Compression test 01 Navigator

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

stamp11127

Full Access Members
Joined
Mar 10, 2012
Posts
6,218
Reaction score
1,250
Location
Temple, Georgia
Here is an old mechanics diagnostic trick. There is a fitting that allows you to put compressed air into the cylinder so you will need that and a source of compressed air. Shoot high pressure air into the cylinder and have a listen:

Bring the #8 cyl to tdc on the compression stroke. You can tell that by the direction the cam lobes are pointing for that cylinder. Both will be pointing away from the engine.
If you hear air leaking in the intake it is an intake valve, air out of the exhaust pipe - exhaust valve, air out of the oil fill cap - 1/2 keg of beer because you are tearing into the engine or replacing it.

Should you decide to tear into the engine...I'm going to assume it will be your first one. Is that correct? If so you will need a few tools that most diy'ers don't usually have.
1) Quality torque wrench (200-250ft/lbs) and maybe torque angle gauge
2) 1/2 drive socket set
3) good sized combo wrenches
4) air impacts would be really nice

Just to name a few....

Does yours have the dual overhead cams? If so add #5 to the above - a kegenator
 
Last edited:

Atman246

Full Access Members
Joined
Feb 11, 2017
Posts
76
Reaction score
40
Location
Ontario,Canada
Hey Fordgirl,looks like you're pulling the valve cover. You could do the leakdown test as Stamp suggests,but you'll still end up pulling the valve cover. This could actually be good news because if it's as I suspect,you probably have a broken valve spring. This means the valve is hanging open,hence no compression. If that is the case,it'll just be a matter of replacing the spring. Keep us updated.
 
OP
OP
Fordgirl01

Fordgirl01

Full Access Members
Joined
Aug 1, 2016
Posts
293
Reaction score
57
Location
St Lawrence County
Here is an old mechanics diagnostic trick. There is a fitting that allows you to put compressed air into the cylinder so you will need that and a source of compressed air. Shoot high pressure air into the cylinder and have a listen:

Bring the #8 cyl to tdc on the compression stroke. You can tell that by the direction the cam lobes are pointing for that cylinder. Both will be pointing away from the engine.
If you hear air leaking in the intake it is an intake valve, air out of the exhaust pipe - exhaust valve, air out of the oil fill cap - 1/2 keg of beer because you are tearing into the engine or replacing it.

Should you decide to tear into the engine...I'm going to assume it will be your first one. Is that correct? If so you will need a few tools that most diy'ers don't usually have.
1) Quality torque wrench (200-250ft/lbs) and maybe torque angle gauge
2) 1/2 drive socket set
3) good sized combo wrenches
4) air impacts would be really nice

Just to name a few....

Does yours have the dual overhead cams? If so add #5 to the above - a kegenator

It will be my first venture into anything past plugs and coils as far as engine work! I do like beer......I’ll keep plenty on hand-thanks for that tip!![emoji16]
I have lots of tools including 1/2” drive and even 3/4” (those impressive 3/4 inch were compliments of my grandfather’s shop-my dad gave them to me). I have 2 (1/2”) 22v cordless impacts (the big one and the compact one). I could probably add to my combo wrench assortment as I don’t have too many big ones. I also need to get a better torque wrench-mine is a POS!!

I believe it is a DOHC-why not make it more interesting-right?! 32v InTech V8 is what the tailgate says.


Sent from my iPhone using Tapatalk
 

1955moose

Full Access Members
Joined
Nov 23, 2014
Posts
5,981
Reaction score
1,338
I realized after my last post that yours is the 32 valve Lincoln motor. My CD won't help with the cam timing, but I'm sure you can get that part online and print it. Your 04 CD should work for a lot of the specs and other stuff. Just remember to bag and label the small parts. Use Ford parts if still available. If it does turn out to be a broken spring or valve, you most likely will have to pull intake and that head. We had a guy a few months back trying to do his 2 valve Expedition on the car, but couldn't get any tool in there. Do you have a machine shop that can redo your heads? We're all curious what happened.

Sent from my N9131 using Tapatalk
 

stamp11127

Full Access Members
Joined
Mar 10, 2012
Posts
6,218
Reaction score
1,250
Location
Temple, Georgia
Oh man, 32v! That will teach you the correct use of all four letter words to say the least.

If it isn't the valve spring make sure you follow the Ford service manual on removing the heads. Do not reuse TTY bolts - they will fail if torqued to the limit a second time.

Post a pic of the passenger side head in relation to the ac components back by the firewall. From what I remember there isn't any room on that side to lift the head straight up and out.

As far as getting into engine work, nothing like jumping in with both feet on a 32v!
 

stamp11127

Full Access Members
Joined
Mar 10, 2012
Posts
6,218
Reaction score
1,250
Location
Temple, Georgia
When you pull the valve cover, should the springs not be the problem you have to pull the engine. I looked at the factory service manual and head removal is not listed in the engine section of "in vehicle repair".

"Good news" is that with a special tool to hook the hoist onto, down in the valley, the engine will come up out of the engine bay.

I would say if you have to go this route to have access to someone that has done this before or give yourself plenty of time to ask questions before forcing/breaking things. Plus being in the Northern US you have the rusted bolts to deal with.

Not trying to scare you, just getting everything out on the table to avoid the "surprises" should you get into it.
 
Last edited:
OP
OP
Fordgirl01

Fordgirl01

Full Access Members
Joined
Aug 1, 2016
Posts
293
Reaction score
57
Location
St Lawrence County
Well if it comes to pulling the engine, I think I would admit defeat and have someone else do it. Luckily no rust on this one-it came from Arizona. That’s why I took a risk and grabbed it even though I knew it probably had some major issues (plus I prefer the 1st gen models).

I am well versed in 4 letter words, so it sounds like I’ll be making good use of my vocabulary!

This will be a long process as I rarely have a full day to tinker out in the garage but I will keep you posted as I take baby steps!!


Sent from my iPhone using Tapatalk
 
OP
OP
Fordgirl01

Fordgirl01

Full Access Members
Joined
Aug 1, 2016
Posts
293
Reaction score
57
Location
St Lawrence County
I realized after my last post that yours is the 32 valve Lincoln motor. My CD won't help with the cam timing, but I'm sure you can get that part online and print it. Your 04 CD should work for a lot of the specs and other stuff. Just remember to bag and label the small parts. Use Ford parts if still available. If it does turn out to be a broken spring or valve, you most likely will have to pull intake and that head. We had a guy a few months back trying to do his 2 valve Expedition on the car, but couldn't get any tool in there. Do you have a machine shop that can redo your heads? We're all curious what happened.

Sent from my N9131 using Tapatalk

I do know an excellent machine shop if I should need one.


Sent from my iPhone using Tapatalk
 

stamp11127

Full Access Members
Joined
Mar 10, 2012
Posts
6,218
Reaction score
1,250
Location
Temple, Georgia
It's nothing but a bunch of bolts and nuts....if you have the needed tools, pulling and engine is no big deal. You just need to work organized and methodical. The big thing is having the correct tools.
There are a few tools in my tool box I've only used once. But having them made the difference. There are also a few that I've made after I saw the cost of the commercial version.
 

TobyU

Full Access Members
Joined
Apr 5, 2013
Posts
2,479
Reaction score
869
Location
Ohio
The needle jumped up every time the engine cranked over until it appeared to reach a max number (except for #8 which did not move the needle at all). I cranked it over maybe 8-10 times for each cylinder.

Then it should have either been smoking very badly out the tailpipe for making lots of popping or noises when it was running.
If one has zero compression and it doesn't jump up and down then it either has a hole burn in the piston or one of the valves is completely open. I guess if the exhaust valve was the one that's open it would run decently and not pop where you can hear it. It would be popping out the exhaust and the muffler so it wouldn't be that noisy.

Sent from my iPhone using Tapatalk
 
Top