Maximum safe engine temperature?

Status
Not open for further replies.
Joined
Jan 27, 2005
Messages
489
Location
Quebec, Canada
Saw my engine temperature (on my ScangaugeII) jump from a normal 82C to as high as 101C last night while driving from Plattsburgh NY to Montreal in a snow storm. Speed was in the 60-80 Km range and RPM around 1500 the whole way.

The engine temp gauge needle still sat 1/8" below the half way point as usual. The radiator and front of the car was getting blocked by snow. I stopped once at the border to remove what I could and engine temp quickly went down to 80C afterward but gradually went back up to 96-98C and to 100-101C. Conditions were too nasty and unsafe to stop again so I turned up the heat in the cabin and cracked my window. I was at 95-96C when we got home. Here's is a shot on my engine compartment:




No light appeared on the dashboard and coolant and oil levels checked out OK this morning.

How high would be unsafe?
 
Last edited:
Unsafe would be where your check engine light came on. My Chev has an actual digital temp gauge. I have seen it as high as 104C without the fan coming on to assist. When it gets that high in bumper-to-bumper summer traffic, I just turn on the AC. The temp then quickly drops to 90C. If I'm already using AC in heavy traffic, it won't go to more than 92C.
 
It all depends on the engine design, but 101C is just a tad over boiling. No big deal at all. Many engines are designed to run right at 100C. The usual "danger zone" for NASCAR engines (yes, its not a very direct comparison...) is around 230-240F (110-115C)
 
Not much you frozen suckers can do, all I can say is instead of driving north in a blizzard is to drive south to FL. It is about 76F where I'm at today.

You know I'm only playin' 101C is fine, keep an eye on it and be safe out there.
 
pressurized cooling systems raise the boiling point of the coolant/water mix. With a little google searching, you can find a chart that shows what the boiling point would be at for certain pressures

If I remember right, a proper mix and a 14-15psi pressure cap, will raise the boiling point to 245-250 degrees F.
 
Last edited:
You're fine. But when it all melts out make sure your electric rad fan turns. If it got jammed with snow it could have burnt the motor out.
 
My electric fans don't come on until over 105c. I would check that the fans fuse didn't blow from being blocked, should be fine.
 
100c or 212F is normal. No worries there. My Jeep often runs 230F on a hot day in Death Valley,Ca. 240F if I'm stuck in traffic with the AC on.

I consider 240F my max comfort temp. Anything over that and I get it into the wind.

Many GM cars don't turn the low speed fan on untill 225 and the high speed fan at 235.
 
Last edited:
That seems normal, considering he conditions.
212 is nothing.
Sure, 195 is more normal, but I would not think twice about an occasional bit more.
 
Like others have said, 101C is absolutely nothing to worry about. Still completely normal. Cooling fans often don't come on until 105 to 110C.
 
Originally Posted By: chubbs1
Not much you frozen suckers can do, all I can say is instead of driving north in a blizzard is to drive south to FL. It is about 76F where I'm at today.

You know I'm only playin' 101C is fine, keep an eye on it and be safe out there.


LOL, I was driving back from the Plattsburgh Airport to Montreal because our flight to FLORIDA had been canceled! We
were rebooked the next day and I am writing this from FL today but it`s not that warm overhere...

Anyhow, the Fe drove great on Sunday back to Plattsburh on dry pavement and engine temp was back to 82C.
 
Normal running temp for a lot of vehicles (such as my Jeep) is 210* F, so just under 100* C. Unless it hits 230* F or hotter, or is running sustained over 220 - 225* F, it's not an issue for most engines.
 
Hi,
Minou - All engines will vary somewhat with most of today's Euro engines runing around 93C as "normal". My Boxster typically sees around 100C without fans on and around 105C (it purposely runs hotter than normal) - most run at around 92-96C.

As an example the Porsche 928 (V8) has a very complex cooling system. The S4 version (digital dash - fans/flaps controlled via computer) has an initial warning at 118C and another demanding shut down at 120C

(BMW M3s were even allowed oil temps of around 130C during the 1990s!)

Heavy high speed diesel engines typically run at around 96C before their air operated fans activate (chip driven) and have a automatic powerdown/shutdown at around 105-110C. My trucks averaged around 88-90C

Operating around 90-95C has many benefits considering it is not so long ago that 76C was accepted as "normal" - and engine sludging was quite common

In your case no damage would have been done but sufficient airflow is a critical part of cooling system efficiency. I have seen radiators frozen solid and the Driver wondering why the coolant is boiling!
 
Status
Not open for further replies.
Back
Top