little bram

Its something ive ever thought about so I don't really know the answer. The reason a asking is because my car runs hot all the time. There's nothing wrong with my coolant system the only thing I can think of doing is trying to fit a bigger rad. The car runs at 80 and 90c on motorways but in traffic or just letting the car idle it runs in the 100's to about 110c then try's to cool its self to about 107.
Am running waterless coolant so it doesn't boil or have any pressure in the system at all so you can let the car idle at this temp with the cap off.
So that brings me to my question what's your opinion

thanks if you can help

lee

Mondego

So, if you wern't running waterless coolant, then the car would boil itself?

Maybe its not that hot at all, and the guage is fcuked. But you can probably notice mega heat radiating from the engine and/or you're maybe using a thermometer?

little bram

Yeah mate it would boil over if it had water in and it is running that hot because ive got my laptop plugged in so can see how hot its getting. the car run's fine just very hot

fraser9764

iTrader: (3)

110degC doesnt mean it would boil over. The coolant system is pressurised when running normally with the cap on. The boiling point of water increases with pressure.
Of course if you take the cap off it will boil over but you shouldn't be taking the cap off with the engine hot.
Sounds perfectly normal to me, except you might want to replace the fan switch as it is a bit high. You want the coolant to be hot for thermal efficiency. Most new cars will run higher coolant pressures and over 100degC normally, despite what the gauge tells you.
Replace fan switch and refill with normal coolant then forget about it.

Chopshop85

iTrader: (4)

timing?

little bram

I change to waterless coolant because with it running that hot the pressure in the system was high and last year at ford fair while waiting in traffic to get in I thought my bottle was going to blow up. Now with this waterless in there's no pressure even at 110c I can take the cap off and there's nothing. just wounding about if it will be ok running that hot.
Also what you said about water boiling point under pressure I knew about that I read it one of stu's articles.

little bram

Yeah mate I did think about the ignition timing but its been mapped so should be ok

little bram

Just to add am running aftermarket management so can put the fans in and out with the ecu.

jamie's

has it defo got the right temp temp sender in it?
as the wrong colour code switch will make the gauge read wrong
(you prob already know that, but start with the basics eh)

little bram

I don't know about that to be honest mate ave got a cosworth cts in but can't see how it can be reading wrong.

jamie's

what ecu you running? is it haltech?

Mondego

Really, I didn't know this.

I have heard of high performance motors running WAY higher coolant temps (maybe the OP's car too, if there is no problem) but didn't realise "most" new cars too. Mine certainly doesn't run anywhere near these temps, although it's not really new ('58 Mondeo), and it's a diesel!

SiZT

For fuel efficiency yes, for maximum power no

little bram

Yeah mate running haltech. I've also herd that new cars run hight temps so am going to have a look at work if I get the chance.

stevieturbo

The fact it's fine when driving more than likely points to lack of radiator, fan, airflow etc when slow moving.

There can be many issues.

What radiator do you have and is it in good order ?
Is it installed properly so no frontal air can just pass around it, instead of through it.
What fan are you using, and is it installed correctly ? And does it cover enough of the actual core ?

What thermostat ? What temp are you turning the fans on/off at ?

Brendan

iTrader: (1)

Turbo charged CVH's do tend to run hot (especially in a confined space with limited air flow). To stop this (and I might have gone too far) I have done the following.

make sure my radiator clean from sludge!

Fit a rad for the turbo plumbed like the heater matrix so it is always on. turbo's run hot, so this dumps more heat rather than the engine's rad having to do this too!

Bigger inter-cooler.

Hot hone the bore.

Water Cooled exhaust valve guides. This really moves the heat out of the head very effectively.

I am thinking about waterless coolant - purely as it will not corrode the block at all! This has the benefit of never freezing too and will not boil till about 180°c so will not pressurize the coolant system (therefore putting pipes etc under less stress.

not 100% sure about its efficiency relative to water about moving heat but it is nearly as good.

It also lasts the life of the engine - but is expensive!

http://www.evanscoolants.co.uk/


Remember more power requires faster removal of heat away from the engine!

scoooby slayer

iTrader: (4)

if you've got an 88d stat in it and your seeing 110d in traffic your rad is cooling sufficiently stationary.

my Chrysler was overheating and boiling water out real bad, it seems ok now but I have fitted a 16" kenlowe and an 8" all on suck to keep it cool.

my opinion of putting liquid in that doesn't boil is not a cure it is just masking a problem that needs fixing.

St3V3_C

So the fans don't come on until 110c?

If so, I would say that's the problem - bring that down a bit.

little bram

The coolant system is ok flows ok and no blocks in it, ive got a pro alloy rad and 2 fans on it that over hang the rad at both sides. I don't run a thermostat because with how hot it runs it will be open all the time and restrict flow, I had one in but wasn't making a diffrent's. I also got a new thermostat housing because in every housing ave seen have there needle that gets the air locks out are missing. Ave got the fans comming in at 100c and are ment to go out at 95c but when idling never gets back down to 95c just stays in 100's

Brendan

iTrader: (1)

what is it like on a gentle run say 60ish for a while? does it cool down?

little bram

Yeah mate it starts to drop. I haven't had the computer on and been for a long run but when I did have it on it drop in to the 90's.
Like ave said it run fine and now ave put the waterless coolant in there's no pressure and the coolant isn't boiling just am unsure if everything will be ok with running as hot as it does.

Mike Rainbird

iTrader: (3)

This is your problem.

Change the trigger point to 93°C for the fans to come in and your cooling problem will go away. The issue is that you're letting it climb too high in the first place.

The Escort Cosworth is the same, it has two-speed fans as standard and the second high speed stage doesn't come on until 100°C, so in traffic or on track the cars always run really hot. Switch to the single speed Sierra switch (which comes on full speed at 93°C) and the problem disappears.....

fraser9764

iTrader: (3)

I'm a little confused, so your fans are set to come in at 100 and off at 95, but when sat in traffic the temperature will increase past 100 (turning the fans on) and continue increasing to 110ish until it starts to drop but only down to 107 where it will sit until (still with the fans running) until you start moving and put some airflow through the radiator, The fans will eventuallly turn off when the temp reaches 95?

If the above is correct then your fans are inadequate..

This doesn't sound good. Can you post a picture?

little bram

Ok Il try putting them in earlier and see if it works. So on a escort cosworth its designed to run at 100c?

stevieturbo

Sounds like a very bad setup. Put a thermostat back in, they arent there just for laughs. Running no stat will be a backward step as it will affect water flow through the engine.

Fix the fans so they come on at a sensible temperature. 100degC is just daft.

Post a pic of the fan setup, and radiator in general.

scoooby slayer

iTrader: (4)

I tried my chevy with no stat and it overheated, it needed the restriction of flow for the system to work correctly.

little bram

Yeah mate seem to me like the fans and rad aren't up to the job but really they should be.
1dc18f2c-dc1c-48f1-ba6e-510d263667e5_zps59a33fbf.jpg?t=1372695053

stevieturbo

Are the fans mounted tight to the core, so no air can escape ?

Are the fans fitted correctly. ie they are installed as pushers, so are they pushers and are the wired correctly to blow air through the rad ?

And seal off around the sides so hot air cannot re-circulate back in front of the rad.

But they look to be a decent size and cover a good amount of the core, so should be adequate.
What make are they ?

little bram

OK mate I didn't say it was in for a laugh and if you read what I wrote I had a thermostat in and it was the same so am trying different things to make it run better/cooler. Also the fans haven't always been set to come at 100c but close to it.
Mike has just said the escort cosworth second switch doesn't come in till 100c as well.

stevieturbo

Second fan maybe, but the primary fan will come on cooler.

If anything, try a colder stat, but running no stat is never a good idea.

little bram

They are kenlowe fans and the frame of the fans are flush with the core of the rad so the fan blades are overhanging the sides of the rad. yeah they are wired up so they are going the right way. there is an intercooler in front of them fans as well.

little bram

My thought on taking it out was that the coolant would flow faster so less time coolant was in the engine boiling up. But I do know what you mean about slowing it down so that the coolant is in the rad for longer so has more time to cool.

fraser9764

iTrader: (3)

The Bit overhanging is a problem, there is absolutely no seal around that side, so most of the air displaced by the fans will take the easiest route out of that gap and away from the radiator. you would be much better off with two slightly smaller fans sealed to the front of the rad.

little bram

The frame of the fan is flush with the core so just the blades over hanging mate so really should be ok+ the blades don't actually over hang the sides of the rad.

stevieturbo

More flow is a good thing, but removing the stat doesnt just do that. It can change how the water flows.

If you want to run no stat, remove the centre section of the stat and run it like that.

If coolant flows slower, it also means it is stuck in the block longer getting heated. Flow is good.

Mike Rainbird

iTrader: (3)

Yes, but they suffer the same issues you mention by running like this (I believe it is an emission target related set up - running the engine hot gives better emissions). Switch to the original Sierra arrangement and Bob is you're Mother's brother - sorted.

Seeing you have the option of changing the trigger point with relative ease, it would make sense to do this immediately and see what effect it has. Set them to come on at 93 and switch off at 90.

I can't see how you are surprised that the temps are running at a constant 100°C + with no air through-flow and the fans being triggered to come on so late .