Temp Fluctuations

[Gabe96Explorer]

my 96 v6 4x4 x.

This literally happened over night. Not burning oil, oil is good colored. Not blowing smoke.

Found my radiator and my coolant overflow drank about a gallon of water between the 2 (I only checked the system because of the issue below, and only had water on hand. I only use antifreeze)

This does the same with and without heat running.

The temp guage will shoot up to about 3/4 of the total gauge length (way above normal operating temperate) but has never gotten above that or over heated.

Then shoot down to just under normal operating temp.

My fan spins freely while off, with little to no resistance. It spins as soon as I start it cold and continues to spin when I shut the motor off. Bad Fan Clutch?

Should probably replace t-stat too?

Time sensitive on this.

 

[Gabe96Explorer]

Now only happens when heat is on. When the heat is off, it fluctuates between 1/4 and half of the total gauge length. Its weird....

Replaced fan clutch (it was deff bad) and its still doing it. Going to try a new thermostat tomorrow.

 

[swetrid]

Ford has tsb.
Printable View (4 KB)
TSB
97-18-9 COOLING SYSTEM - TEMPERATURE GAUGE FLUCTUATION - VEHICLES WITH 4.0L ENGINE
NOISE - "THUMPING" HEARD FROM WATER PUMP AREA - VEHICLES WITH 4.0L ENGINE

Publication Date: SEPTEMBER 2, 1997

LIGHT TRUCK: 1994-1997 AEROSTAR, EXPLORER, RANGER


ISSUE:
A "thumping" noise or temperature gauge fluctuation may occur on some vehicles. This may be caused by the water pump delivering an uneven flow throughout the engine.

ACTION:
Replace water pump and gasket with revised Water Pump (F7PZ-8501-AA) and Gasket (FOTZ-8507-A). Refer to the appropriate year Aerostar/Ranger/Explorer Service Manual, Section 03-03, for water pump replacement procedure.


PART NUMBER PART NAME
FOTZ-8507-A Water Pump Gasket
F7PZ-8501-AA Water Pump


OTHER APPLICABLE ARTICLES:
NONE

WARRANTY STATUS:
Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME
971809A Replace Water Pump And Gasket - Ranger And Explorer 1.3 Hrs.
971809B Replace Water Pump And Gasket - Aerostar 2.1 Hrs.

DEALER CODING
BASIC PART NO. CONDITION CODE
8501 42

OASIS CODES:
204000, 204200, 402000, 497000, 702100


--------------------------------------------------------------------------------

Copyright © 1997 Ford Motor Company

 

[Gabe96Explorer]

Fml.

 

[Gabe96Explorer]

Anyone know what the pump will cost at a dealer? Autozone is like $45?

 

[marragtop]

Before doing the pump, I suggest replacing the Tstat and make sure you burp any air out of the system.

 

[FarmTruk]

Before doing the pump, I suggest replacing the Tstat and make sure you burp any air out of the system.

x2


Sounds just like a wonky t-stat to me.

Sticky t-stat won't open, won't open, won't open, all the while the water temp is rising.

Then, all of a sudden, it gets hot enough and opens...wham...temps fall back to normal.

Same same for running cool. Sticky t-stat stays open, stays open, stays open...then wham, it closes, and water temps begin to rise to normal again.



Just a note....if you DO decide to replace the t-stat, bench test it on your stovetop first. Drop it into a pot of water, bring to boil, and determine at what temp does it open using a kitchen thermometer.

I've had brand new t-stats fail right out of the box. Better to find this out before you install it.

 

[Gabe96Explorer]

That is what we plan on doing. So I am going to pre boil some water and see what it does.

 

[FarmTruk]

Bring the water to a boil with the t-stat already in the pot. The t-stat should open(~190*F) a little before the water boils (212*F).

Leave it in as the water cools to check for proper closing temp as well.

 

[Gabe96Explorer]

My tstat was bad. It was very sticky. Opened at about 250f

The new one was good. it opened at about 187f

Car still fluctuates just not as hot or high up the guage... going to flush out the coolant with some new green 50/50 and see where that gets me.