Ford Explorer Problems

Plastic Intake Manifold May Crack Causing Coolant Leak on Ford Explorer

Problem Description and Possible Solution

The 1997-2001 Ford Explorer V8 with a 100% plastic intake manifold  is known for engine overheating, even with normal use, and a coolant leak from the front of the manifold. This will often trigger the check engine light and low engine coolant warning light.

The engine coolant leak is from a factory defect, which causes cracking on the front coolant passage of the intake manifold. In a very short time, this leak will lead to engine overheating issues, especially while the vehicle is idling.   

Between 1999 and 2001, Ford released an updated version of this engine, known as the 'PI' version with a metal coolant passage on the front of the intake manifold, to prevent future issues.

There is no factory authorized repair for the intake manifold, and replacement is required to correct the engine coolant leak and overheating issues.


(218 people reported this problem)

Ford Explorer Vehicles With This Problem

RepairPal Verified
Average mileage: 123,674 (10,000–235,000)
Engines affected: 4.0L V6, 4.0L V6 SOHC, 4.6L V8, 5.0L V8
15 model years affected: 1995, 1997, 1998, 1999, more2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
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Viewing 1-20 of 82 comments
Water leaking from top piece of thermostat..& coolant jug keeps emptying cant hold water for a day..please help im not a mechanic...
leaking coolant not going to the oil or on the ground but you can smell it when turn your car off
My 2006 Ford Explorer is leaking anti freeze on to my engine. The leak is coming out of a pice that I guess was sealed and now is not. How do I fix this?
Just got my 2008 Explorer back from the Ford Dealership for routine LOF and overall inspection. Was told I need a new upper thermostat housing ($375 including labor) and a new radiator ($655 including labor) because of leaks. My research indicates the former causes the latter. I never saw coolant on the garage floor. This appears to be a common problem and would appreciate Ford taking responsibility for installing a PLASTIC housing in an area that produces much heat. Cheap part for Ford, but very expensive to replace for their loyal customers.
my plastic piece cracked on the thermostat housing causing a coolant leak..and the problem has not been fixed yet..i need some money 2 help gettn it fixed because u have 2 replace the whole intake..
Just noticed small amount of coolant sitting on the block. PLASTIC thermostat housing looks to be the source, seems to be above the intake. T-stat housing looks pretty easy to yank, pretty straight forward. Reading all the comments a pattern becomes very clear, FORD MOTOR COMPANY F$&ked up on this design and they've been sending that cheap crap out the door for at least 8 years. Everyone has the same issue from 02-09, and that's just what I've seen researching for 5 mins. Anyway, I'm gonna tear it out on my next day off, I'll let you know. Recall please!!! You cheap bastards...
My Explorer overheated out of the blue one day. I filled it with coolant and when leaving for work the next day I noticed fluid that had leaked onto the ground.
When my mechanic checked it out he said it was coming from the Intake Manifold area and it was the gasket.
I bought a new gasket.
When my mechanic got into the intake manifold he found out that part of the plastic was broken off. He put the gasket on and sealed it.
After letting it sit a couple of days we started it up and it was STILL leaking.
I have been without my vehicle now for 2 months because I don't know what to do!!!!
The parts associate at the dealership where I purchased the new gasket said that there was a lawsuit regarding this problem but it only covered vehicles through 2001 and for a recall settlement we would have to get a new lawsuit started for vehicles 2002 and newer!!!
Problem: coolant leak from plastic thermostat housing, coolant seeping from center where two plastic halves are pressed together.
Solution: replaced housing (no way to repair plastic)
Water is coming out between the transmission and oil pan, not sure what problem is, any answer would be a help
Coolant leaking from plastic thermostat housing. Bought new one for 67$ took 1/2 hour to change. 5/16 socket and ratchet and a pair of channel locks. Quit your crying.
Plastic thermostat housing leaking. Ford wants hundreds of dollars to replace it. So many problems with the 2002 Ford Explorers. Why would Ford use plastic!! Very angry.
Have had a coolant leak problem for over a year and the local Ford dealership was no help. All they wanted to do is leave the car with them for a few hours and maybe they could figure it out. Well don't have that kind of time or money since the car is no longer under warranty. Well at first thought water pump went out only to find out it was the thermostat housing has been the problem. If the local dealership was more helpful and if formed I would be out over $300 in cost so far. I really feel like Ford and their dealerships have let me down as a consumer of their products
During an oil change the tech had to add approx 1 gallon of coolant. This prompted him to look for a leak. Knowing this was weak point he went straight to the problem, a cracked thermostat housing.
Bought a 2008 Explorer Sport-Trac in August of 2014. Was under the hood a couple of months ago, and noticed something resembling packing material sitting in the manifold area. Grabbed it with pliers and it turned out to be a wad of paper towel and trash. Talked to my mechanic, and we decided that the previous owner knew something was leaking a little. We talked about the fact that it was a known problem with the 4.0 engine. Decided to just wait and see. Flash forward to last Friday, and my Sport-Trac overheated on the way to work. Thermostat housing cracked. Bought part from Rock Auto -- Dorman, new and improved, over the MotorCraft part. Issue solved. $47 for the part, and $65 for labor.
My 2004 Eddie bower edition v8 explorer just all of a sudden overheated no warning thought it was upper house turns out a cracked intake you would think when you spend almost 40 thousand on a vehicle and the company knows its a problem they knew about they would fix it by recall since its not only a few trucks but the majority of them I believe when I have this fixed it will be sold and I will never purchase another ford again !!!!!!! Its bad when imports are more dependable than American Mar vehicles. My next purchase will be a Toyota truck at least they are better built than ford
The check engine light kept coming on, I would take it in they would clear it and within days it would come back on again. Last week the heater stopped working and the check engine light was on again. My mechanic told me that there was no coolant, the radiator was half full and that the engine was running to lean. He said this all stemmed from the plastic intake manifold and gasket failing. If I wouldn't have taken it in because of the heater, I would have done some major damage to my truck. I found out that some 1997 Ford Explorers have an aluminum intake manifold and some were plastic, apparently I got the cheap plastic one. Merry Christmas to me, $500.00 and it will be fixed...........Thanks Ford :(