Constant Thermostat Failures!

[suj]

So this is pissing me off now, as most of you know I do NOT cut corners, I have done everything properly, but it seems another thermostat is now overcooling again!!!!!

In the following thread: http://www.clio197.net/threads/thermostat-change-advice.56208/
I changed my thermostat as it was overcooling, to find it had broken inside:

Here are 2 pics of the last two stats (first one was unknown make, was already in the car when I bought it, I then changed it for a Gates part which is the second picture, which as you know isn't some crap cheap brand, but then that also failed, so I bought a genuine Renault part from RPD which is currently in the car, and it seems that is now failing!)






I drive a lot per day, doing ~75miles (nearly all motorway), but when on a light cruise (say 40mph) the needle moves to between line 2 and 3, I have tracked it on Torque Pro and it goes from 75degrees down to 70-71degrees, then back up to 75, repeat. (In traffic it goes up to 90degrees and then fan kicks in correctly to lower it).

I am so tempted to just throw in a 89degree stat now, as it's really winding me up, but the car came from the factory with a 75degree stat for a reason, I don't want to cause any damage!

I've changed many thermostats before, they've never broke like that!

Anyone able to shed any light please?
Thanks in advance

 

[Timbo]

So, what part of that temperature range seems wrong to you? Very similar to what mine does, and which I am told is the correct operation. When my stat was malfunctioning, it would hardly get to 75C. Now, it warms up to 75, the stat opens, it cools down a couple of degrees...stat closes etc if cruising. If worked hard or in traffic, it will rise, and yes, the thermo fan kicks in at 90C.

 

[suj]

I don't know if it's because the dial is moving about or the range is a bit low?

As normal cars with 89degree stats sit more or less central, now I know temp gauges are a load of crap and not accurate, but normally they go from like 87-91ish (from previous car experiences).

So you think this is totally fine? Am I just over-thinking aka paranoid? lol

 

[Antti O]

I have BEHR aftermarket thermosthat. No any problems with that. Maybe try that next?

My normal running temp:

 

[suj]

Thanks @Antti O yours is a 89 degree stat though, the car came with a 75 degree stat from the factory.

 

[Daverb]

If the 89 is a stronger design i would use that. 75 is a bit cold to me if anything.

 

[Timbo]

The spec calls for a 75C stat. Engineers make these decisions for good reasons, so I'd certainly hesitate in fitting an 89C stat. If you were to do this, it would seem logical also to raise the thermo fan threshold.

 

[Antti O]

Yep there is real reason for cold stat i know that. When my thermosthat was absolute open all the time, we had -25celsius imagine to drive with open thermosthat. How warm car was?
Genuine thermosthat was backorder from France 1 months, and behr thermosthat was next day delivery. Also one reason for little hotter thermosthat was that our winters are really cold and every bit of heat you will get cabin helps.
I have drove whole summer +25c hottest days and never had any problems with heat issues.
I do recommend also original if those are fine, but behr little bit hotter is one option.

 

[Antti O]

There seems to be lot of not genuine 75c thermosthat available..for example Valeo.

https://www.pkwteile.de/autoteile/renault-ersatzteile/clio-iii-br0-1-cr0-1/19355/10195/thermostat

 

[Big Ben]

Suj I'm certain my car runs at the same marker points on dash as yours does.
Don't think there's an issue. I'm really happy with mine

 

[turkie172]

Well it can be one of these things either the thermostat is fitted the wrong way round/ incorrectly lined up or the water pump is wrong in some way and is pumping at a much higher rate the drive pulley is larger on the aux belt or some sort of restriction in the cooling system even that the compression in the cylinders is leaking into the cooling system normally you might hear a slosh in the heater matrix on start-up. I cant understand how if the thermostat fell apart like the first picture how you managed to still have the parts they would have went through the system and for the genuine part I had it changed a year ago and I think there is something funny about it as it does not act like the Clio 172 engine that the temp never moved from just over half way the 197 goes almost to the half way mark the thermostat opens then the temp drops back to just above the second mark and not until you are stationary does the temp rise to the half way mark and the fan comes on.

Check this video fitting thermostat to a clio 197 the first thermostat you removed might have been the wrong way round to begin with

Check the cooling fan is not running all the time or kicking in too early I need to check the temp sensors there is one for the dash and I think one for the fan I'll check this out and get back to you.

PS. I think there was a Clio cup racing mod where a small bypass hole was drilled in the thermostat but I think this was for reducing temp or pressure in the system when the thermostat is closed.

 

[VolumeX]

From what I know the Clio 200 thermo is 90 and guys buy the 75 unit....

 

[Timbo]

From what I know the Clio 200 thermo is 90 and guys buy the 75 unit....

No, genuine Renault stat for 200 is 75C unit


Sent from my iPad using Tapatalk

 

[youngarthur]

I have BEHR aftermarket thermosthat. No any problems with that. Maybe try that next?

My normal running temp:

This is also my running temperature on my meg engine Clio.Its fine for the road, but on track,I open the bonnet louvres, and remove number plate, where more holes are cut. I have also removed the rubber strip, that runs at the bottom of the windscreen valance.Just in case, I have an override switch for the cooling fan. Goodbye over heating!.

 

[suj]

There seems to be lot of not genuine 75c thermosthat available..for example Valeo.

https://www.pkwteile.de/autoteile/renault-ersatzteile/clio-iii-br0-1-cr0-1/19355/10195/thermostat

Yeah I bought a 75 degree Gates one.
The non-RS MK3 shares the same part with 172/182 clios, so that is why there are many 89degree stats, the 197 and 200 run 75degree stats.

Well it can be one of these things either the thermostat is fitted the wrong way round/ incorrectly lined up or the water pump is wrong in some way and is pumping at a much higher rate the drive pulley is larger on the aux belt or some sort of restriction in the cooling system even that the compression in the cylinders is leaking into the cooling system normally you might hear a slosh in the heater matrix on start-up. I cant understand how if the thermostat fell apart like the first picture how you managed to still have the parts they would have went through the system and for the genuine part I had it changed a year ago and I think there is something funny about it as it does not act like the Clio 172 engine that the temp never moved from just over half way the 197 goes almost to the half way mark the thermostat opens then the temp drops back to just above the second mark and not until you are stationary does the temp rise to the half way mark and the fan comes on.

Check this video fitting thermostat to a clio 197 the first thermostat you removed might have been the wrong way round to begin with

Check the cooling fan is not running all the time or kicking in too early I need to check the temp sensors there is one for the dash and I think one for the fan I'll check this out and get back to you.

PS. I think there was a Clio cup racing mod where a small bypass hole was drilled in the thermostat but I think this was for reducing temp or pressure in the system when the thermostat is closed.

I'll try and answer some of them in points, as there is a lot of text
1) you can't fit it the wrong way round, the housing part will now allow you to do so
2) the car doesn't use / lose any coolant, no sloshing, temperature inside is nice and hot when you set it to that
3) yes I was worried about the parts getting in, but all the parts were intact and nothing missing, so that confused me too!
4) 172 runs a 89degree stat, so it will sit bang on in the middle, temperature gauges are not the most accurate or linear, so on a 172 it will range from like 87-92degrees, but still sit in the middle.
5) If you click the link I posted at top, I used that guide, like I said above, you cannot fit it the wrong way round.
6) They do the hole on many track cars, it's because they are driving high load all the time, that's not a solution to a road car lol.

From what I know the Clio 200 thermo is 90 and guys buy the 75 unit....

No, genuine Renault stat for 200 is 75C unit


Sent from my iPad using Tapatalk

As timbo said, 197 and 200s run 75degree stats, not 89.

Suj I'm certain my car runs at the same marker points on dash as yours does.
Don't think there's an issue. I'm really happy with mine

Yeah I am starting to think that too Ben, maybe I'm just paranoid lol.

This is also my running temperature on my meg engine Clio.Its fine for the road, but on track,I open the bonnet louvres, and remove number plate, where more holes are cut. I have also removed the rubber strip, that runs at the bottom of the windscreen valance.Just in case, I have an override switch for the cooling fan. Goodbye over heating!.

Yeah Megane engines rub 89degree stats too, so they'd sit same as Antti's does.




So I did write in the link I posted, but forgot to say here, my car never overheats, fan kicks in as it should etc.
The pipe coming off the thermostat housing, it was kinked as it was slightly crushed under the knock sensor, I didn't notice it on the first stat change, as I didn't move the housing out loads, but when I put the OEM part in, I noticed it, and now it is free, so I'm hoping it was this, but I'm just paranoid, as I don't want to kill any engine or nothing!

Thanks for all the replies and putting my mind at ease guys

 

[sevenfourate]

Fingers, toes and eyes crossed suj

Keep us informed......

 

[Paul222]

Interesting thread Suj, I've not had my 197 long and posted a thread about the temperature gauge/fan kicking in as it seems odd but I guess it's just normal then? How often/when does your fan kick in?
I've ordered a new thermostat from Renault parts direct which I'm going to fit when I service it just for piece of mind. My fan seems to kick in really early to me.

Here's my thread http://www.clio197.net/threads/engine-fan-cutting-in.57492/

 

[Timbo]

This is also my running temperature on my meg engine Clio.Its fine for the road, but on track,I open the bonnet louvres, and remove number plate, where more holes are cut. I have also removed the rubber strip, that runs at the bottom of the windscreen valance.Just in case, I have an override switch for the cooling fan. Goodbye over heating!.

I see quite high oil temps (up to 120C, via the RS Monitor) when tracking my 200 Cup. However, coolant never gets above 93C (DashCommand). Initially, I was concerned about the oil temps but was told by an experienced Renault tech that (a) the RS Monitor reported oil temp is actually "calculated" (ie, not reported from a sensor) and (b) that oils meeting Renault's spec (and especially Renault's recommended Elf oil) could easily cope with that sort of temperature.

 

[suj]

Fingers, toes and eyes crossed suj

Same Shuv, I guess I am used to 89degree stats, so then the gauge is dead central.
It's made me feel better knowing others are the same. (Or all our thermostats are ruined lol haha )

Keep us informed......

Interesting thread Suj, I've not had my 197 long and posted a thread about the temperature gauge/fan kicking in as it seems odd but I guess it's just normal then? How often/when does your fan kick in?
I've ordered a new thermostat from Renault parts direct which I'm going to fit when I service it just for piece of mind. My fan seems to kick in really early to me.

Here's my thread http://www.clio197.net/threads/engine-fan-cutting-in.57492/

Just had a read, no my fan doesn't kick in loads, just normal I'd say like others, when it's really hot in traffic.

AC brings the fan on, so try running with AC off, see if it makes a difference maybe?

 

[Paul222]

Just had a read, no my fan doesn't kick in loads, just normal I'd say like others, when it's really hot in traffic.

AC brings the fan on, so try running with AC off, see if it makes a difference maybe?

Thanks for the reply, the air con is off when the fan comes on. Is there a fan switch which could be faulty maybe? Seems odd how it comes on so quickly even when not in traffic. I'll change the stat and see what happens! Cheers