Head gasket removal step by step help.

[Napu(StrongWave)]

I have a 2001 Explorer Sport trac v6 sohc 2wd Gen.1
I need help replacing the head gaskets. Ive already removed the valve covers, fuel rails, vacum lines, removed alternator, thermostat housing, and everything from left front of engine.

 

[Napu(StrongWave)]

Progress

Next took off all the vaccum lines and fuel rails, Main engine wiring, intake upper and lower, exhaust manifolds. Heads are loose, but the only thing keeping it from coming out is the front and rear cassettes.

 

[OffTrac]

I'm not sure if he's covered it but 2000StreetRod has a lot of very useful threads for information like this. I see nobody else is chiming in and it may be because none of the ST board regulars know. I sure don't. I'd check his "List of Useful Threads." If not, you may get more eyeballs on it in the "Under the Hood" subforum. Good luck.

 

[Napu(StrongWave)]

Thanks OffTrac. I have been looking at some threads by 2000StreetRod and it looks like i will have to pull the engine to get to the rear cassette chain. I'm going to attempt to remove the front cassette chain today. Have to pull the power steering pump and a/c compressor to do this.

 

[2000StreetRod]

replacing head gaskets

I normally don't comment on Sport Trac questions because I have no first hand knowledge of them. However, I know that it is not necessary to pull the engine to replace the head gaskets if you have the timing tool kit (OTC-6488). It is necessary to disconnect the camshaft sprocket associated with the head being removed. It is not necessary to remove the cassette. The timing tool kit allows removal of the rear sprocket retaining bolt. I think the sprocket must be separated from the chain, keep the collapsed chain in place with a strong rubber band, have one person hold the chain while the head is lifted by another person.

 

[Napu(StrongWave)]

It looks to me like the rear cassette chain is grinding on a guide bolt. I cannot see inside to evaluate. Im going to try to take a picture of this and post later on.

 

[2000StreetRod]

broken rear guide?

If the rear guide assembly upper positioning bolt looks like mine did as shown below:

then your rear guide assembly probably looks like the photo below.

Remove the positioning bolt and see if you can pull the upper part upward. If it moves straight up its broken. When its not broken it only pivots side to side.

In order to replace the rear guide assembly the engine and transmission must be separated. I prefer pulling the engine instead of pulling the transmission and working under the vehicle in limited space.

 

[Napu(StrongWave)]

Yep! That upper picture of the positioning bolt looks just like mine. The chain was tight up against the positioning bolt before l removed the bolt.. Afterwards I felt the sprocket at the top of rear cassette and it turned itself over once, so just curious I did it again and it turned over once more and stopped. I couldnt tell which way it happened so fast, but now the chain has some slack in it similar to the front cassette.

It looks like the positioning bolt goes through a hole in the rear guide. Beings i only retrived the positioning bolt looks like i will have to replace the rear guides.

Do i have to change the chains also or can i just replace the guides and use the same chains?

 

[2000StreetRod]

upper end missing

If the chain was able to contact the positioning bolt then the upper part of your guide is missing. The danger is that a piece can get wedged between the head and the chain and break the chain resulting in valve/piston collisions. Or, a piece can block an oil passage and starve a bearing surface. I found fragments of my rear guide wedged in the oil pickup screen.

I doubt you can still purchase just a guide assembly. Now you have to purchase the entire cassette (sprockets, chain & guide assembly). Unfortunately, the cassette does not include the upper positioning bolt. See this thread for Ford part numbers: SOHC V6 Timing Chain Related PNs . I try to keep it current. If it's not please let me know. If you order something related not posted please give me the name and part number.

The chains and sprockets last a long time so it is not necessary to replace them when replacing the guide. However, since the engine has to be separated from the transmission, and the camshaft sprocket must be removed to replace the guide assembly, I suggest replacing the entire cassette. Also, I don't know if there is enough clearance in the head to get the guide past the chain. I replaced my cassette as an assembly. You'll need the non-reusable torque-to-yield jackshaft rear sprocket retaining bolt and the cover. The chains and sprockets develop wear patterns so it is suggested to replace the sprockets when the chains are replaced and vice-versa.

 

[Napu(StrongWave)]

I disconnected everything from the engine and unbolted the tranny too today. I pulled a piece of the rear chain guide out of the head today so i know that this will have to be replaced. Ready or not the engine comes out tomorrow.

 

[Napu(StrongWave)]

Engine is out and on stand now. Looking at this engine all week while waiting for cam tool to arrive. I'm going to replace the upper oil pan gasket too. Now i'm just wondering should i change the oil pump too. It has never given me any problems.

 

[Napu(StrongWave)]

Otc-6488

Works great and you can remove the rear cassette bolt from cam using this tool. The rest of the bolts and jack shaft cover are going to give you hell though. If you're doing a head job this is a great tool.

 

[Napu(StrongWave)]

Cylinder heads

With the cams unbolted from timing chain, tensioner removed and timing guides removed.

Now you're ready to unbolt the heads.There are 10 torque to yield bolts for each head. Use a breaker bar or rachet and cheater pipe to remove bolts. (It's a star or torx bit)

It may be hard to see in the oil but around the timing chain and sprocket inside the head there are the 2 smaller bolts. Careful now the head may want to move.

Remove sprocket from chain carefully. The heads are ready to be removed and inspected for cracks and warpage.

Remove head gaskets.

 

[Napu(StrongWave)]

Bad luck

I took my heads off to find both heads are cracked in between the valves.:roll:

 

[Napu(StrongWave)]

Decissions

Now this has me to think if it's better to install a rebuilt or reman. engine?? :scratch:

 

[2000StreetRod]

how long to keep

How long do you plan to keep the vehicle? Remanufactured/rebuilt SOHC V6s are expensive. Some members have purchased low mileage Mustang engine from a salvage yard as a less expensive alternative. One with 50K miles should last at least another 100K miles.

 

[Napu(StrongWave)]

I just installed a re-manufactured 4.0L V6 SOHC from Marshall $2200.
I just fired it up and it sounded great..when it reached temp. it started to make a wierd noise coming from the driver valve area,like a ticking,tapping/clicking noise.
Manufacture directions read, to adjust the valves after the engine reaches temp. and re-torque heads.

Are the valves adjustable on this engine?
Maybe tensioner is the problem?

 

[2000StreetRod]

valves not adjustable

I just installed a re-manufactured 4.0L V6 SOHC from Marshall $2200.
I just fired it up and it sounded great..when it reached temp. it started to make a wierd noise coming from the driver valve area,like a ticking,tapping/clicking noise.
Manufacture directions read, to adjust the valves after the engine reaches temp. and re-torque heads.

Are the valves adjustable on this engine?
Maybe tensioner is the problem?

The valves are not adjustable. The valve clearance is controlled by the hydraulic lash adjusters. There may be air in the adjusters. Haynes suggests: "After the engine is warmed-up, raise the speed from idle to 3,000 rpm for one minute. Stop the engine and let it cool down. All of the noise should be gone when it is restarted."

I had a similar symptom after replacing my timing components which took several weeks. I did a short WOT run in first gear and the noise went away for good.