I own a 2007 F150 with the 4.6l V8, I had a problem out of no where the truck started to shake and the CEL flashed for a while then stayed on, took it to my mechanic and he found antifreeze in the #8 spark plug well. He blew it out , pressurized the coolant system, and found no leaks stuck the camera in the cylinder, no water. Put her back in CEL went off and she ran like new. 2 days later the same thing, Im not losing coolant and it hasn't rained or any thing. Any idea of where the coolant is comeing from?

Any help is greatly appreciated.

Thanks

 

Do the heater hoses run anywhere near #8?

 

If the heater hose is leaking a little you might not notice any coolant going down till after a week or so and a pressure test wouldn't show it. I think that could be where it is coming from.

 

Has to be getting in from above. I thought the heater hose was above 3&4 sure he has the right number on the cylinder? 8 is on the left side..

 

Yes it was #8 he had the code reader on it, it was a miss fire in #8 last one back on the drivers side. Oddly it has gone away for now, I will keep a eye on the fluid level, I think the heater hoses run on the other side the of the engine, but I might be wrong.

Thanks for the help.

 

They run on the passenger side

 

I had a cracked intake one time and it was doing that. But is was so small that I never seemed to loose any coolant but it filled my plug hole up and shorted my coil pack. After it did it twice we realized there was a very very small crack in the plastic intake which is common on these