included in the box with a new thermostat and I've got no idea if it's something you can buy seperately but the part number for it is 77 00 718 380

There is no gasket for the thermostat housing, making sure the mating faces are properly clean is the main thing plus a bead of silicone sealer is what does the job


EDIT: Turns out you can buy it https://www.ebay.co.uk/itm/RENAULT-1...i:153930676166

Perfect, thanks. I'll try and get that part and have some sealant to hand when I get to it.