Hemi 5.7 Coolant temp question

[SumpChump]

2095 Ram 1500 hemi 5.7...new to me now at 98k miles.

Is 203F an acceptable safe coolant temp at hoghway full warm operation?? 65 mph 1700rpm 75F ambient.

Dummy guage reads just below middle, obd reads 203F.

Sounds safe and reasonable? Thanks!

 

[Inspecktor]

My 06 Dakota 4.7 runs at 204F via OBDII, dash reads just under halfway. With A/C on, will go as high as 212F on hills.

 

[SumpChump]

Originally Posted By: Inspecktor
My 06 Dakota 4.7 runs at 204F via OBDII, dash reads just under halfway. With A/C on, will go as high as 212F on hills.


Thanks!

And i believe fans come on in two stages starting at 209F iirc.

 

[Olas]

212f is boiling at 1atm but the boiling point rises with pressure, generally safe to 220/225ish..
Flush and fill and thermostat for certainty that it's right

 

[demarpaint]

Not a Hemi, but my 3.6L Rubicon will go up to 224F in heavy traffic, IIRC the fan kicks in at 226F. Highway cruises the temps are between 199-204F. They want them to run hot.

 

[xxch4osxx]

My 2015 Ram 5.7 will run anywhere between 199 to 214 going down the road in the summer. It goes up and down all the time. That is going by the digital gauge in the dash.

 

[AntsinmyEyes]

Did you mean 2005? If so the stock thermostat is 203 degrees Fahrenheit and in traffic they can creep up to around 220 degrees. I believe this is just slightly over the halfway mark on the coolant temp gauge (this is the highest ive seen mine go after idling for a half hour with ac on on a 90 degree day).

 

[CT8]

Coolant and the pressure cap raise the boiling point so that is not too hot.

 

[Chris142]

I'd consider up to 240 OK.

 

[SEMI_287]

Normal. Chrysler designed these motors to run warm with MDS. The warm block temps keeps cylinder wear in check because when the MDS is on 4 cylinders are not being used. With those cylinders deactivated the bores aren't up to temp. Warmer engine temps help to counteract this. My 300C will creep around 220 before the fans kick in in the summer.

 

[Nyogtha]

My 2012 5.7L Ram recently completed a trip from Ohio to Texas towing a 5' X 8' U-Haul and highest coolant temp. I saw on the digital gauge was 215°F when travelling around 80 MPH on I-35 in Texas. Analog style gauge was about half of range.

 

[SumpChump]

Thanks guys!