Cooling system thumping

[keithtaylor]

I have a 1991 Explorer and I need all the help I can get with a cooling problem. Every so often after I drive my explorer when I hit a stop and am idling or sometimes while driving, I will hear a thump coming from my cooling system. Also to go along with this problem I have a cycling temperature gauge. It will go to about a 1/2 or so up back down to about 1/4 and keep going through this cycle. I have replaced just about everything I can think of to fix it, even had it to a mechanic. So far on the list of new components are:

Radiator
Fan
Fan Clutch
Waterpump
Radiator cap (2)
Thermostat (3)
Radiator hoses

I need all the help I can get!!!!!
any suggestions???

 

[Jason_25]

Cooling System - Thump Noise/Gauge Fluctuation
Article No.
97-18-9

09/02/97

^ COOLING SYSTEM - TEMPERATURE GAUGE FLUCTUATION - VEHICLES WITH 4.0L ENGINE

^ NOISE - "THUMPING" HEARD FROM WATER PUMP AREA - VEHICLES WITH 4.0L ENGINE

LIGHT TRUCK:
1994-97 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

F0TZ-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 1.3 Hrs.
Gasket - Ranger And Explorer

971809B Replace Water Pump And 2.1 Hrs.
Gasket - Aerostar

DEALER CODING
CONDITION
BASIC PART NO. CODE
8501 42

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

 

[keithtaylor]

So what you are saying is that the "New" waterpump I put in this darn vehicle is in someway designed wrong for my Exploder? I work at a parts store and bought a brand new one off the shelf for it and if I am understanding you correctly your saying I need to replace it with a specific one? Help me please

 

[RiverRat]

I had a temp gauge that cycled from cold to normal. I did the tsb and it now reads normal all the time.

 

[keithtaylor]

Forgive my ignorance, but what is "tsb" ? I would love to do that if it helps thanks!

 

[RiverRat]

Originally posted by keithtaylor
Forgive my ignorance, but what is "tsb" ? I would love to do that if it helps thanks!

It's what Jason_25 posted TSB 97-18-9.
Technical Service Bullitin. Ford issues these when they know or have enough people complain about a problem.

 

[keithtaylor]

Where can I find the info? I am new to this forum and I am unsure of how to seak it out

 

[keithtaylor]

I guess one other thing I should mention is that my vehicle will "thump" after the engine is shut off...for at least a minute on some occasions....I just am so frustrated with this problem. I love my Explorer, but I hate the problems it's creating.

 

[RiverRat]

I just looked at the TSB Jason posted. It only applies to 1994-1997 trucks so it might not fix your problem. I don't know what to recommend other than using motorcraft parts (t-stat, pump) and make sure the cooling system is purged of all air. I'm sure someone here has info on getting the air out of the cooling system.

 

[keithtaylor]

Thanks for your help RiverRat. I really need some help on this thing. My mechanic is stumped and so am I!

 

[keithtaylor]

I am still trying to figure this out....any more advice would be great!

 

[biggs85]

I would try to get the air out of the system. Search for air bubble, burp, or something like that and you will find out how to do it.