02 explorer 4.0 by coolant issue

[Apexmaster]

Hello
I recently acquired 2002 explorer 4.0l v6 xlt with 140k on the clock. The lady did not want to fix it so she gifted to me. It has an issue I see coolant in the motor?.
Brief search showed the plastic intake manifold is known to leak.
This lady has maintain the vehicle. I can see new alternator, belt, plugs , wires, air filter.
She was told the head gasket is blown.
When I start the SUV, it starts right up revs fine. I don't see any coolant out exhaust pipe .
How can I verify it's a head gasket or just intake manifold?
Thank you
Happy holidays

 

[shucker1]

Coolant in the oil is not a good sign.

I would go for a compression check first.

 

[Apexmaster]

what psi should i be looking for i have a compression tester tool. i will post pic and a brief video of engine oil dipstick tomorrow. her coolant is green and the oil looks brown but little runny,. it might be light weight? also I was told to look at the engine oil fill cap. if it has coolant leak you would see residue on the inside of the cap.
i found several videos showing different methods to identify a bad head gasket. if coolant is leaking on compression stroke or power, it would show in the radiator. By having a lot of bubbles and coolant flowing out while you have radiator cap removed and engine running. if you have a coolant leak on the exhaust stroke, it would be coming out of the exhaust. White smoke that is. here one of the video I found.
watch entire video. he gives explanation for different stages on different times of the video. like interesting parts start at 3min mark to end.

 

[Apexmaster]

hello
here are few pictures of the SUV, and brief Video of me doing Block test. Please excuse my English.
I got this SUV for Free from a Co worker. another co worker told her she needs a head gasket. I drive the SUV home from work 22miles. the coolant level remained same. There no loss in power nor smell. Only noticeable issue is a vibration coming from somewhere under the driver seat. once I got on the freeway and hit 60 mph I can really feel this vibration. Not sure what it is. the lady stated it started doing this several months ago. otherwise heat works, front and rear, wipers, it does go into 4x4 High, and Lo. The engine never went above half way on the gauge. As you can see another issue is rear trunk door lock. There is a lot of water. I did read this is common issue, but i did not find anywhere how to fix this issue.
the block test:
i performed it 5 times. When engine was cold, and when engine reached operating temp. All 5 times the fluid remained Blue to slight blue, but never turned yellow as seen on other videos of bad head gaskets.

https://drive.google.com/open?id=1mvxGvXBg0GJB3zYZIwBB3qZ7nLZfr6Bh