Coolant temperature

[Jonny1*2]

I changed the coolant and thermostat the other day. Now the needle reaches middle sort of. The heaters are fine, and the level looks ok, but i've a suspicion that I might have an air pocket somewhere as the needle moves from middle to one bar below middle consistantly. Also, i've noticed that the lower rad hose seems to be cold after the car has warmed up. Is that normal?

If it is an air pocket, do I unscrew the bleed nut slightly to get rid of it, or is there something on the radiator itself?

 

[Dr HMS Derv Destroyer]

Get the engine running and undo the little bleed screw slightly, will flush any trapped air out. Can't remember if it's better to do when warm or cold tho

 

[MG cup]

Just the bleed nipple, have the car idling while doing it and having the lid off the header tank will have the same effect.

Get it up to temperature for both really. Iirc correctly your meant to leave the nipple out while filling up the system on the f4r.

 

[Jonny1*2]

Cheers gents

Just the bleed nipple, have the car idling while doing it and having the lid off the header tank will have the same effect.

Get it up to temperature for both really. Iirc correctly your meant to leave the nipple out while filling up the system on the f4r.

Yeah you fill it with the screw out until constant stream of coolant appears. Not sure where the air has come from mind :s

I've ran it for 20min tonight with the tank lid off and it looks like its streaming correctly. The needle flickered when I turned the heater on. I assume there was air trapped in the gear matrix too. Ill have another drive tomorrow and see if the problem has been resolved. Otherwise ill have to try this again.

 

[MG cup]

Yeah forgot to say have the heater's fully open on hot too.

 

[Jonny1*2]

Yeah forgot to say have the heater's fully open on hot too.

Can't remember if I did it on full heat, but if it persists ill make sure info next time

 

[Jonny1*2]

Right, so i've now run the car for ages, with the heater on max and used the demist setting on the climate control (AC was engaged). This hasn't sorted it, so I looked at the temp sensor and as soon as I touched the wiring on it, the car nearly stalled. So it's either a new sensor, or the loom to the sensor i'm guessing.

Presumably once I remove the sensor i'm going to get coolant everywhere, so before I remove it, how does it come? ie. with wiring?

 

[MicKPM]

Heater position has no effect on bleeding Renaults of this age as the heater matrix is an open unit (no thermostatic valves that open/close).

TBH bleeding these vehicles up is as simple as opening the bleed point on the stat and waiting for air free flow to appear so unless you're doing it on a massive slope its unlikely to be an actual air lock. Did you test the stat before fitting it as they can be faulty even from new... this year alone, from Renault, I've had two that didn't open and one that wouldn't close properly due to a faulty seal. I test them all now before they go into stock.

Presumably once I remove the sensor i'm going to get coolant everywhere, so before I remove it, how does it come? ie. with wiring?

Correct so don't remove it when the coolant is hot! You will get a new sensor only as the wiring is part of the main loom. Disconnect the plug and make sure the contacts are clean and tight.

Mick

 

[MG cup]

Heater position has no effect on bleeding Renaults of this age as the heater matrix is an open unit (no thermostatic valves that open/close).Mick

What controls hot and cold then on heaters? Changing the airflow around the airbox to avoid the matrix?

 

[MicKPM]

Yep, its a control flap that diverts air around the matrix heat exchanger rather than thru it.

 

[Jonny1*2]

Don't say that Mick never thought to check it.

The stalling issue is irrelevant FYI. Some coolant leaked into the tps wiring.lol.

If its moving up and down slowly from middle to 1 bar below would that suggest the stat is knackered?

 

[MicKPM]

If its going from the "normal" mid point to slightly low then it would make a poor sealing/stuck open stat a real possibility yes.

It could also be an electrical fault with the vehicle to. Does it do this silly needle dance when the engine is at temp but sat idling or is it only when you drive it and have air flow thru the radiator?

 

[MG cup]

Sorry to clutter ops thread.

For filling up Mick, take the bleed screw out while filling up until coolant comes out of there then refit and top up fully. Start car, get up to temp with the header tank cap off then jobs a good ene.

All these French boxes seem to have a procedure all to their own for bleeding

And don't the clio's have a big temperature spread possible while the gauge will still be central?

 

[Jonny1*2]

If its going from the "normal" mid point to slightly low then it would make a poor sealing/stuck open stat a real possibility yes.

It could also be an electrical fault with the vehicle to. Does it do this silly needle dance when the engine is at temp but sat idling or is it only when you drive it and have air flow thru the radiator?

It doesn't do it while idling unless the rad fan is on, and obviously when driving.

 

[Jonny1*2]

I forgot to add, when the fan is on, no coolant seems to be flowing into the reservoir.

 

[Jonny1*2]

Anyone

 

[sam_clio182]

Thread bump but I'm having this problem the now recently had thermostat changed few weeks ago now all of a sudden cars going too temp fine the needle starts going bonkers after driving for 5+ minutes dropping slightly and back too have way several times then going from hafe way too bottom over and over again think it could be the coolant temp sensor?

 

[MicKPM]

I've got this car coming in shortly so I'm sure Jonny will report back soon.

As for yours, are you sure its been bled correctly? A faulty CTS won't normally cause the need to jump about like that. Live data will confirm/deny this.

 

[jesus]

Did you fit a genuine sensor from Renault? Don't use GSF/ECP s**t. Only makes things worse.

 

[sam_clio182]

The car broke down with heating issues so phoned the AA and used my cover as was away from home at the time they towed me too nearest garage and thermostat was identified as the problem was jammed shut so the garage replaced it put new coolant in and bleed it all and car worked fine after then until now and that was few weeks ago then this happened last night the sensor wasn't replaced at the time tho that's why thought it could of been that going too look at it today see if the sensor needs cleaned of if its to do with the wiring searched a few threads on here and seem that sensor or wiring could be the problem too me was going too buy one from Renparts or do you suggest using a genuine Renault one if I can't sort it today?

 

[jesus]

No, don't use a used one or an aftermarket one. Get one from Renault Wolverhampton on here/your local Renault dealer.

I used one from GSF which seemed decent enough. Made the problem worse... a genuine fixed it and it's been fine ever since.

 

[sam_clio182]

Ok then well il have a look today see what like then probably order one from Renault then but am from Scotland so Wolverhampton bit far away from me lol or would they send it up?

 

[jesus]

Yeah they do postage. Good prices too

 

[sam_clio182]

It's going back too the garage that fixed it in first place and getting sorted free of charge it's the thermostat that's faulty it's jammed open

 

[jesus]

They diagnosed it as that in the first place didn't they? Why wouldn't they change it in the first place?

 

[sam_clio182]

It was a few weeks ago and it was jammed open so replaced it but this time it's jammed shut and they didn't use a genuine renault one I asked when phoned today so this time it's going back and getting a proper one and new sensor also genuine fingers crossed will sort the problem

 

[-Craigo]

Sorry to bump but do you have an update on your cars status? Mine is going from nothing, heating up to middle bar then dropping 2 bars and slowly rising and falling between the two. Also ive got no heating, and a small coolant puddle on the top of my gearbox lol. Thermostat!

Is there a way to if something is wrong while driving the first few miles before the car actually dieing if theoretically, I bodged the job or I bought a duff thermostat? Got my new one arriving this week.

 

[jesus]

Sorry to bump but do you have an update on your cars status? Mine is going from nothing, heating up to middle bar then dropping 2 bars and slowly rising and falling between the two. Also ive got no heating, and a small coolant puddle on the top of my gearbox lol. Thermostat!

Is there a way to if something is wrong while driving the first few miles before the car actually dieing if theoretically, I bodged the job or I bought a duff thermostat? Got my new one arriving this week.

I didn't understand the question but always buy genuine.

 

[-Craigo]

Sorry jesus, in a nut shell.. basically after replacing, is the only way to tell you've got a duff thermostat by the temp gauge.. obviously at that point it might be too late if its gone high.

Oh and another question, apologies! Ive not got a hose fit to my house, would a bucket surfice to flush the radiator and ro fkush the engine would yiu recommend after ive replaced the stat, to fill it all back up as normal but just with water, run for 25mins, empty and repear once more.. then putting in the coolant? Without a hose I just want to make sure its sufficiently cleaned because I went to the place I get my services done and found out they used an OAT based coolant last time, gutted. Although whats in it now is almost fully diluted lol. Im moving back to renault's own.

I was also just curiis as to the chap aboves out come, see if he managed to get everything sorted and how

Cheers for the reply m8, few n far between these days lol.

 

[-Craigo]

Finally had time to change my thermostat! The rubber seal in several places had completely came away! Ill get a pic of it up shortly. The garage I got it from, I assume it was him, obviously knew it was f**ked and has sealed it with a ailicone sealant lol. Obv where the leak and pressure loss was coming from.

Engine temp is now spot on. Although still no heat from the blowers. Im thinking there is air in the system so im waiting for it all to cool down before I attempt to bleed it because once every 10mins or so the temp needle will drops only half a bar then goes straight back to normal. Am I correct in thinking this is air? I noticed the coolant has gone down in the expansion tank but its too hot atm to release any nipples or the top!

What would be the best way to bleed it, leave the expansion bottle lid ON and bleed it through the thermostat OR take the top off and then bleed it? Or perhaps release air through the screw nipple on top of the large pipe?

Honestly the old thermo is attrocious cant believe its actually ran for a year while ive had it.

 

[-Craigo]

This is the state of the old thermo...

https://db.tt/fUDoVc06