Coolant Problems - High Temp/Rises Quickly

[f0xy]

In two years with F4R's Ive NEVER had a problem with air locks or the engine overheating, until now.

At the start of the month I had a few weird issues at Oulton Park, where the temp gauge would rise up past the max marking on the gauge, then come back down again, and repeat. I wasn't sure why it was happening as the car had been fine since replacing the clutch and re-bleeding the whole system to the book...

After the Oulton Park day I never had a problem until a few weeks ago, where the needle would go up very high under normal driving conditions very quickly, I.e. within 5-10 minutes of driving. Like the thermostat wasn't opening and it was getting hot quickly.

So I bought a new thermostat, and fitted a different (Known 100% working) coolant temp sensor. I flushed the whole lot with a hosepipe, including the radiator, then re-filled the coolant system. I undid the bleed screw on the side of the housing until there was a constant flow of fluid, numerous times, whilst topping up the reservoir. Ran the car upto temperature until the thermostat opened and the gauge stayed normal, just on halfway which is previously always was...

The car seemed OK to begin with for a day or two, but then it went back to its old ways - the needle going sky high, sometimes off the gauge entirely! For example a 10 minute drive over 4-5 miles would see the needle off the gauge, not even enough time for the thermostat to open! Ive had this on other cars where there has been an air lock near the temp sensor, but I even re-bled the system from scratch again and kept the same problems.

I wondered if the thermostat might be dodgy and Ive got a dud new one, but I removed it and checked it in a bowl of boiling water - it was perfect. I even tested the old one, which was fine too - so buying the new thermostat was pointless really..

After testing it I re-did the whole coolant process again, and it was OK when getting it up to temperature right after re-filling - the needle sat happily in the middle for nearly 35 minutes at various RPMs. That evening after driving it the same problems were back again - and Ive no idea how!

Anyone had anything like this before? As its starting to p*ss me off now...

 

[sideways danny]

Coops F7P turbo is doing the exact same thing IIRC

It's radiator related IMO

 

[f0xy]

How very weird, I have a spare so I might try swapping it. What can go wrong with a radiator apart from leaks though?

Should have mentioned in the first post the coolant level is remaining consistent too, never drops/looses any..

 

[sideways danny]

I had to change the rad on a 12. 8v mk1 a while ago that was doing pretty similar things. There was ZERO flow between the outlets.

If you thing what the insides of a rad is like, it's just a series of very small bore gallaries. Doesn't take a lot of silt/radweld or other crap to cause a blockage

 

[f0xy]

Yeah, interesting.

When I had the hose pipe in the top hole it was gushing out of the bottom, but it could be anywhere in the radiator I guess. When the coolant temp goes right up the radiator is extremely hot, never as it used to be I dont think, hmmmm.

 

[sideways danny]

is the rad kicking in ok?

 

[mat-nos]

rads can corrode and block internally?? does the coolant tank seem overly hot when the temp goes up and did lots of s**t come out the rad when you flushed it??
if a different rad does not solve it, could be a sender/wiring/sensor fault??

 

[Gray]

Mine was doing the exact same thing at the start of our Euro trip (queuing to get on the ferry LOL!) shot up to max temp in 5mins and would not go down, I had a massive build up of pressure in the system, opened the bleed screw and had a lot of air spit out then a HUGE woosh of air, then coolant.


Was all ok for a few hours then did it again... and again... and again... going up and down constantly?! Then just went back to normal after 2 days :S

I put guessed a dodgy thermostat, never bothered to investigate when I got home.. but that doesnt seem to be your issue as youve swapped it over?

Not really helped you but it does seem a strange one!

How old is the radiator, ever used any rad weld (or something that cold cause blockages?)

 

[f0xy]

is the rad kicking in ok?

Rad Fan? Yeah kicks in as per normal, gauge on the dash will go down, then go back up again once its gone off. Thing is too, if you are driving and it goes to the top of the gauge, say after 30 seconds it will slowly drop again to around 3/4 then just rise after another minute or so......which repeats over and over

rads can corrode and block internally?? does the coolant tank seem overly hot when the temp goes up and did lots of s**t come out the rad when you flushed it??
if a different rad does not solve it, could be a sender/wiring/sensor fault??

Was all fine when being flushed out, the rad is only about 10k old. Coolant tank does not even get hot within the first 5-10 mins, maybe because the thermostat hasn't opened yet? After some more driving the fluid gets hot in there too, and if you give it some revs you see coolant coming back into the reservoir via the small pipe.

 

[f0xy]

Mine was doing the exact same thing at the start of our Euro trip (queuing to get on the ferry LOL!) shot up to max temp in 5mins and would not go down, I had a massive build up of pressure in the system, opened the bleed screw and had a lot of air spit out then a HUGE woosh of air, then coolant.


Was all ok for a few hours then did it again... and again... and again... going up and down constantly?! Then just went back to normal after 2 days :S

I put guessed a dodgy thermostat, never bothered to investigate when I got home.. but that doesnt seem to be your issue as youve swapped it over?

Not really helped you but it does seem a strange one!

How old is the radiator, ever used any rad weld (or something that cold cause blockages?)

Sounds exactly the same... Yeah new thermostat and ive tested both new and old in boiling water - they both open fine!

Radiator about 10k if that, and never used anything other than coolant/water in it...

 

[sideways danny]

right, becoming less convinced it's the rad now tbh

I actually had a bit of an overheating issue my self for a few days before my car was mapped. I was using a little too much ignition r****d to hold the idle down so the cylinder temperatures were getting pretty high. now it's unlikely to be that on the stock ECU, but it could still be heat related, maybe fuel pressure has dropped or the pump is failing???

 

[Soot1e]

It's gotta be the water pump now , after all the other things youv'e done.

 

[DAVEE]

sounds like head gasket if a thermostat hasn't sorted it .

 

[sideways danny]

if it was water pump (not saying it 100% isn't) then the rad wouldn't get hot as the water wouldn't be pushed around the engine

 

[Soot1e]

sounds like head gasket if a thermostat hasn't sorted it .

he wouldhave other problems if it was the gasket

 

[f0xy]

right, becoming less convinced it's the rad now tbh

I actually had a bit of an overheating issue my self for a few days before my car was mapped. I was using a little too much ignition r****d to hold the idle down so the cylinder temperatures were getting pretty high. now it's unlikely to be that on the stock ECU, but it could still be heat related, maybe fuel pressure has dropped or the pump is failing???

Yeah, just standard ECU with one of the RSTuner maps on (been like that since April09 ish)...

Although its funny you should mention the fuel pump (before I carry on its a 60k 172 Ph1 Pump inside a Mk1 housing) - I had issues with it at Oulton for the first time ever, which was the same day this coolant problem came about. Under hard cornering with 1/4 of a tank it would cut out and miss fire quite badly, then come back on a second later, like lack of fuel or fuel surge. After I filled it up again it was fine, but that might not be related (Never had a problem at Rockingham, Mallory or Cadwell with low fuel earlier in the year, on the same tyres etc.)

Since then ive had the odd problem starting, which I guess could be the pump, as its like the pump sometimes does not run when cranking (Although most of the time it will be fine). Most recently I did a 260mile run (all motorway) and the coolant never went above half, even when stationary (as it would usually rise quickly) - but the odd thing is it only used 22-23l of fuel, equates to about 50mpg which did suprise me as it usually only does low 40's. If the fuel pressure was lower could it have had some sort of effect on that, using less fuel?

None of that may be related at all though! Ive got a spare valver pump here. Il fit it shortly and see if there is any difference...

 

[f0xy]

It's gotta be the water pump now , after all the other things youv'e done.

Water pumps about 10k old, replaced when I had the engine out last... Although, there isnt much to break on them bar a bearing is there? Its just a shaft with a pulley on one end and fins on the other?

sounds like head gasket if a thermostat hasn't sorted it .

he wouldhave other problems if it was the gasket

Headgasket was brand new with a skimmed head about 10k ago! Unless its a dud...

 

[sideways danny]

get that fuel pump changed i recon. that sounds like it's flowing hardly anything.

 

[Soot1e]

As the thermostat has been proved to open ok then then hot water would leave the engine block as the pressure builds in the waterways of the block and push hot water into the rad, ie the old theory that hot water rises or this case goes sideways (pardon the pun Danny)

 

[Soot1e]

get that fuel pump changed i recon. that sounds like it's flowing hardly anything.

Why the fuel pump? Surely that is unrelated to an overheating prob.

 

[f0xy]

get that fuel pump changed i recon. that sounds like it's flowing hardly anything.

Il give it a try...wouldnt it affect performance with a lower pressure though?

As the thermostat has been proved to open ok then then hot water would leave the engine block as the pressure builds in the waterways of the block and push hot water into the rad, ie the old theory that hot water rises or this case goes sideways (pardon the pun Danny)

Im unsure if its a flow problem as this particular engine has been fine since it was first put in, its just all of a sudden happened without changing anything. Unless somethings broken off or a lot of s*it has collected somewhere inside the block.....

Why the fuel pump? Surely that is unrelated to an overheating prob.

Lack of fuel could affect the map/ignition timing I think Danny was trying to say, if its ignighting at the wrong time for the fuel/air the piston would get a hotspot?

 

[Soot1e]

But not as hot as you describe. Haven't see a clio water pump yet but if they have a plastic impeller they are prone to damage or falling of the spindle. Looking at my pump it seems it will easily unbolt in 15 mins. My other thought is the cooling pipework is not connected to the right parts of the engine, I know it's difficult to get wrong but i'm not familiar with your model.

 

[f0xy]

My coolant system is even simpler than most, as there is no heater matrix... Thing is too, its ran fine setup like this for years.

Just drove it and the coolant temp seems to rise very quickly if you give it any sort of heavy throttle/load, then itl go back down again if I cruise it at 30mph in 5th..

 

[Gray]

My coolant system is even simpler than most, as there is no heater matrix... Thing is too, its ran fine setup like this for years.

Just drove it and the coolant temp seems to rise very quickly if you give it any sort of heavy throttle/load, then itl go back down again if I cruise it at 30mph in 5th..

Just what mine was like.. I've also heard my Clio has a fuelling problem with the new owner, he thinks in injector is on its way out?

 

[Gray]

LOL.... Rollin' down towards Furka pass

 

[f0xy]

Exactly like that^, goes even higher sometimes, off the gauge!

Im going to swap the pump tomorrow and see if it makes any difference...

 

[Gray]

mine would fluctuate from max, off the gauge, straight down to min, up to the middle.... all with in 1 - 2 minutes!

 

[Djw John]

Worth chucking a new coolant temp sensor in? For the 2 minutes it'll take I dont see why not

 

[f0xy]

Already have done mate... Tried one from a 172 that works fine and it seemed to make no difference to the reading

 

[Ali]

Sounds like the radiator to me...Same issue with the other halfs Bini!

 

[Andyrg@ ClioTurbo]

It can only be a few things causing this Jord.

1) False Readings by the ECU
2) Over heating due to Head Gasket - There very very strong on these cars, But i hope you stuck a decent one on
3) Air Lock - Your sure its sorted so this isnt a option
4) Stat - You have changed this
5) Sensor - You have changed this

I dont think it will be the fuel pump cauing this mate, The car would be driving like a pile of s**t if it wasnt pumping enough fuel into the system, look at ours at Rockingham it wouldnt even start! I hope it is tho, and u reslove it

 

[f0xy]

Sensor has two outputs, one goes to ECU and one goes directly to clocks, so that would point to the coolant temp sensor but ive swapped it... ECU does not provide the info for the clocks...

Headgasket was brand new around 10k ago, but it could have been a bad one and only just started having problems now... who knows!

Yeah bled it plenty of times and im quite confident there is no air in there - every time I re-bleed via the bleed screw its just all fluid straight away, no air comes out...

Yeah changed stat/sensor, its just dodgy as f*ck!

 

[Gray]

I am 99% sure mine was airlock related, soon as after I bled it a few times the issue never came back

 

[f0xy]

Yeah...but its come back for the new owner did you say?

Thing is though, if it is an air lock and I keep bleeding it, how is it coming back?

 

[Gray]

nah... the new owner is/was having fuelling problems, nothing overheating wise since I bled it a few times

 

[Andyrg@ ClioTurbo]

jord, dump the entire system, remove bleed nipple, fit the expanision bottle once its got water in blow through it, untill you have constant water coming out, I had a overheeting issue not as bad but a little one with a laguna 1.8 16v. Resolved the problem.


Do a sniff test, ill send my Snap on one down too you if you want too confirm its not the head gasket

 

[S76Pilot]

I know this is a long shot but is it worth trying? I'm new to the whole clio thing but had a ford fiesta that had exactly same problem. I spent ages flushing, changing pumps, radiators, thermostats etc, and it turned out to be the heater solenoid valve beside the bulkhead. Now as I know very little about clios yet I dont know how the heater system works, but if there is a heater control valve in the water side, (kind of a 4-way electrically operated thing) it might be worth swapping it with someone elses to try.

 

[f0xy]

They dont have anything like that, but I know what you mean from seeing them on fiestas. I have no heaters anyway, its just plumbed up as engine/rad :dapprove:

 

[S76Pilot]

I'd put money on it being a head gaslet going then. Take a sniff of your coolant.

 

[mark123]

Have you felt the centre of the rad when it's over heating, all the way down? If the rad was blocked you'd expect some bits to still be cold compared to the sides of the rad.