Hello everyone just picked up a 2008 Explorer Limited , well optioned , tow package.

[Motorhead440]

The explorer has 133k miles . Seems to be consuming coolant through #8 cylinder. Oil is clear , but I have the occasional bubble in the radiator and a wet #8 plug. Thinking of pulling the head and replacing the gasket unless these also have plastic intake issues ? Thoughts? Thanks !

 

[Fix4Dirt]

welcome to EF!!!! i would suspect something head related, but lets see what others think, i dont own a 4th gen. hope ya get your answers!!!!

 

[Motorhead440]

welcome to EF!!!! i would suspect something head related, but lets see what others think, i dont own a 4th gen. hope ya get your answers!!!!

Thanks ! If it is the head, is it common to just pull the head without pulling the motor? Seems straightforward and easy to me. Anything that prevents this?

 

[Fix4Dirt]

Thanks ! If it is the head, is it common to just pull the head without pulling the motor? Seems straightforward and easy to me. Anything that prevents this?

ill be honest, dont know my sohc at least i cn pull one, not the other. not sure though about the 4G, however.

 

[Motorhead440]

ill be honest, dont know my sohc at least i cn pull one, not the other. not sure though about the 4G, however.

I recently did lifters on a 2016 Ram drivers side. I have to say , it beat me up pretty bad but I won in the end. The Ram allowed for leaving the exhaust manifold on and it seems I can do the same on the 4.6. This makes life easier.

 

[Fix4Dirt]

hope it all works out for you! sorry i cant be of more help, my experience lies 95% in the 2nd gen

 

[Mike65]

Welcome.

 

[beepinX]

Welcome! Lots of helpful folks around

 

[BrooklynBay]

Welcome to this forum! Was there an over heating issue which caused the leak?

 

[Motorhead440]

Welcome to this forum! Was there an over heating issue which caused the leak?

It was given to me by an elderly family member who recently passed. It had been sitting for the last year or so. I have its original window sticker. There are no outward signs of any overheating that I can tell. Engine has 133k runs smooth and no codes. No visible leaks or corrosion from any hoses or thermostat housing or the radiator. I park it on cardboard for days, nothing observed. Underside of the vehicle is incredibly clean and no antifreeze smell anywhere. No bubbles in the radiator and the "Block Check" test kit shows no exhaust gas in the radiator. No coolant in the oil. Transmission is showing no indications that its fluid is contaminated.. New Thermostat and 20 psi cap. It seems to use a quart plus every 400 miles. No visible smoke.

Here is the best clue I have : While troubleshooting a slight miss, I put all new plugs and coil packs. When I pulled #8 Cylinder spark plug it was fouled and seemed wet with what appears to be antifreeze.

I am not ruling out a blown head gasket however, does this intake have coolant flowing though it? If so. What's the possibility that a leak has developed between the coolant passage in the plastic intake and #8 intake runner and coolant is entering the #8 intake runner via cracked plastic? I do not need to drive the car. My intent is to repair it and have a spare vehicle or repair and restore it to as new as I can get it and give it back to my cousins widow if she want it. I am mechanical . As a hobby, I've built performance engines and transmissions for Ford FE's, Windsors, Clevelands, Modified, 385 series and several 5.0 Mustangs, all Mopars , all Chevy , Buick turbo V6's , etc. But guess what I've never touched? Yup a 4.6 3v modmotor !

 

[Josh P]

I'd pull the manifold first and inspect. If nothing wrong then pull the head, it could be a gasket or a hairline crack in the head.

 

[Motorhead440]

I'd pull the manifold first and inspect. If nothing wrong then pull the head, it could be a gasket or a hairline crack in the head.

Thanks for the reply.

Yeah , thats what I'm thinking. My intake does not look like that one. I kinda' wish it did as you can see the coolant o ring next to #8. I suspect this intake has no coolant passages in the rear. But what do I know. What would be awesome is the remote possibility that someone else chimes in and says "I had the exact same symptoms and it turned out to be xxxxxxxxx. " . I guess it's still coming apart , one way or another.

 

[Motorhead440]

Took a look at the plugs today and did compression checks again.. Top to bottom # 8 165 psi ; #7 165 psi ; #6 180 psi; #5 180 psi. Runs great , just consuming coolant.

 

[sandsprayer]

Welcome!
My 1st gen had a slight freeze plug leak. I spent more than a few times trying to chase down the problem.
Then 1 day I saw the smallest rust stain to the rear of the plug, sure enough that was it.
It didn't stain the motor ,tranny, underside.
Just enough for a gallon every 500 miles or so

 

[D Hook]

Isn't it true that if you have coolant leaking into the cylider the plug for that cylinder will look cleaner than the others from being steam-cleaned on each combustion stroke?

I would suspect the radiator first since those have a history of failure on these models. Be sure to look on the motor-side of the radiator fins. There was someone here on the board who had the same issue as you and finally found the leak on the inside fins of the radiator. Also, you might want to try changing out your 20# radiator cap for a 16# instead. There's quite a few of us that have done that to reduce pressure on the radiator and other coolant components. Do a search and you should find the part number on this forum. Or have them give you one for a 2005 model. Those were 16# also. Keep your 20# in the console just in case. I've finally took mine out of the console after 2 years of running the 16# with no problems.

Found it on another thread: Stant 10233 16 psi cap.

Or a Motorcraft comparable would be good too. Stay away from the china crap. I put on a motorcraft I bought at O'Reilley's or Napa, don't recall which. But you have to give them a part number because if you ask them for a cap for a 2006 Explorer V-8, they'll give you the 20# and say that's the only one they carry for your vehicle. Or, like I said earlier, ask them for one for a 2005 Explorer instead.

 

[Motorhead440]

Welcome!
My 1st gen had a slight freeze plug leak. I spent more than a few times trying to chase down the problem.
Then 1 day I saw the smallest rust stain to the rear of the plug, sure enough that was it.
It didn't stain the motor ,tranny, underside.
Just enough for a gallon every 500 miles or so

Hey thanks . Great experienced suggestion. I'll inspect tomorrow.

 

[Motorhead440]

Isn't it true that if you have coolant leaking into the cylider the plug for that cylinder will look cleaner than the others from being steam-cleaned on each combustion stroke?

I would suspect the radiator first since those have a history of failure on these models. Be sure to look on the motor-side of the radiator fins. There was someone here on the board who had the same issue as you and finally found the leak on the inside fins of the radiator. Also, you might want to try changing out your 20# radiator cap for a 16# instead. There's quite a few of us that have done that to reduce pressure on the radiator and other coolant components. Do a search and you should find the part number on this forum. Or have them give you one for a 2005 model. Those were 16# also. Keep your 20# in the console just in case. I've finally took mine out of the console after 2 years of running the 16# with no problems.

Found it on another thread: Stant 10233 16 psi cap.

Or a Motorcraft comparable would be good too. Stay away from the china crap. I put on a motorcraft I bought at O'Reilley's or Napa, don't recall which. But you have to give them a part number because if you ask them for a cap for a 2006 Explorer V-8, they'll give you the 20# and say that's the only one they carry for your vehicle. Or, like I said earlier, ask them for one for a 2005 Explorer instead.

I really appreciate the experienced suggestions. This is exactly what I am looking for. I swapped to a 16# Motorad cap yesterday. While I had the plugs out today I put an android based endoscope inside each bore and took video and pictures. As you noted, i expected to see one nice clean piston top in either #7 or #8 . That wasn't the case. They all looked like 133k mile piston tops.

Thanks !

 

[94Eddie]

Have you checked for combustion gases in the coolant? You can get a kit to do this for cheap at auto parts stores. If the test shows combustion gases are present in the coolant then you have a head gasket issue. Also, I second replacing the 20 psi radiator cap with a 16 psi part. IMO, one of the main reasons the radiators fail in these vehicles is due to the 20 psi pressure they run. I have been using a 16 psi cap since the beginning of the year without a single issue. The temperature gauge has never moved beyond the point the 20 psi cap held. If you want to go with a Motorcraft cap this is the one you want: Motorcraft RS76 Radiator Cap.

 

[admsbmr]

Remember if you pull the head that would be the best time to out in new studs for the exhaust manifold as they are prone to breaking.

 

[94Eddie]

Remember if you pull the head that would be the best time to out in new studs for the exhaust manifold as they are prone to breaking.

....and replace them with the Motorcraft stainless steel stud kit.