Coolant Temp
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Elder User
Joined: May 2008
Posts: 550
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From: Sioux City, IA
Coolant Temp
I bought my scangaugeII about 2 weeks ago. Then my ECT ran at 190-191 and my EOT ran anywhere from 196-201. Now my ECT has trouble staying at 190. It will hit 190 then drop back down to 184-188 and go back and forth. My EOT has also dropped to 192-198. The temp outside have dropped to 20-40 degrees. What do you guys think? Is my thermostat going out? Or is it just the cold temperatures? My driving consists of a mix of in-town and highway all day.
More Turbo
Joined: Aug 2009
Posts: 551
Likes: 19
thermostat springs get weak over time, you're not that far out of spec, but you never posted your ambient temp either.
6.0 thermostats are supposed to be 195f, and diesel engines like running to thier speced temp, so just keep an eye on it. its only a $20 part and any time coolant is flushed the thermostat should be changed, last winter my stat stuck open at -15f, so i combined a flush with changing it out.
6.0 thermostats are supposed to be 195f, and diesel engines like running to thier speced temp, so just keep an eye on it. its only a $20 part and any time coolant is flushed the thermostat should be changed, last winter my stat stuck open at -15f, so i combined a flush with changing it out.
Hotshot
Joined: Jul 2005
Posts: 13,834
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From: Middle Tn.
For optimum fuel economy you would be better off with ect's in the high 190's to low 200's, however, it is cold out there. We don't have those sustained cold temps here in s. ca. but it looks like the t-stat could be getting a little on the flakey side. No rush on it as long as your monitoring the temps.
Senior User
Joined: Jun 2010
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I replaced my thermostat yesterday and ECT is staying at about 188 to 190 as its cold outside. 22-32 degrees.
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Lead Driver
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From: Ouray, CO
Before changing my thermostat, ECT 182, EOT 188 (80-90* ambient)
After thermostat replaced: ECT folds @ 190, EOT 198+
(after warm-up EOT varies up to 205 on interstate)
Until the engine is totally warm, you can tell when the thermostat opens,
my ECT goes to 188 or 189 then back to 190. Turn on the heat, same
things happens (all normal IMO).
After driving for a while ECT stays right @ 190.
My EOT pegs @ 205 @ 75MPH, new Oil cooler in a week or two.
Stop in a traffic jam caused by accident (tourist season in FL
)
and my ECT might drop to 189 and then go back and the EOT
will start to drop from 205 to 189 as it cools off while everybody "gawks".
After thermostat replaced: ECT folds @ 190, EOT 198+
(after warm-up EOT varies up to 205 on interstate)
Until the engine is totally warm, you can tell when the thermostat opens,
my ECT goes to 188 or 189 then back to 190. Turn on the heat, same
things happens (all normal IMO).
After driving for a while ECT stays right @ 190.
My EOT pegs @ 205 @ 75MPH, new Oil cooler in a week or two.
Stop in a traffic jam caused by accident (tourist season in FL
)and my ECT might drop to 189 and then go back and the EOT
will start to drop from 205 to 189 as it cools off while everybody "gawks".
Junior User
Joined: Nov 2010
Posts: 80
Likes: 0
I bought my scangaugeII about 2 weeks ago. Then my ECT ran at 190-191 and my EOT ran anywhere from 196-201. Now my ECT has trouble staying at 190. It will hit 190 then drop back down to 184-188 and go back and forth. My EOT has also dropped to 192-198. The temp outside have dropped to 20-40 degrees. What do you guys think? Is my thermostat going out? Or is it just the cold temperatures? My driving consists of a mix of in-town and highway all day.
Elder User
Joined: Sep 2004
Posts: 821
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From: Nashville
Mountain Pass
Joined: Jun 2009
Posts: 119
Likes: 2
From: Calgary, Alberta
Normally my ECT will sit around 188 with the EOT 2-3 degrees higher. However until a few days ago we had temps down from 5 to -5 degrees (F) and my temp never got above 168 but it never fluctuated. I blocked the grill with a winter front to help keep the wind off the grill.
Junior User
Joined: Nov 2010
Posts: 80
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Normally my ECT will sit around 188 with the EOT 2-3 degrees higher. However until a few days ago we had temps down from 5 to -5 degrees (F) and my temp never got above 168 but it never fluctuated. I blocked the grill with a winter front to help keep the wind off the grill.
