General Engine Temperatures my views

[guyinbelfast]

Hi, been reading some of the postings in relation to engine temperatures and i think people need to remember that a petrol engine is at its most efficient at high temperatures. The temps on the guages (and there are probably differences between gauges on different cars) do not mean that your coolant is boiling or anything like that unless it goes well into the red. The system is pressurised and will only start to 'boil' about 130 degrees Celcius or thereabouts. In a pressurised system the water is not boiling at 100 C, 110 C or anythign up to about 130 C. While 130 is high, the normal (optimum) operating range should be between 90 and 110 degrees C. The system is pressurised to allow the water to boil at a high temperature - it has been designed like that by FIAT.

A car that is running with a low normal operating temperature will not be particularly efficient on fuel, plus the oil never gets a chance to thin and will be like sludge chucking round the engine putting stress on internal components. A normal operating temperature below 70 C will not be thinning the oil very well. Image if all you ever did was cold starts - thats what an excessively cool running engine will be like, stressing away at the insides of your engine.

So a too hot engine is bad, so is a too cool one.
teach physics at university

 

[randomizered]

You are right, too cool or too high and you've got problems. May cento's have no guage thought, so for those you'll never know I'd rather know its a bit too cool, rather than too hot though

Kristian

 

[GhostWKD]

i like my coolant cool, as i know my oil is boiling

 

[J333EVO]

The system on a Cinq is pressurised but not by much, something like 0.8bar, whereas later Seicentos are pressurised to 1.4bar, have vented wheel arch liners, and on MPi models a bigger rad, more blades on water pump impeller, I think as the model evolved Fiat knew themselves it ran to hot, one of the reasons so many suffer overheating and head gasket failure, tho this can also be credited to lack of servicing i.e changing coolant every two years, new rad every 5 or so once efficiency has dropped as its been silted up etc. The Cinq system if it were to run at 110degrees would have a fan cut in at roughly 112 and switch off at 108, but it doesn't the fan cuts in at I think 93 off 88 (could be a few degrees out but not by much as mine is lower just can't remember by how much now) which is a sure indication of where Fiat wanted the engine to run, 90ish.

The oil on these cars will run way hotter than the water left unchecked, (very good 2 page article in this months Practical Performance Car mag on it) and I have seen oil anything from 20-40 degrees hotter than the water on a Cinq. The oil should run between 80-110 to get its maximum performance.

Alex for your benefit, round Castle Combe on Sat in Jamie's Cinq which has no cooler like you we saw 120+degrees on the water after 4 laps, i shudder to think what the oil was at

 

[GhostWKD]

i know i'm madly trying to sort this oil cooler, thinking remote filter setup at the moment, just need to price stuff up etc

 

[J333EVO]

i know i'm madly trying to sort this oil cooler, thinking remote filter setup at the moment, just need to price stuff up etc

Yeah as you have the exhaust pipe thats to tight, go remote filter like Emma has and just make sure its a thermostatically opening one, that means it will still filter the oil but return it the the engine uncooled until it reaches 80degrees, when we ran Emma's car no cooler but had temp gauge we saw 145 on run from Northampton to Milton Keynes and thats only 15 miles on M1.

now with cooler on we don't see above 110 which is right.

 

[beastyjay]

when my headgasket went it was off the clock on temp gauge..looked about 150ish

 

[randomizered]

Im fitting a temp dial at the mo, where have you installled an oil temp guage? a sump adatper or something more fancy??

Kristian

 

[randomizered]

when my headgasket went it was off the clock on temp gauge..looked about 150ish

Did you not stop instead?

 

[guyinbelfast]

haha...must have started something and was only rambling anyway. No only posted for those people who freak out when the temp hand goes over 80C...

 

[Steven]

On most Fiats the usual operating temp is around 90.

Guy, what sort of Fiat did you spot the Fiat Forum sticker on that led you to this site?

 

[J333EVO]

Im fitting a temp dial at the mo, where have you installled an oil temp guage? a sump adatper or something more fancy??

Kristian

oil temp gauge is easy to fit to a Cinq as you have two M18 1.5 Allen bolts below filter housing, the top one on turbo Cinqs is used as an oil feed, so i used the bottom one as oil temp gauge sender, but had to buy a M18 adaptor from Demon Tweeks for about £6 as you do not get any that big with the assortment of fittings you get with gauges, well i didn't anyway with mine.

http://www.demon-tweeks.co.uk/products/ProductDetail.asp?cls=MSPORT&pcode=LMA068

 

[beastyjay]

Did you not stop instead?

nah was going anyway lol

 

[woodins]

LOL Beasty at least yours didnt go half-way through the Blackwall tunnel

One minute the temp gauge was on 90 next thing it was off the clock!!!!

The Old Bill had to tow me out

Should be picking it up end of this week i hope.

 

[randomizered]

Cheers J333EVO, I will have a look on the weekend if its the same on my Sei. Could be fun to have an oil alongside the temperature pod, if not completly pointless....at least it may make them fit asthetically having two

Kristian

 

[J333EVO]

Cheers J333EVO, I will have a look on the weekend if its the same on my Sei. Could be fun to have an oil alongside the temperature pod, if not completly pointless....at least it may make them fit asthetically having two

Kristian

Its the same, even the 1368cc 16V has the same take offs