Thanks for using Just Answer. I will be glad to assist you.
Good news!! I don't believe that you're having a head gasket problem.
I believe that your issue is with the coolant temperature sending unit for the gauge. The sensor sends the information to the gauge to display the coolant temperature.
There is a technical service bulletin issued by Ford for your vehicle because of defective coolant temperature sending units. A new part has been created and it should be replaced. Please refer to the TSB information below:
|^||GAUGE - TEMPERATURE-READS IN LOW RANGE - ERRATIC READINGS |
|^||SERVICE PARTS - RETURN OF OBSOLETE TEMPERATURE SENDERS |
1981-95 MUSTANG, THUNDERBIRD
1983-95 CROWN VICTORIA
1981-92 TOWN CAR
1983-95 GRAND MARQUIS
1984-92 MARK VII
1993-95 MARK VIII
1990-95 F-150-350 SERIES
Temperature Sender F1SZ-10884-A with a build date code prior to 2774 (277th day of 1994) should be purged from your inventory and returned to your facing PDC. These parts are being made obsolete because of an incorrect crimp during assembly. Installing these parts on a vehicle could result in early loss of temperature sender function.
Remove and return the suspect parts from your dealership's inventory. The obsolete parts should be withdrawn from your inventory and returned to your facing PDC within 30 days of this TSB.
NOTE : USE TSB ARTICLE 93-24-8 FOR DIAGNOSIS PROCEDURE IN DETERMINING IF LOW GAUGE READINGS COULD BE ASSOCIATED WITH A TEMPERATURE SENDER CONCERN.
|1.||Perform 100% sort of all stock on hand. |
|2.||Suspect stock has a build date code prior to 2774. Usable stock will have a build date code of 2774 or later. |
: DATE CODES ARE LOCATED ON THE SIDE OF THE SENDER HEX.
|3.||Usable stock can be returned to your inventory and released for normal sales. |
|4.||Return suspect part (F1SZ-10884-A) to your facing PDC using the least expensive transportation. |
|5.||If claim is processed electronically via DOES II, use return code "GB"; otherwise, complete a separate paper claim form FPS-340 using return code "J". |
|6.||In the Remarks Section, write "Returned per TSB 95-13-2". |
|^||The returns must be received within 30 days from the date of this TSB. |
|^||Returns are restricted to the subject parts. |
|^||The parts returned must have been purchased from FCSD in accordance with Policy and Procedure Bulletin 4000. |
Credit for parts and prepaid freight costs will be issued.
Replacement stock is available for ordering
PART NUMBER PART NAME F1SZ-10884-A Temperature Sender
OTHER APPLICABLE ARTICLES: 93-24-8
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 203000, 203200, 204000, 204200, 402000
Here is the inspection procedure to test the coolant temperature sending unit: