Spark plug well wet, water or coolant?

[Mr.cant-find-his-10.5-mm]

Vehicle is a 07 Ford Ranger with the 2.3L DOHC at around 100k km. Similar engine to Ford Fusion, Escapes, etc.

Long story short a couple of weeks ago I was tracking a sudden misfire that occurs when the vehicle is in storage. It turns out to be a spark plug boot pops off the plug by itself on cylinder # 3. When I remove the boot I notice there are some water droplets in the spark plug well. Spark plug boot was also covered in rust-like goo, but came off pretty easy with some electrical connector cleaner. I have attached some pictures below.

I did hose down the engine bay last summer so some water might have slipped inside due to a bad boot seal. But I've been driving this truck hard since then and never had a problem with it. I'm starting to think I might have a internal coolant leak that happens while the vehicle is in storage.

Now my question is, is this just water or do I have a possible coolant leak? It's really hard to tell because the coolant is also yellow in color. And how can I clean the "rust" off the spark plug well? Can I reuse the boot just by cleaning it off?

Thanks in advance! Just want a good night's sleep...

 

[Jethro_Bob]

If it was leaking there it would be full of oil. My advice is to check and make sure all plugs are clean and dry. The placement of the oil fill tube makes it easy for spilled oil to into plugholes 3 and 4 (also 2 if someone makes a total mess of it). So if it's your first time checking, don't assume the worst until you verify a leak.

 

[Kira]

That stuff looks well baked. As above, you gotta see what's going on.
A thorough cleaning is what you want to do first.
I'd reuse the boots if they look like they'd do their job after cleaning. If they're all brittle and crumbling, no.

 

[BrentB]

The boot "popping off by itself" is a good clue - water leak from the hose down that then goes to steam when hot. Probably not a leak from the engine.

 

[ammolab]

Is the plug "rusty"...must be from your engine rinse hose water as coolant should have rust inhibitors.

The rust isn't from an aluminum cam cover.

 

[Mr.cant-find-his-10.5-mm]

Originally Posted by Jethro_Bob
If it was leaking there it would be full of oil. My advice is to check and make sure all plugs are clean and dry. The placement of the oil fill tube makes it easy for spilled oil to into plugholes 3 and 4 (also 2 if someone makes a total mess of it). So if it's your first time checking, don't assume the worst until you verify a leak.



#1 is clean. I haven't check #2 and #4 yet, they are pretty snug down there. I'll have to wait until the weather is a bit warmer. (still @ -15C!)

#2 and #3 shares the same well but I'm surprise #3 is the only troublemaker.



Originally Posted by BrentB
The boot "popping off by itself" is a good clue - water leak from the hose down that then goes to steam when hot. Probably not a leak from the engine.


Originally Posted by ammolab
Is the plug "rusty"...must be from your engine rinse hose water as coolant should have rust inhibitors.

The rust isn't from an aluminum cam cover.



Yes the plug seems a bit rusty. It makes way more sense now. That sure makes me sleep a lot better tonight!!

 

[spk2000]

Originally Posted by ammolab
Is the plug "rusty"...must be from your engine rinse hose water as coolant should have rust inhibitors.

The rust isn't from an aluminum cam cover.


Agreed here coolant would likely not rust like you are seeing. Rust inhibitors and ethylene or propylene glycol would be gummy not rusty