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  • Fox 5.0 Mustang Tech

Engine Running hot and driving me crazy

  • Thread starter Thread starter bad_decision
  • Start date Start date May 15, 2021
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General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
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#21
  • Nov 25, 2021
  • #21
Every time I swapped intakes, changed senders or thermostats my gauge read different. I refer to them as a 'best guess'.
 

KRUISR

10 Year Member
Apr 16, 2015
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#22
  • Nov 25, 2021
  • #22
I agree with the General, the factory gauge is a best guess. I would take a temperature reading on the driver side rad tank (metal part). That would be your best info.

View: https://www.youtube.com/watch?v=2P7MDRXmfI4&t=6s


The start of the video my fans had automatically triggered (205 *F), you will see where my gauge is reading.
 
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91AOD5.0LX

I have a slight sag in my rear
5 Year Member
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Dec 12, 2021
#23
  • Dec 12, 2021
  • #23
Removed the factory 195 degree thermostat and installed a high performance 180 and she runs super cool now. Notch below the middle.
 

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Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
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Dec 12, 2021
#24
  • Dec 12, 2021
  • #24
91AOD5.0LX said:
Removed the factory 195 degree thermostat and installed a high performance 180 and she runs super cool now. Notch below the middle.
Click to expand...

I went from a 180 to a stock 195 and this is exactly where my needles sat as well.
 
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Potomus Pete

I'm still waiting for the fully nude shots
5 Year Member
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Dec 12, 2021
#25
  • Dec 12, 2021
  • #25
Mine is on the R...Could this be OK, and normal.
 

7991LXnSHO

wanna catch the space herp
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Dec 12, 2021
#26
  • Dec 12, 2021
  • #26
Potomus Pete said:
Mine is on the R...Could this be OK, and normal.
Click to expand...
Yes.
 

KRUISR

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#27
  • Dec 12, 2021
  • #27
Potomus Pete said:
Mine is on the R...Could this be OK, and normal.
Click to expand...
That's where mine is (in the video above). Mine used to be at the M, but after I put a new temp sensor on normal moved up to the R. I am using a 180 T-stat.
 

91AOD5.0LX

I have a slight sag in my rear
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#28
  • Dec 12, 2021
  • #28
Potomus Pete said:
Mine is on the R...Could this be OK, and normal.
Click to expand...
Sure. “R” Seems to be where most are at. Mine was at the R all the time and was always fine. I always kept one eye on it though where as the new reading, on the A, makes me feel a lot more comfortable.
 

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Potomus Pete

I'm still waiting for the fully nude shots
5 Year Member
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#29
  • Dec 12, 2021
  • #29
Mine used to be on A until I put a new temp. sensor. Then it jumped up to R after the new sensor. So who knows what the real reading is
 

91AOD5.0LX

I have a slight sag in my rear
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Feb 20, 2021
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Dec 12, 2021
#30
  • Dec 12, 2021
  • #30
Potomus Pete said:
Mine used to be on A until I put a new temp. sensor. Then it jumped up to R after the new sensor. So who knows what the real reading is
Click to expand...
100% right about that. Accuracy of the gauges... who knows!?!??! Now ya have me thinking... ok, not going down that rabbit hole. Lol
 

General karthief

wonder how much it would cost to ship you a pair
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Dec 12, 2021
#31
  • Dec 12, 2021
  • #31
I don't understand, why guess, put a mechanical or electric temp gauge in, you can mount it to the bottom of the dash or a pillar pod and know what temp the engine is running, and keep the factory gauge.
 

Potomus Pete

I'm still waiting for the fully nude shots
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#32
  • Dec 12, 2021
  • #32
If it's getting above average hot you will smell/feel it. I have a Moroso radiator cap with a thermometer on it. Always interesting what that reads. Usually a lot less
 

91AOD5.0LX

I have a slight sag in my rear
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#33
  • Dec 12, 2021
  • #33
In relation.... let me ask this..... when your cold, is your coolant in the bottle actually up to the “full when cold” line and when your hot, is your coolant up to the “full when hot” line????
Mine never is... either way... it’s always way down under the cold line regardless if she’s hot or cold and I’m not low on coolant.... same or different for you guys?
 

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Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
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Dec 12, 2021
#34
  • Dec 12, 2021
  • #34
I don’t have a stock bottle anymore, but when I did, i would top the bottle off to full hot when the motor was warmed up. It would them drop down but i would never pay attention to that level.

I typically do this to all my cars and adjust overflow level so it’s even with full hot when motor is hot.
 
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91AOD5.0LX

I have a slight sag in my rear
5 Year Member
Feb 20, 2021
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Lake George NY
Dec 12, 2021
#35
  • Dec 12, 2021
  • #35
I don’t have a stock bottle anymore, but when I did, i would top the bottle off to full hot when the motor was warmed up. It would them drop down but i would never pay attention to that level.
Mustang5L5 said:
I typically do this to all my cars and adjust overflow level so it’s even with full hot when motor is hot.
Click to expand...
Ok thanks for your input. I’m always tempted to add and bring it up to where it should be but then at the same time wonder if that’s not accurate either (the line) and figure leave it alone if there are no issues... maybe i should bring it up to the hot line then.... was curious about others so that’s for your comment on this.
 

Dan02gt

mazing how much gas smell came from that tiny hole
20+ Year Stangneter
Mar 2, 2003
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Greenville, NC
Dec 14, 2021
#36
  • Dec 14, 2021
  • #36
I have the factory 195* thermostat and mine sits right on the A when warmed up. When I read the engine temp via the ECT using my Quarterhorse the A is ~185*.
 
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Boostedpimp

20+ Year Stangneter
May 8, 2003
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Dec 14, 2021
#37
  • Dec 14, 2021
  • #37
I'm a fan of underdrive pullies. I daily with them but I feel you need a decent electric fan and alt upgrade to use them otherwise they'll bring to light any charging system or cooling system weaknesses you may have if any.
 

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Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,255
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Massachusetts
Dec 14, 2021
#38
  • Dec 14, 2021
  • #38
I’m not opposed to U/D pullies at all if your cooling and charging system is robust.

And I’ll probably be installing a set shortly as I drank a weee bit too much the other day and ordered a 93 cobra pulley set, which is 11% underdrive (typically most sets are roughly 25%)
 
Reactions: Boostedpimp, General karthief and 91AOD5.0LX
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Chuckster101

Member
Oct 3, 2024
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St. Aug. Fl. 32084
Feb 27, 2025
#39
  • Feb 27, 2025
  • #39
Retired diesel mech . . Seen the trend to run any engine,gas or diesel. Hotter . When fuel mileage became forefront on the industry as high temps produce more hp. And fuel mileage also gains . However the downsides are that you are running on a fine line of damage to your engine. Idiot lights and inattentive monitoring of real gauges give the operator a lot lellsslsll time to notice that something went wrong when normal is 210 f …. And 220 is damaging. Personally i street drive and therefore run a cooler thermostat and cooler fan sensors . I take a slight knock on performance (5hp.) or so and burn a little more fuel but I value my engine and I need not keep my eyes glued to the dash . Watch the people who are using their cellphone.. going to the track? Different story entirely ! I don’t have a computer controlling my engine,just my right foot .
 

limp

wrap a little cheese around it and its a done
5 Year Member
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Feb 27, 2025
#40
  • Feb 27, 2025
  • #40
If your car has a computer you need to have it programmed for a cooler temp thermostat.... IF not it senses that the car is still cold or needs some choke and will richen the mixture...
 
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