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91 deville runs a little hot

990 Views 5 Replies 4 Participants Last post by  adalla
New radiator and fuel pump. And total system flush from the top to the tee in the last year. Still seems to be running a little hot. Anyone experienced anything similar. Also, someone mentioned attaching a temp gauge to the car, and I'm not real sure how to do this other than checking coolant temp on the ECC. What's the operating range for the 4.9?
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At highway speeds around 190 degrees. What are your temperatures and driving pattern?

Flush may result in wrong antifreez concentration after refilling.
my 93 Eldo with the 4.9 runs around 203 highway and about 220 around town. The thermostat doesnt usually open till about 228-230.
D'Elegance said:
my 93 Eldo with the 4.9 runs around 203 highway and about 220 around town. The thermostat doesnt usually open till about 228-230.
The OEM thermostat should keep it around 195. 10 degrees difference is not a big deal though...
I have a 94 deville 4.9 and I just got from a 100 mile trip and on the highway the car ran around 185 but when I got off on the exit and stopped at the first light the temp shot up to 226 till it finally started coming down but is that to high and should I change the thermostat?

Thanks in advance
devilleman1024 said:
I have a 94 deville 4.9 and I just got from a 100 mile trip and on the highway the car ran around 185 but when I got off on the exit and stopped at the first light the temp shot up to 226 till it finally started coming down but is that to high and should I change the thermostat?

Thanks in advance
Do not touch anything. Everything is perfectly normal. When you stop there is no air flow through th eradiator and th etemp will climb pretty fast. At 226 the cooling fans start and bring it down to some 212 and turn off. Mine used to do 194 at highway speeds (flat terrain). I changed the OEM stat to lower temp one and now get 186 at highway speeds.
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