• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific Tech

Over flow coolant tank level question

  • Thread starter Thread starter DanG
  • Start date Start date Oct 11, 2011

DanG

Founding Member
Oct 8, 2000
694
0
17
Maryland
Oct 11, 2011
#1
  • Oct 11, 2011
  • #1
Long story short, I got the car back from the dyno a few weeks ago, where the shop also finished off a few odds and ends for me, including initial start up of the car after 8 years, evac system install for the valve covers, and pour in coolant. ( I gave them the car w/o coolant in the event they needed to pull anything in the motor )
Anyways, the coolant over flow tank is empty, and has always been empty since I got the car back. I'm assuming that this is fine, as the purpose of the overflow tank is just that, over flow.. Is this correct?
 

SableSal

Member
Sep 17, 2009
295
3
19
Fresno, Californ-I-A
Oct 11, 2011
#2
  • Oct 11, 2011
  • #2
Well, kinda. The tank is designed so that over flow will get poured in to the tank, but if the radiator needs coolant it will suck from the tank. Just make sure your radiator is filled to the brim. You'll be ok.
 

revhead347

Apparently my ex-husband made that mistake.
20+ Year Stangneter
Jun 14, 2004
9,289
1,632
214
Acworth, GA
Oct 11, 2011
#3
  • Oct 11, 2011
  • #3
Should be about half full.

Kurt
 

4rdnut

Member
Dec 14, 2010
188
1
16
Oct 11, 2011
#4
  • Oct 11, 2011
  • #4
When your engine cools down, vacuum is formed and pulls coolant from the overflow tank, if the tank is empty the engine sucks in air which causes air pockets to form in the heads causing hot spots. Keep coolant level at the cold level in overflow tank when engine is cold.
 
Reactions: DarthStang2003

VibrantRedGT

"STANGNET'S PENGUIN SMACKER"
15 Year Member
Nov 29, 1999
14,679
424
154
Boca Raton, Florida
Oct 12, 2011
#5
  • Oct 12, 2011
  • #5
That tank is your insurance policy, make sure it's half full like mentioned. If the motor does need coolant is going to get it from the tank. I would never drive with an empty overflow tank, that's asking for trouble.

The reason why it's empty I'm sure they sure didn't burp the system correctly. They probably filled up the radiator and tank. After the stat opened a few times it needed coolant and sucked the tank dry.
 

4Jenna

Founding Member
Sep 12, 2001
4,326
6
69
AZ
Oct 12, 2011
#6
  • Oct 12, 2011
  • #6
I agree!
 

DanG

Founding Member
Oct 8, 2000
694
0
17
Maryland
Oct 12, 2011
#7
  • Oct 12, 2011
  • #7
Sounds good guys. Thanks for the replies. I'll go home this evening and put in a coolant/water mixture.
 

4Jenna

Founding Member
Sep 12, 2001
4,326
6
69
AZ
Oct 12, 2011
#8
  • Oct 12, 2011
  • #8
I'd recc Purple Ice and or water wetter also if you dont already have it in there!
 

DanG

Founding Member
Oct 8, 2000
694
0
17
Maryland
Oct 12, 2011
#9
  • Oct 12, 2011
  • #9
4Jenna said:
I'd recc Purple Ice and or water wetter also if you dont already have it in there!
Click to expand...

I don't have either. Thanks for the recommendation. Purple Ice almost sounds good enough to eat....err... Gotta stop typing out loud...
 

VibrantRedGT

"STANGNET'S PENGUIN SMACKER"
15 Year Member
Nov 29, 1999
14,679
424
154
Boca Raton, Florida
Oct 12, 2011
#10
  • Oct 12, 2011
  • #10
Do a 60/40 mix, 60 water / 40 coolant, buy 2 bottles of Water Wetter, properly get the air out of the system and you should be golden.

Start the car with the radiator cap off, when the thermostat opens, fill radiator to the top, put the cap back on. Do it quickly before the stat closes and starts pushing the coolant out of the radiator then you'll have a mess.
 

chaos254

Founding Member
Jul 27, 2002
467
3
29
NJ
Oct 19, 2011
#11
  • Oct 19, 2011
  • #11
what about you guys that are not running a stock overflow? Most are only a quart.... still fill it half way?
 
You must log in or register to reply here.

Similar threads

M
01 mustang 3.8 fuel pressure issue
  • Mhaley2006
  • May 29, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
71
1996 - 2004 SN95 Mustang -General/Talk- May 29, 2026
Mhaley2006
M
Help! Intake Manifold Gasket or Head Gasket?
  • foxbodyclark
  • Oct 4, 2024
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
10
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 4, 2026
95 Laser GT Ver
B
'03 GT Fuel Pump/Pressure/Delivery Issue
  • Brodach
  • Oct 21, 2025
  • SN95 4.6L Mustang Tech
Replies
8
Views
837
SN95 4.6L Mustang Tech Oct 31, 2025
gkomo
Tuners come on inside
  • squeak93
  • Feb 13, 2026
  • SVT Tech Forum
Replies
1
Views
225
SVT Tech Forum Feb 20, 2026
squeak93
S
Requesting Guidance for 306 motor swap - Fuel? - SD? MAF?
  • So_Flo
  • Jul 26, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
32
Views
2K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 4, 2026
Mcmahst
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?