4.0L Cylinder Head gasket job

Yet another head gasket job question.

I have a 2000 Ford Ranger 4.0L V6 with 110,000 miles on it. I have been smelling burned coolant for some time now and got busy trying to locate the source.

I did the glove test and no movement at all. I did a radiator pressure check and found it did NOT hold pressure. I found two of the sources for the leak. One place it was leaking is on the left front of the engine right below the exhaust manifold, I believe where the head mates with the block. While doing the pressure check I wiped this area dry and pressurized it again, the coolant started seeping out. It is also leaking on the left rear. I believe the right side is also leaking but figured I would do both sides so I didn't check the right side as thoroughly. There is no oil in the coolant and there is no water/coolant in the oil. I believe it's the head gaskets.

I also did a compression check:

1-140
2-145
3-140
4-130
5-150
6-155

My friend and I are considering doing it ourselves. He is an aircraft mechanic with quite a bit of car experience and has a shop with great tools. All I have is some common sense and some money. Ford wants about $3,000 to do the job and a private shop quoted around $1,800 to $2,000.

I believe we can do the job, but one concern I have is after reading the Ford manuals (I bought the original Ford repair manuals), and reading the Haynes manual, is the application of silicone. I understand there are several gaskets that need to be changed and come with the kit, (I'll buy the original Ford kit), but what I'm not clear about is the application of silicone/RTV. Where do I have to put it?

Any other input is appreciated.

Jeff

Have the heads checked and make sure the block is not warped with a level.

Glove test is pretty definitive, I would guess no leak from cylinder to cooling system, and if there is no "white smoke" on start up it would strengthen that guess.
And if overflow tank is not filling up to the top that would also indicate no cylinder leak.

I would check lower intake for coolant leak, it will leak down right where you describe.
Passenger side front where it meets the head and drivers side rear where it meets the head, these are both common leak points on the 4.0l OHV engine.
It runs down the edge between block and head and is seen under exhaust manifold.

This is the crossover for coolant from one head to the other thru the lower intake.
Because heads are iron and intake is aluminum the flowing coolant can cause electrolysis if coolant isn't changed every 2 years, and it eats away the gasket at those locations.

Head job
The RTV will go on the block at either end of the lower intake manifold, the intake gasket doesn't cover the ends of the intake, just the head ports and coolant ports, so RTV is used to seal the ends(flat surfaces) where intake is tightened down to block.

You can put RTV at the corners of the head gaskets to hold it in place but never found the need to do so if the dowels/inserts are still in the block.

Heads should be pressure tested and surfaced.
4.0l OHV has a weak casting between valve seats so if overheated a head will crack there.

With the head gasket kit you will get new valve stem seals, take those to the machine shop that is doing the heads, they will often install them for free, or if you have a valve spring compressor you can do it after heads come back from the shop.

You also need new head bolts, old ones can't be reused.

It is just wrench work so you can do it, take lots of pictures, label wires and hoses if in doubt.

I often take a running vehicle to local exhaust shop and tell them what I am doing, head job, then have them remove and reinstall exhaust manifold bolts and down pipe nuts, but snug not tight.
Most I ever paid for that was $60 and that was when they had to replace some bolts and nuts.
It can literally save you hours of messing around with a stuck or broken exhaust bolt/nut
It takes them less than a hour to do it, they have all the tools and tricks, and they have the spare parts on hand.


EDIT:
2000 will have Cam position sensor and synchronizer housing, rear top of the block.
This is timed to the Cam.
After you have the valve covers off(spark plugs out) you can rotate the crank to #1 Top Dead Center COMPRESSION stroke by watching #1 valves or feel for compression at #1 spark plug hole.
Line TDC mark up with 0deg
Remove Cam Position sensor and you will see the shaft under it take a picture of it's position and mark the housing.
Now you can remove the synchronizer, shaft rotates when pulled up because the gears are angled.
When reinstalling put engine back at #1 TDC compression stroke(there are TWO #1 TDC's that why compression stroke in important).
Then reinstall synchronizer so it looks like the picture you took.
It may not slide all the way down into the hole, that is because the lower part of the shaft also drives the oil pump, so it also has to mesh with that shaft, with synchronizer in place turn crank a 1/4 turn on way or the other and synchronizer should drop into place when it meshes with oil pump drive shaft, then turn crank back to TDC and recheck syncronizer shaft position, exact is what you want, close is not great, pull it back out and rotate shaft one gear over and try it again.
Pictures here: http://www.therangerstation.com/tech_library/4_0-camshaft_synchronizer.shtml

No white smoke on startup, also the overflow tank is not filling up. There is a small drop in quantity in the overflow tank over time. I don't drive the truck that much due to my work schedule. Could it be just the intake gasket leaking and no need to pull the heads? Or would you go ahead and pull the heads and get them checked? I have not changed the coolant on a regular basis. Yes I plan on all new bolts, $7.78 per bolt from Ford.

Thanks for the heads up on the valve stem seals and the suggestion about the exhaust/muffler bolts, great idea.

Regarding the cam position sensor, I didn't see that in the Ford manual or the Haynes manual, I will look again.

Thanks,

Jeff

Found the cam position sensor in the manual. I can see the general area on the truck, it's buried in the back. Seems like a "fun" job to do that part.

Just reads like a coolant leak, not a head issue, so no I wouldn't pull the heads just because.

I would get some Ultraviolet dye(UV Dye) and add some to the coolant, then drive it for a few days.
Then take a look for the source of the leak(s), dye will trace it back to where it is coming from not just where it is dripping from.

You can get UV Dye kits that come with dye and a small UV flash light, any auto parts store will have them.
The reason for the UV dye is so it doesn't leave visible stains on driveway or engine

So be absolutely sure where the leak is before digging in.

I pulled 1/2 an engine apart trying to find a leak once........................
Turned out is was a small pin hole leak in a HOSE!!!!
It was spraying out onto another part of the engine, the part I disassembled, didn't find it until I had put it all back together and STILL HAD THE LEAK, lol.

They say you learn more from your mistakes than from your successes..................
I felt like a friggin' genius that day

Thanks, that's great info. I would rather not dig into the heads if I don't have to. Read about the cam position sensor, sounds like a pain to mess with.

I will get the dye kit. I have to work for a few days but will get it on Saturday.

Will report back.

Thanks again,

Jeff