A coolant leak may develop from the radiator. Ford has released and updated radiator and powertrain control module (PCM) software update to address this issue. The software update includes revised cooling fan operating parameters. Failure to complete both service procedures may result in repeated radiator failures.
Coolant Leak/Overheating Due to Radiator Leak on Mercury Mountaineer
Average mileage: 124,904 (72,350–220,000)
Engines affected: 4.0L V6, 4.6L V8
21 people reported this problem
2006 Mercury Mountaineer - 4.6L V8 135,000 mi, Visitor
Radiator replaced October 2014 August 2015 new radiator started leaking same as other radiator at this time has not been repaired waiting to see to make sure I can get the problem fixed permanently this time
2006 Mercury Mountaineer - 4.0L V6 97,000 mi, Visitor
Antifreeze leak at lower left (driver side)bottom of fin tubes. I had replaced the radiator with a new radiator from NAPA. Need to have Ford re-program the PCM with a new fan strategy. Check Ford's TSB09-8-1.
2003 Mercury Mountaineer - 4.0L V6 120,000 mi, Visitor
Haven't fixed it, just found out.
2006 Mercury Mountaineer - 4.0L V6 144,000 mi, Visitor
I am now on my 3rd radiator for this vehicle. The first radiator failed within 4 yrs of the car's life and the second 3 yrs later. Each time I had to replace the radiator. I did not go to the dealership because they wanted close to $1000 to replace the radiator.
2006 Mercury Mountaineer - 4.6L V8 77,000 mi, Visitor
My radiator is leaking from the seam too so I have been investigating this problem to some level of detail. Firestone checked the problem (for a fee) and was told by the OEM provider of the new radiator about a Service Bulletin on the problem. The service bulletin ONLY lists the 4.0L engine but the OEM insisted that it applies to the 4.6L too. Paid money (again!) to my local Ford dealer who I thought would find the problem and the bulletin and hopefully repair it under warranty or some other provision. Bottom line ... the Ford dealer shows no record of the 4.6L having this problem and is confused by what the OEM is saying. Firestone trusts this OEM who insists that the problem is well known and reprogramming is required. Too bad ... who to believe? I just paid Firestone to do the repairs ... need my car. Told Firestone to flash the computer with the upgrade if it showed necessary. Why take the risk? But very disappointed in Ford to be honest. This appears to be a well-known problem (OEM said it popped right up on his computer when the part number was entered) that is fixed by a software upgrade to what sounds like an initial design flaw. But Ford disavows any knowledge of the problem for the 4.6L. Ogden Lincoln Mercury in Westmont, IL is the dealer by the way.
2006 Mercury Mountaineer - 4.0L V6 143,000 mi, Visitor
Yesterday I had the third new radiator installed in my Mountaineer. My dear brother found this service bulletin which I will take to the local Ford dealer. Just hoping the fix doesn't cost more than a fourth radiator.
1998 Mercury Mountaineer - 4.6L V8 220,000 mi, Visitor
I have alot of water comining out of bottom of engine
2006 Mercury Mountaineer - 4.6L V8 95,000 mi, Visitor
After replacing the radiator at a dealership, and putting on new hoses, the car still is overheating. I've been back to the dealership 4 separate times....they seen confused about what's causing the problem. What should I ask them to try....reprogramnming the PCM ? Appreciate any insight you could give me.
2006 Mercury Mountaineer - 4.6L V8
2003 Mercury Mountaineer - 4.0L V6 136,899 mi, Visitor
The car keeps over heating at different times
I just had to replace mine do to this and we were an hour away from home with my daughter in the car
2007 Mercury Mountaineer - 4.6L V8 114,050 mi, Visitor
where is the TSB at on this
2003 Mercury Mountaineer - 4.6L V8 120,000 mi, Visitor
goin on the 3rd radator
2006 Mercury Mountaineer - 4.6L V8 101,000 mi, Visitor
I am working on my 3rd radiator........
2006 Mercury Mountaineer - 4.6L V8 72,350 mi, Visitor
Radiator just started leaking like crazy. Dealer said there was a "crack in the seam". No mention made of the PCM update. Had to replace the radiator.