As all you Cinq owners know our little cars are prone to running a bit on the hot side and theres not really a lot to be done for this except keep the system clean and maybe an aluminium radiator, but if the water gets there hot already its got its work cut out.

As I ran Renault 5 GT Turbo's for many years which can also suffer from having a hot engine bay I thought I would apply some knowledge gained from my ownership with regards to the Cinq.

Now there are no copper core radiators that I've seen (all 5's should have one)which are best for cooling but a simple and effective way of keeping things cool is to have lower temperature thermostats, this is even more relevant if you run lots of mods or especially turbos where the heat under the bonnet gets high. As an experiment i ran the car with no thermostat at all, and the cooling system, although fairly cold at the moment proved to be very efficient never letting my car get above about 55degrees and taking a long time stationary to get hot enough for the fan to kick in, so alls well in that department, but we can't run with no thermostat as the car wouldn't function to well.

So on investigation when I removed thermostat (located on the head) it doesn't open until 96degrees which is a bit on the high side for me leaving the cooling system to play catch up, so I headed off to Halfords and hunted through all the thermostats available on the shelf, taking note that the vast majority open at 88 some 86 and a few at 82degrees , ideal for my purposes (on the 5 they now run 78degree thermostats but its far to big to consider)

I then purchased a 82degree thermostat (think item code is HTK602, no idea what car its from) that looked like it would fulfil my purposes as it looked like the same diameter and length and opened in the correct direction, with the intention of dismantling it and using it & using the parts to rebuild into the Cinq housing which is unique (why is that when 90% of all thermostats are the same shape?)

This was time consuming and tricky but achievable and I now have a working 82degree thermostat which I think will give the cooling system a fairer chance of keeping everything cool. If anyone does this make sure you test the operation in a pot of water that you put on the cooker to raise the temperature to watch it opening, then let the water cool to watch it close again, don't just put it back on the car without prior testing.

I started this not really thinking about how useful the info is so managed to get a couple of photos taken before my battery died.

In this 1st pic you can see a complete Cinq thermostat in its housing, the spring and actual thermostatic device from another Cinq thermostat I had, and the new donor thermostat.


in this pic you can see the reassembled Cinq thermostat with the dismantled donor thermostat and the thermostatic device and spring (which has rolled off to the back)


I hope that all makes sense, but if there are any points anyone would like to ask then please do.

Aaron.

Don't want to diss your post but is a manual fan overide switch not as good? Or if you forget is it goodbye HG?

Liam

Isn't 55 degrees wildy inefficient

I was always told that 90 degrees is optimum...

The 82 degree thermo seems quite good, like you said they sometimes run a little over 90 with the standard one. Mine has just had alot changed and now runs at a constant 85, but it takes a little longer to heat up....Compared to when it had a blown head gasket anyways.

bloomfieldliam said:

Don't want to diss your post but is a manual fan overide switch not as good? Or if you forget is it goodbye HG?

Liam

Click to expand...

No because the fan can't control the temperature in the block! The thermostat opens at 96degrees then how can the fan help, think about it.

Aaron.

joecinq said:

Isn't 55 degrees wildy inefficient

I was always told that 90 degrees is optimum...

The 82 degree thermo seems quite good, like you said they sometimes run a little over 90 with the standard one. Mine has just had alot changed and now runs at a constant 85, but it takes a little longer to heat up....Compared to when it had a blown head gasket anyways.

Click to expand...

Exactly, why do you think I made a lower temperature opening thermostat. the gauge only reads from one part of the engine so is therefore wildly inaccurate, only a thermostat is accurate.

As I said, when you upgrade to maybe a turbo 96degreees is far to high to open, no turbo car should open so late as the cooling system is playing catch up by that point.

Aaron.

Back in the days when I used to rally a very heavily tuned 998cc Imp the std thermostat was an 88deg unit, and despite being all aluminium the Imp lump used to get a bit warm, and I always found an 82deg thermostat gave much better overall performance. (Although it never gave the heater a chance to work )

Nowadays in the Sylva, I use a (very hard to get hold of) 70deg thermostat so I'm getting the absolute best power output. As Rallycinq will tell you, Rallying or Racing causes the most unbelieveable stresses on an engine, (far higher than anything you'd get on the road) with a resultant increase in heat generation, and so a lower rating thermostat gives the engine a much better chance of running at peak efficiency.

Tosh

Phew, someone who knows what I'm on about. It just gives the engine a better chance at regulating the best temperature to run at especially if you run a turbo or even a 1242 as I've heard they run a bit hotter after being fitted.

I'm only going on the vast experience of Renault 5 GT Turbo tuners out there who are getting more than 300bhp from a 1.4 push-rod engine! They know there stuff and running a bit cooler is always a bonus when extracting more power.

There just isn't the wealth of knowledge with the FIRE engine as there is for the Renault or Ford units, so I'm trying new things based on other engines as all engines work on the same principle, and if I get results, which I do, I like to pass them on.

Aaron.

J333EVO said:

so I'm trying new things based on other engines as all engines work on the same principle, and if I get results, which I do, I like to pass them on.

Aaron.

Click to expand...

now that is a very good skill to have!!!!

how tricky was it to do? worth sourcing out a spare thermostate to play with?

p.s nice mug!

Aaron, you really seem to know your stuff.

My car has always run at 50-55 degrees ever since i have owned the car, only getting near 90 if stationary for a long time. as soon as you start moving its down to 55 again. On some journeys in cold weather the temperature guage will never even come onto the scale. But the car seems to work fine and i get good fuel economy from it. I always assumed nothing was wrong as when sitting in traffic the fan always used to cut in at 90 degrees. But as i understand it from this post the fan mechanism is not controlled by the thermostat, because yours switched on and off with no thermostat in.

My car sounds exactly like yours when you operated it without the thermostat, so i think i will definitely check mine out and try replacing it with another one. When you took your thermostat out did it take an age to show any reading on the temperature guage at all, like 10 minutes? thats what mine is like

Cheers

Phil

mase said:

now that is a very good skill to have!!!!

how tricky was it to do? worth sourcing out a spare thermostate to play with?

p.s nice mug!

Click to expand...

Yeah if you find your car is running that little bit hotter than you feel uncomfortable with, i.e. the fan clicking in every few mins, then yeah try source a 2ndhand thermostat and follow what I did. It should really take no longer than 30mins to do it, but I have came across 2 standard fit Fiat thermostats and the one made by Fiat themselves is easier to take apart and reassemble whereas the one in the pic which is still a Cinq thermostat is made by another company and to be honest a bit sturdier in its construction making it harder to do, but is achievable with a bit of force.

the mug came from the integrale London 2 Brighton run last year which was sponsored by Tanc Barret an integrale specialist and Blaupunkt who made 5 special Brighton head units as prises that are not available to the public.

phil_harry said:

My car has always run at 50-55 degrees ever since i have owned the car, only getting near 90 if stationary for a long time. as soon as you start moving its down to 55 again. On some journeys in cold weather the temperature guage will never even come onto the scale. But the car seems to work fine and i get good fuel economy from it. I always assumed nothing was wrong as when sitting in traffic the fan always used to cut in at 90 degrees. But as i understand it from this post the fan mechanism is not controlled by the thermostat, because yours switched on and off with no thermostat in.

My car sounds exactly like yours when you operated it without the thermostat, so i think i will definitely check mine out and try replacing it with another one. When you took your thermostat out did it take an age to show any reading on the temperature guage at all, like 10 minutes? thats what mine is like

Click to expand...

From what you describe it sounds like your thermostat may be stuck open as when I ran mine without it ran at the temperatures/times you quote, so may be worth investigating it. Its very simple to remove and replacements are available in Halfords and any other car factors, not unless you want to try and make your own 82degree one that is

HTH, Aaron.

!!Bump!! for all those tha missed it last time and are looking into cooling.

Aaron
How do you dismantle the thermostats without breaking them?
Cheers
Adrian

AIJ29 said:

Aaron
How do you dismantle the thermostats without breaking them?
Cheers
Adrian

Click to expand...

The donar thermo has to be broken, that is unaviodable as you need to cut through the leg of the section that holds it in palce. The on eoff the Cinq is made in such a way that you can dismantle it, if you look at the pic i've got of it there are 2 section sthat hold the thermo in place which can be flattened and twisted round to realease the inner bit, you will see what I mean if you look at you will see what i mean, its not that difficult just fiddly putting it back togther.

Once back together ensure it opens by boiling it in a pot and watching it open, wouldn't want it jammed shut!

Aaron.

hiya dude, i did my conversion job........damn hard work!! did they dismantling part but the original thermo i had was 87' and new one 82' but the 82' one had slightly wider body!! needed to drill open the top part that you say rotates to get it to open up but other than that.....all good!!

popped it in pan and even tho it says 82' it actually opened at bout 84' (well, it started moving at that!) is this right? and seemed smooth operation but had to change the springs around too, cus the original spring was too hard and it didnt open till 88' so popped in the spring it was meant to have and bobs ur uncle, opened at lower temp!!

just gotta pop her on and see if it makes a difference!!

Mintysport,

Where did you get your new bit thermo from? I have just bought one from Halfords, the prt number is HTK602. It opens at 82 and looks the same as aarrons, what was the part number of the one you bought?

Have you fitted this to your car?

Aaron, the std cinq thermo and housing in your photo looks like a halfords one?? It appears to be different to the two units ones I have, one from a 1.1 engine (Punto 55) and one from a 1.2 Engine (punto 60).

Thanks

David

peaster2k said:

Aaron, the std cinq thermo and housing in your photo looks like a halfords one?? It appears to be different to the two units ones I have, one from a 1.1 engine (Punto 55) and one from a 1.2 Engine (punto 60).

Thanks

David

Click to expand...

David,

I have came across 2 slighlty diff thermo's as fitted to the Cinq one the one in the pic made by a French company (and sold as Halfords own) who make the vast majority of thermo's in Europe as I know its them that make the low temp ones for teh R5GT and another which I presume is the Fiat one, they are both dismantable, if i remeber rightly the other one I had has little lugs which you can flatten with pliers and twist around to extract the thermo and is in fact easier to dismantle.

Stick a pic up if its vastly different.

Aaron.

Aaron,

Oh the thermo that Halfords sells (Part No# HTK629) fits a Cinq 1.1 Engine (didn't look at a Sei, sorry people), Punto 55 1.1 Engine and a Punto 60 Engine 1.2.

Anyways, the first two photos show the 82 Degree C Thermo I got from halfords (Part # HTK602)

The 3rd photo shows the Thermo Unit (without spring and clamp) that I removed from a Putno 55 1.1 Engine.

The 4th photo shows the Thermo Unit (again without spring and clamp) that I removed from a Punto 60 1.2 Engine.

When I took these apart I noticed that the push rods were different sizes, longer on the 1.1 Thermo (3rd photo) compared to the 1.2 Thermo (4th Photo). I gather though that I can fit either housing unit with the correct thermo unit to my cinq and it will work fine (at standard tempts though, opening at 87-88).

The thermo and housing I removed from a Punto 60 1.2 Engine had those little lugs you are refering to aarron, I found both of these easy to dismantle. If i get the chance I will punto them back together and take some photos of those as well.

HTH

David

P.S. The parts man in Halfords told me that I would break my ECU if I was to fit a different thermo that the one they/fiat recommended. I could of slapped him.

Once were on the subject of thermos. I had a look at mine and noticed a gasket, what are people doing on re-fitting to properly seal it?

Liam

bloomfieldliam said:

Once were on the subject of thermos. I had a look at mine and noticed a gasket, what are people doing on re-fitting to properly seal it?

Liam

Click to expand...

when i did the thermo on the NA cinq i just used the new paper gasket.sealed fine with no other sealent

Liam, Custard

Thats what I'm planning on doing when I fit mine. I have one left over from my headgasket set, but I also have some gasket paper, so I think I will make a few spares just incase.

HTH

David