Any weak points in the 197 cooling system?

[Helpimonfire]

So I'm working away and the missus is using the Clio while hers is being repaired and I get this text this morning...


I checked the coolant level recently and it was just slightly below the maximum mark while stone cold, not noticed any leaks but is there any weak points that could be causing this? I won't be able to look until later this week so I'm trying to work out what it could be.

 

[RSRowe]

The cooling system is pretty reliable tbh. Unfortunately no one can really help you without further info.

Though I certainly wouldn’t recommend driving it.

 

[Foxspeed]

thermostats break/go faulty and the cooling fan can sometimes stop working as the wiring pulls out of the bottom of the fuse block...

 

[Frank Perry]

@Foxspeed is it the stat or the housing?

I think I have a super slow coolant leak out the housing but not sure if the housings normally fail or is it's the gasket?

Wondering if this could be the same for @Helpimonfire too?

 

[suj]

@Foxspeed is it the stat or the housing?

I think I have a super slow coolant leak out the housing but not sure if the housings normally fail or is it's the gasket?

Wondering if this could be the same for @Helpimonfire too?

Frank it's the thermostat that normally fails, in 4 years I've had 2 fail (first one was a good aftermarket as needed it ASAP, second one was genuine, been fine since).

It might be the gasket on it that's failed (as it sandwiches between the housing and the engine).

If you take out the cold feed to the slam panel you can get better access to seeing it.

 

[Frank Perry]

Cheers @suj - If I removed the battery and housing I can assume this would provide plenty of access to get it replaced.

Mine isn't specifically showing any signs of failure but I'm just looking to do some preventative maintenance!

 

[suj]

Yep battery out, battery box out (pain in the ass to get out and back in right haha), then you got access to the 3 bolts on the housing, once off just remember orientation of the thermostat (you cannot put it the wrong way....you'll see when you do it).

If it's not gone, I wouldn't worry as it's getting colder too you won't have a problem, but like I mentioned just buy a genuine Renault one (also Clio 197 runs a 75degree thermostat, 172/182 run a 89degree one, some people have put them into their 197s, but I personally don't see the point as Renault designed it as a 75degree one for a reason).

 

[Helpimonfire]

@Foxspeed is it the stat or the housing?

I think I have a super slow coolant leak out the housing but not sure if the housings normally fail or is it's the gasket?

Wondering if this could be the same for @Helpimonfire too?

I think I got to the bottom of it even though I've not been home yet. I remember a few years ago my mechanic mentioned that the fan cowling was rubbing on the bottom radiator hose. I got my missus to fill the expansion tank up to the brim before she used my other car to go to work (long story ) and when she got home is was empty. So I think the rad hose was finally worn through.

New one on order. Even if it doesn't solve it, it needed doing eventually! Updates to follow.

 

[Frank Perry]

I think I got to the bottom of it even though I've not been home yet. I remember a few years ago my mechanic mentioned that the fan cowling was rubbing on the bottom radiator hose. I got my missus to fill the expansion tank up to the brim before she used my other car to go to work (long story ) and when she got home is was empty. So I think the rad hose was finally worn through.

New one on order. Even if it doesn't solve it, it needed doing eventually! Updates to follow.

Glad you have a starting point there - sounds like you're onto something!

@suj you're a legend, thanks a lot mate!

 

[Helpimonfire]

So a little update on this.

I bought a cooling system pressure testing kit to see if I could force a leak. Nothing. Kept an eye on the level and it stayed the same for a couple weeks so I put it down to a one off but I've been checking anyway regardless. Got to work yesterday morning and as I was pulling into the yard I could hear a gurgling from behind the dash, didn't think too much off it as I couldn't work out what it was and as I park under my bosses bedroom window I didn't wanna leave it running and poke about under the bonnet.
Forgot about it until I left work and heard the sound again, at the time I didn't realise it was a gurgling noise, almost sounded like a pulley failing so didn't think about the coolant situation. Got home fine (I live literally 5 minutes from work) and left the car to cool overnight. Checked this morning and I was greeted to an empty expansion tank. Topped up with 2 litres of water and pressure tested it again. Ran it up to temp and kept checking for leaks. The gurgling was still there so out came a 10mm and a flathead to bleed the system. There was SO MUCH air in the heater matrix which kind of explains why the heater hasn't been that great since the timing belt and waterpump change. I have a feeling there's been a massive air bubble in the system for ages and it only reared its ugly head while the missus was running it to work and back (22 miles each way). Surprised it survived the sprint event really.

Anyway. We'll see what happens next. I just can't find anything that would indicate a problem. I'm gunna let it cool off again (and stop raining!) and change the thermostat and o-ring, then dump all the coolant, change the lower rad hose and go from there.

 

[turkie172]

When I had a 106xsi if you started up and heard a slosh behind the dash it was the head gasket also check under the carpet inside as the heater matrix could be leaking inside the car. Two liters (think the system is 5L total) is a problem use the proper Type d coolant it's that funny color for a reason that's to identify leaks using straight water coming into winter is going to be a problem the hose down the front of the engine under the oil filter can rub on the block I spotted mine and took care of it early. It will be better if you find a leak around the engine bay thermostat and pump housing because if its inside the engine that will be a pain. Also look for a wet radiator can be a sign of a leak, you pressure tester might keep it connected when engine is running and up to temp see if it has funny readings you will need the system fully open so above 75-80 Degrees for a better test The manual seems to say a yellow marking cap is 1.4bar so testing can go up to 1.3bar 0.1bar under max.

 

[DS197]

When I had a 106xsi if you started up and heard a slosh behind the dash it was the head gasket also check under the carpet inside as the heater matrix could be leaking inside the car. Two liters (think the system is 5L total) is a problem use the proper Type d coolant it's that funny color for a reason that's to identify leaks using straight water coming into winter is going to be a problem the hose down the front of the engine under the oil filter can rub on the block I spotted mine and took care of it early. It will be better if you find a leak around the engine bay thermostat and pump housing because if its inside the engine that will be a pain. Also look for a wet radiator can be a sign of a leak, you pressure tester might keep it connected when engine is running and up to temp see if it has funny readings you will need the system fully open so above 75-80 Degrees for a better test The manual seems to say a yellow marking cap is 1.4bar so testing can go up to 1.3bar 0.1bar under max.
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Same issue with a 206 and the heater matrix. Half a bottle of Radwell fixed it for over 4 years until it eventually had to be replaced.

Definitely run your hand through the carpet on both sides as you might not see any coolant leaks. Heater matrix faults aren’t heard of on these but better ruling it out and concentrating elsewhere.

 

[Helpimonfire]

That had crossed my mind but I've found no water inside, not even under the carpets. It doesn't seem to use water slowly, it just seems to go in one hit. Almost like it's getting too hot and just dumps it. It's showing no signs of head gasket failure but I'll be keeping an eye on it, the heater works really well now that I've bled it and there's no sign of water/oil mixing. Even the exhaust gases seem really clean and smell normal.

Completely stumped. It's gunna be something really simple, just watch