4.0 OHV Top Dead Center questions.

[Eddo Rogue]

I did my cam synchro a few years ago...twice.

Second time was because I have a weird year that uses a discontinued synchro, so I had to install an aftermarket unit, which did not last very long. Luckily I tracked down a NOS Motorcraft unit on fleabay.

I found a tech article here at TRS and followed it exactly.
I did the tape thing, but had no need for the alignment tool.
I eyeballed it to make sure it was pointing the way it did in the article.

I noticed the tricky part is it another 1/4-1/2 turn as it drops in.

The 2nd time I was able to do it without removing the intake, but probably wouldn't be able to again lol.

Still squeaks for a bit once in a while, but I'm living with with it.

 

[seanagins]

Was radiator cap off?
Cracked head or blown head gasket will show at rad cap, coolant will start to come out once pressure is applied to leaking cylinder

4.0l OHV's were prone to cracked heads if overheated even one time

Ring leakage of 16% would not be a big deal on a leak down
Metal on metal NEVER has a good seal for air
And the rings have the most surface area to seal

Compression test is better test for air seal on the rings, since piston/rings are moving fast so only need to hold the compressing air for a split second, and in your test its above 150psi so had to hold a higher pressure than leak down pressure

Leak down is generally to see if its valves(and which one) that is leaking, or cracked head or blown gasket

I am back to trying to find TDC for cylinder number 1 so I can perform a cylinder leak down test. Is there a surefire way of knowing that both valves are closed when the piston for cylinder number 1 is up on a stroke for TDC?

 

[Eddo Rogue]

I am back to trying to find TDC for cylinder number 1 so I can perform a cylinder leak down test. Is there a surefire way of knowing that both valves are closed when the piston for cylinder number 1 is up on a stroke for TDC?

Valve cover off, thumb over spark plug hole or wooden bbq skewer stick down it...
turn the motor until you feel air push in thumb or skewer wont go up anymore (and both valves are closed)

 

[seanagins]

Valve cover off, thumb over spark plug hole or wooden bbq skewer stick down it...
turn the motor until you feel air push in thumb or skewer wont go up anymore (and both valves are closed)

Is there a write up for the procedure of valve cover(s) removal for 1997 Ford Ranger 4.0 liter OHV engine?