Technical What coolant temps would you consider safe?

[randomizered]

I'm seeing temps of up to 98 degrees when motorway cruising at speed. These are sustatined temps that drop down if you ease off a bit.

How many people think these temps are still ok. It certainly causing no harm at the moment, but i think in the long run it may not be that good for the engine.

It's not a faulty cooling circuit. The engine is only about 15K, theres a brand new genuine MM radiator, all bled, new pre-mixed antifreeze.

A lower temp thermo is a no go, as it will be fully open when im seeing these temps, and the loop temp doesn't drop at all.


If these are a bit high, what route is recommended by others?

Don't fancy retrofitting a bigger non cento rad, so i se the choices are;

Oil cooler with thremo plate
Combined coolant/oil cooler

Any comments?

Kristian

 

[arc]

Re: What coolant emps would you consider safe?

anything over 90 at cruising speeds is imo too much. i dont pay much attention to my coolant temp gauge, more so to the oil temp gauge.

What is the bumper like at the front of your car, is your wheel arch vented? any scope for opening it all up for more airflow?

 

[randomizered]

Re: What coolant emps would you consider safe?

Standard mpi/mk2 bumper, wheel arch is vented. Can't see any way of getting much more air in there.

I fancy an oil temp gauge, but can't do it at the moment.

KRistian

 

[fingers99]

Re: What coolant emps would you consider safe?

Too high. Especially when you consider it's bloody cold out there. What speed are you cruising at?

Cheap solution, duct the radiator to the front bumper. That blown nylon (not polystyrene) stuff they use for packaging is ideal -- there will be some in a skip near you. Save the world and all that.

The air will probably womble it's way out somewhere: blanking off the other useless holes on the front may help.

It may be running a touch lean.

Of the oil cooling options, the air/oil heat exchanger is far kinder to the engine, but as you're running into overheating problems with the standard rad, it probably doesn't make any sense to make it cool the oil as well.

 

[randomizered]

Re: What coolant emps would you consider safe?

AFR 13.5-14 and the speed is similar to 08 -> 58 mph if you know what i mean.

May drop Emma or Aaron a PM if they are not viewing this. Would be interesting to see what theirs does!


Kristian

 

[fingers99]

Re: What coolant emps would you consider safe?

Yeah, PM the EVO crew!

You're probably loosing performance running at those temps, too.

Ducting really is worthwhile and should cost you next to nothing.

 

[jamie86]

Re: What coolant emps would you consider safe?

There's doesn't run that hot.. although that's all i can help with

 

[J333EVO]

Re: What coolant emps would you consider safe?

Just read this, even on long drives for a few hours in hot weather at sustained high speeds we get no more than 80ish on water and 100ish on oil if really pressing on through gears etc, otherwise on say a constant run at high speed oil temps drop off to about same as water, maybe bit higher 90ish.

If you are getting those sort of temperatures then your fan circuit will be constantly open which at speed is not meant to happen as there should be more than enough air passing through it to keep it effectively below the temps the fan circuit closes, not opens as if it was that way it could open in slow traffic and then stay open on the move, so should be below closed temp if you follow.

 

[arseofbox]

Re: What coolant emps would you consider safe?

Hmmm, on the subject of cooling, whats stopping running an fuel/oil heat exchanger?

Its common practice on aircraft, but Jet A-1 is normally nowhere as near its flashpoint as petrol is in normal operation.

But that would solve heat issues and fuel icing too

 

[arc]

Re: What coolant emps would you consider safe?

tom... step out of work mode!

carb icing is only an issue where the fuel is injected really, and with MPI its so close to the port it is fine. dumping engine heat into the fuel would help lower the engine temp (good times), but also increase the fuel temperature (bad times)

 

[fingers99]

Re: What coolant emps would you consider safe?

I've seen pics of some turbo cars with fuel coolers. But providing the fuel company puts the right chemicals in the petrol, icing shouldn't be a problem in any car, let alone fuel injected ones.

Of course, the other thing is that petrol evaporates a fair bit at ambient, let alone when heated.

 

[levemircento]

Re: What coolant emps would you consider safe?

just for info really.

My cinq never goes over 90, the fan comes on at about 85 which keeps a lid on the maximum of 90, motorway running it would normally run at about 60-70 on the gauge, sometimes less on a downhill bit!! temp never really goes up much in the summer, or uphill.

 

[cc1]

Re: What coolant emps would you consider safe?

What guage are you using to show the temp?

 

[randomizered]

It's the standard OEM panda 200hp sender, mounted in the normal position, just before the thermostat. I am reading the values directly from the megasquirt.

I calibrated it and tested values at -10, 5, and 100 degrees.

I have another temperature gauge and sender, a raid hp gauge. I may refit it just to confirm I calibrated the sensor correctly. I think i did though

If i haven't calibrated it right, i'll just swap it for the cinq/sei WT_05 as i have a datasheet for that.

Kristian

 

[cc1]

It was the calibration issue that I was thinking about.

 

[randomizered]

Yep, I'll double check tomo, comparing the other gauge. I'm sure i did it accuratly enough. Sadly there wasn't a datasheet for that sender.

I'll update soon

Kristian

//ps. thanks to whichever mod corrected my thread title

 

[gazzaman2k]

ill have a look at mine tomorrow see what temp mine runs at? it has no thermostat and just comes on when the rad switch clicks on

 

[prompon]

Guys, I have been reading this thread so quite some time now and I have a question to ask. It has nothing to do with the problem which started the thread but, I live in Malta, and the temperature's are quite high here. My question is, is it normal for the gauge to be over 90 degress? When it goes above 90 degress it stays on the other bar on top of it and does not go higher... And another thing, when the engine is on idle the fan starts and lasts for 10 seconds max but when I switch it off it stays for 4 minutes to 5 minutes non-stop working. Is it ok?!

Thanks alot for your patience.

David.

 

[fingers99]

The when you switch off stuff is normal: you get a fair bit of heat soak with the water pump not running which causes the fan to run. It doesn't do a lot of good, though........

Otherwise, the temperature is probably a bit high, but in Malta, I guess that's to be expected. It's no coincidence that low temperature thermostats are an over the counter item in places like Greece.