So I've owned this 97 Exp with 5.4 since new. At approx 230k heater core went out. I replaced that myself.

Approx 10k later radiator started leaking which seemed pretty coincidental. Purchased it from a friends shop and installed myself. Approx 3k later smelled antifreeze. Found many pinhole leaks in radiator. Friends shop replaced. 3k later smelled it again. They've replaced it 4 TIMES. The last time he called the manufacturer and we paid a little extra for a "better one".

The guy working on it said it had to be a head gasket but when it was tested for hydrocarbons it was negative.

Hoped for the best with the last one but tonight it smelled again and we could see the leak at the bottom right side of the radiator. The temp gauge has never wavered from the middle of the scale. I replaced the radiator cap when we installed the last radiator as I've always thought the upper radiator hose felt very firm, almost rock hard.

There has been no loss of fluid in the 4k miles and no smoke in the exhaust. Oil and coolant look completely normal. Could a head gasket leak only over pressurize the system and not have other symptoms? Or could this be one, the heat output feels, to me, very very hot. Any thoughts? Could it be a stuck thermostat? Wouldn't that show up on the guage? Water pump has been replaced but not recently. Should I try a Ford radiator? Been a great truck but this is really crazy.

Thanks.

 

With the correct radiator cap, the coolant system shouldn't pressurize any higher than 16 psi. When I blew a head gasket, the system was over pressurizing and the coolant was forced out at the radiator cap on the Degas bottle.

I would suggest getting a good quality OEM radiator.

 

You need to do a leak down test on all cylinders and find the variations, the cylinder with the most and fastest leakage is likely the culprit if there is a head gasket problem. You could also try using a 2 piece compression tester and remove the guage, hook it directly to an air line and pressurize each cylinder and look for bubbles or air escaping in the degas bottle. I believe you can borrow both tools from Advance Auto Parts but you will need an air compressor.
With a leak down test you will know the condition of the top end of your engine if nothing else. That's a good thing.

 

Assuming you're not constantly running radiator flush through the system, you're getting junk radiators, pure and simple. A blown head gasket would pump the anti freeze out of the bottle first, or blow a hose.

 

it sounds like electrolysis there is a tsb for this problem tsb 06-21-19

 

HEATER CORE LEAKAGE AND ELECTROLYSIS TSB 06-21-19
(INFORMATION ONLY)
FORD: LINCOLN:
1997-2002 Contour 1997-2002 Continental
1997-2007 Crown Victoria, Mustang, Taurus 1997-2007 Town Car
2000-2007 Focus 2000-2006 Lincoln LS
2002-2005 Thunderbird 2006 Zephyr
2005-2007 Five Hundred, Freestyle 2007 MKZ
2006-2007 Fusion 1998-2007 Navigator
1997-1999 F-250 Light Duty 2002-2003 Blackwood
1997-2003 Windstar 2003-2005 Aviator
1997-2007 E-Series, Expedition, Explorer, 2006-2007 Mark LT
F-150, F-53 Motorhome Chassis, MERCURY:
F-Super Duty, Ranger
1997-2002 Cougar, Mystique
2000-2005 Excursion
1997-2005 Sable
2001-2003 Explorer Sport
1997-2007 Grand Marquis
2001-2007 Escape, Explorer Sport Trac
2005-2007 Montego
2004 F-150 Heritage
2006-2007 Milan
2004-2007 Freestar
1997-2002 Villager
2005-2007 Escape Hybrid
1997-2007 Mountaineer
1999-2007 F-650, F-750
2005-2007 Mariner
2006-2007 Mariner Hybrid
This article supersedes TSB 01-15-6 to update the a. If leaks are found on the inlet (or outlet)
vehicle model years and Service Procedure. tubes entering /exiting the heater core, it is
most likely due to due to high flow rate -
ISSUE replace the heater core and install a
The majority of repeat heater core leaks are due to restrictor in the heater hose closest to the
high flow rate or use of poor quality coolant. engine block, reference Workshop Manual,
However, electrolysis should also be checked, Section 412.
especially when repeat repairs have occurred.
b. If leaks are found in the body of the heater
ACTION core itself, and does not appear to be the
If the heater core is leaking, review the location of result of physical damage like contact or
the leakage and check the condition of the coolant. puncture, check the coolant for possible
electrolysis.
SERVICE PROCEDURE
1. Review the location of the leakage and check
the condition of the coolant:
NOTE: The information in Technical Service Bulletins is intended for use by trained, professional technicians with the knowledge, tools, and equipment to do
the job properly and safely. It informs these technicians of conditions that may occur on some vehicles, or provides information that could assist in proper
vehicle service. The procedures should not be performed by “do-it-yourselfers”. Do not assume that a condition described affects your car or truck. Contact a
Ford, Lincoln, or Mercury dealership to determine whether the Bulletin applies to your vehicle. Warranty Policy and Extended Service Plan documentation
determine Warranty and/or Extended Service Plan coverage unless stated otherwise in the TSB article.The information in this Technical Service Bulletin
(TSB) was current at the time of printing. Ford Motor Company reserves the right to supercede this information with updates.The most recent information is
available through Ford Motor Company’s on-line technical resources.
Copyright ã 2006 Ford Motor Company Online Publication Date October 17, 2006 PAGE 1
TSB 06-21-19 (Continued)
Testing For Electrolysis c. Voltage less than or equal to 0.4 V on all
grounds OK.
Check for voltage in the cooling system by touching
the negative contact of a voltmeter to the battery d. Any one greater than 0.4 V, check and
ground or a known good ground and suspend the clean ground cable connections.
positive lead in the coolant, making sure it is in
contact with the coolant but not touching any metal e. Check accessories without using the on off
part of the radiator or cooling system. Both AC and switch on the vehicle instrument panel, use
DC voltages must be checked. Vehicles normally a jumper wire to ground.
have DC voltages; however, a faulty engine block f. Plug in engine block heater, if equipped,
heater or faulty diode in the alternator can produce and test.
AC voltages. It is understood that coolant is lost
due to heater core failure but try to obtain a voltage g. Recheck voltage less than or equal to 0.4
reading on the old coolant in the engine block V.
before addition to or replacement of. To keep more
coolant from exiting the heater core clamp off h. Unplug engine block heater, if equipped.
heater core lines and measure coolant in the engine 3. Check for loose, missing, or inadequate
block. Try not to dilute the original coolant with new grounds.
coolant during testing if possible.
a. Test with ground probe to battery ground,
1. Determine whether coolant condition is engine ground, and vehicle ground
acceptable. sequentially.
a. Remove both cables from the battery and b. Crank engine but do not start.
ensure they do not contact each other or
the vehicle. c. Monitor voltage while cranking. less than or
equal to 0.4 V OK
b. Touch negative lead of voltmeter to engine
ground and positive lead in the coolant. d. If greater than 0.4 V, ground or repair
starter.
NOTE
POSITIVE TEST PROBE IS IN THE COOLANT e. Start engine and run at about 2000 rpm.
FOR TESTING.
f. Turn on all accessories including those
c. Check the voltage in the cooling system. If customer only uses occasionally such as CB
less than or equal to 0.4 volts (V) OK, radio, cell phone, etc.
reconnect battery cables and proceed to
Step 2. g. Test with ground probe to battery ground,
engine ground, and vehicle ground
d. If greater than 0.4 V, flush cooling system sequentially.
thoroughly.
h. Voltage less than or equal to 0.4 V OK
e. Recheck voltage less than or equal to 0.4
V. i. If greater than 0.4 V, turn off one item at a
time until V drops to less than or equal to
f. Reconnect battery cables. 0.4 V. Repair ground to the accessory just
identified.
g. Refill the system with appropriate
Motorcraftâ engine coolant. j. Recheck voltage less than or equal to 0.4 V
2. Check for loose or missing grounds at static k. Turn the DVOM to AC volts.
conditions.
l. Check for ANY AC voltage greater than 0.4.
a. Turn off all accessories. Turn ignition on but
do not start engine. m. If any AC voltage is present then try turning
off each accessory one at a time including
b. Test with ground probe to battery ground, blower motor and any fan motors.
engine ground, and vehicle ground
sequentially.
PAGE 2
TSB 06-21-19 (Continued)
n. If AC voltage is still present then shut 4. Refill the engine cooling system, reference
engine off and remove B+ from the Workshop Manual, Section 303-03.
alternator and tape it up then retest.
NOTE
o. If voltage drop is gradual to less than or IF THE HEAT OUTPUT IS INSUFFICIENT, OR
equal to 0.4 V, the ground straps may THE ENGINE DOES NOT REACH NORMAL
simply be overloaded by added accessories. OPERATING TEMPERATURES, VERIFY PROPER
Test by using heavy gauge jumper to THERMOSTAT OPERATION AND REPEAT
ground. If indicated, install heavier gauge PROCEDURE IF REQUIRED.
ground strap(s) and recheck.
WARRANTY STATUS: Eligible Under Provisions Of
NOTE New Vehicle Limited
If vehicle is equipped with electric cooling fans, be Warranty Coverage
sure they cycle during this testing and monitor DEALER CODING
voltage when they are on and when off. CONDITION
BASIC PART NO. CODE
CAUTION 18476 42
DO NOT GROUND HEATER CORE. IF THE
HEATER CORE IS GROUNDED, YOU HAVE
PROVIDED THE ELECTROLOSIS A PATH
THROUGH THE HEATER CORE. THIS WOULD
CAUSE THE HEATER CORE TO BECOME AN
ANODE OR RECEIVER AND IT WOULD
PROMOTE THE ELECTROLOSIS, OR ANY
STRAY VOLTAGE TO USE THE COOLANT AS

 

Update:
I took the vehicle to another shop to recheck for blown head gasket or electrolysis. They could find no sign of either. Voltage max was .2V which was less than the 0.4V in the TSB. They also did a good flush. The voltage after this was less than 0.1V both A/C and D/C. When we did the check while cranking the engine with the starter it was about 0.2V.

They did say the radiator had USA imprinted on it but I'm still wondering if I should just bite the bullet and replace it with an OEM radiator which would hopefully be better quality.

Any other suggestions?

 

Did it say made in..., assembled in..., originated in..., or anything else along with USA?

 

Apparently not. Mech said all he could find was a USA stamp on part of the aluminum near the plastic tank. I suspect though that the radiator was of very cheap quality.

 

I would think if it were electrolysis it should have taken out the new heater core along with one of those radiators.

The first heater core lasted 13 years and 230k you cant complain to much about that. You got your moneys worth on that one. Not electrolysis just age and ware and tear here.

I have got to agree with Alloro on this one . Just a bad bunch of radiators. Try another brand or supplier.