Constant Thermostat Failures!

Maybe get an OBD tool to determine the temperature at which it cuts in first. Should be 90C and if that's what's happening, it's not a stat problem (indeed, if there's no other cooling problem, a broken stat is most likely to have the car running too cool more often than not. That said, it seems these Renault 70C stats have a life of c.5-7 years. If you change it, it's also worth doing a full coolant flush and change.
 
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Maybe get an OBD tool to determine the temperature at which it cuts in first. Should be 90C and if that's what's happening, it's not a stat problem (indeed, if there's no other cooling problem, a broken stat is most likely to have the car running too cool more often than not. That said, it seems these Renault 70C stats have a life of c.5-7 years. If you change it, it's also worth doing a full coolant flush and change.

Ideal thanks for the information. I'll look into doing that. Sorry for hijacking the thread
 
It's a 75 degree stat because the rad is tiny. I'm fitting a meg rad with the conversion, it's so much bigger!

So it's constantly flowing coolant through with the 75 degree one.


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Sorry for hijacking an old thread, I have thermostat issues. When I bought my car almost a year ago the stat was knackered, in between first and 2nd line. Had it changed last year but this winter killed it. It would fluctuate between 2nd and 3rd, Torque Lite said its sitting around 68-72 so not awful. In colder weather (4 degrees or lower) it seemed to struggle to get above 65. Garage changed it and said its the same, now with slightly warmer weather it sits nearer to the 3rd line. As the dash temp gauges this will only be 75-80ish. I have NEVER seen it hit the 3rd line, and I sit in traffic all the time. It doesnt seem right to keep it cool all the time? You would get hot and cold parts, hot spots, and oil is designed to work best over 90 degrees.

Has anyone fitted a 182 stat? Its not like it gets hot in the UK!
 
So I used to think mine was broken, but it wasn't.
It's meant to fluctuate between 2nd and 3rd line, as the third line to the middle-ish is about 80-95 degrees (give or take) so it's not ideal as the guage doesn't read super accurate.

It's a 75 degree stat, so while moving it was at 75, then it will go to 76-77 and open and drop down to like 72, then repeat. 90 degree stats do exactly the same, but as they go from 92>85ish (like I said earlier, in the central range) you wouldn't see the needle move so much or at all.

Also the fans kick in at like 90 degrees, so that is why when stationary it will peak higher, so that again is normal.

I had come from cars with 90 degree stats, so this was new to me.

I bought a genuine one and it's been fine since, I have logged my temperature for many many miles (paranoia).

Renault designed the engines to run 75 degree stats for a reason, I wouldn't put a 182 90degree stat on, I think I'd trust Renault over a few people who have put the higher temperature stats on lol.
 
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So kids. Bit of a thread rekindle here....... Currently having a discussion with someone on Facebook:

Screenshot_20181010-191018_Facebook.jpg

So what's best.....
Is the 90 best because of what this lad says? Or is a 75 one best because that's what's fitted standard?
 
Go with stock thermostat, it only starts opening at 75 and ends (is fully open) at 87 on the F4R 830/832, I'm sure there must be a reason for it! Most of other Mk III engines us thermostats that open at 89 but they don't have engine bays as packed as the RS

The part number is 8200772994
 
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It was designed to run lower to make power, you are right it might get you better MPG on a 89degree stat, but won't be as responsive regardless of what people say.

Like me, it was the first time I had such a low stat, so it was daunting in my first winter seeing the needle move about, but after researching it is fine. My BMW 740iL had an electronic stat that worked way past 90 degrees on a cruise for better MPG so that was odd too!

Also you do track days, so I think it makes sense alone to get the lower stat (the Mégane engine lot use these stats on their track cars for example).
 
I know it will retard the timing when its too hot, losing power and making it run hot. However, what I have found is in the winter even a thermostat only 6-12 months old is not strong enough to run at a decent temp for normal driving. Last winter I saw temps of 65 degrees at times when it was cold when commuting. That just seems a waste to me and if a 90 degree stat from Renault is just as sh*t it will run cooler than it should.

It depends how you drive. Driving hard a 90 degree stat makes no sense. Even in normal temps (10-15 degrees - you know you're British when over 15 degrees is hot!) it doesnt make sense with our engine but in winter and for 90% commuting, I can see the relevance, even though Renault fitted a 75 degree stat.

I plan to try a 90 degree stat, just to try over winter and Ill monitor temps. My car is currently 90% commuting and 10% fun.
 
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I know it will retard the timing when its too hot, losing power and making it run hot. However, what I have found is in the winter even a thermostat only 6-12 months old is not strong enough to run at a decent temp for normal driving. Last winter I saw temps of 65 degrees at times when it was cold when commuting. That just seems a waste to me and if a 90 degree stat from Renault is just as sh*t it will run cooler than it should.

It depends how you drive. Driving hard a 90 degree stat makes no sense. Even in normal temps (10-15 degrees - you know you're British when over 15 degrees is hot!) it doesnt make sense with our engine but in winter and for 90% commuting, I can see the relevance, even though Renault fitted a 75 degree stat.

I plan to try a 90 degree stat, just to try over winter and Ill monitor temps. My car is currently 90% commuting and 10% fun.

This is exactly what I was thinking the other day, now the temps have dropped in the morning to 2-3degrees when I go work, it has been sitting low.
So I was considering using a 89degree stat to see how it affects things.
 
This is exactly what I was thinking the other day, now the temps have dropped in the morning to 2-3degrees when I go work, it has been sitting low.
So I was considering using a 89degree stat to see how it affects things.

Worst case scenario the fan will run more. I doubt its going to overheat and its not a massively expensive part to replace.
 
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I'm generally only getting between 60-65 daily driving.
Which is what's led me to believe mines stuck open