I have a van with the 5.4 motor that has blown out the same plug twice. The shop that looked at it said I need a new head. I don't have the money for that right now but I need the van in order to work. My idea is this: take the rocker arms off of the bad cylinder. This way the valves stay closed and I am basically running a 7 cylinder. If I could drive like this for a few weeks I could get the money no have the head replaced. Are there any problems with closing off the cylinder ? One thing I am worried about is oil for that piston.

 

there are kits to repair this on the truck. ford won't tell you about them as a rule. they ain't cheap. this is a design flaw in all later mod heads, not enough threads.

 

Tony, I would like to try one of the repair kits, but this cylinder has been repaired twice already. The shop told me there was not enough metal left to fix it.

 

your already looking at a pretty significant amount of labor to pull a rocker right? Also You you'd have to do something about fuel and spark in the 'dead' cylinder. I had mine helicoiled for about $300 something, but never had to go through it more than once

 

If you do remove the rockers you will still have the huffing and chuffing noise because the plug is not there to contain it, don't expect it to be quiet. If you are willing to put up with the noise just unplug the wires from the fuel injector and maybe the coil, leaving the rockers in place. It won't matter if the rockers are there and if you remove them you could cause damage to the engine due to the loss of oil pressure as the rockers depend on the oil pressure to actuate hydraulicaly and without them in place you will be syphoning off oil pressure that is needed elsewhere in the engine.

I feel for you, been there, done that, Life's a bitch and then you die.

 

Mel, I have been driving it with the spark and fuel disconnected to that cylinder. The problem is that with the plug not in there it is like running the motor with a huge vacuum leak. It runs like ****. Has no power (as in can barely get upto 30 mph). And it is only getting 5 mpg. I need the truck to make money and I need to work for a few weeks to get the money for a new head.

 

It is pretty certain that if you go to all the trouble of removing the rocker assemblys you will do much worse damage to your engine by losing oil pressure. That would be a lot of work just to turn the engine into junk.
The only real solution is to park it and borrow or rent a truck until you can fix it.
With the old school engines you could easily remove the rockers for that cylinder but with these Modulars the cams are on top of the roller rockers and there is a large oil jet under the hydraulic tappet, if you remove the rocker the tappet will pop out of its chamber and most or all of your oil pressure will be lost, wasting your engine. In addition to all this good news you must remove the cam to take the rockers out and have the cam timed before trying to remove it.
These are interference engines and if you remove the cam gear without locking the cam in the proper position the valve spring pressure will cause the cam to move which will in turn cause the valves in some cylinders to hit the pistons, bending them. The manual says that damage will occur not that it may occur.
I know you are between a rock and a hard place but there seems to be no alternative to parking it until you do the job correctly or pay someone to do it for you. These are not easy engines to work on, especially for those of us who are used to the OHV engines that we all had until the '90s. Now all the old school guys are pretty much screwed. And that certainly includes me. I'm still pissed off because I had to buy metric tools, Damn Frenchies.

 

One suggestion that might work. It's a long shot but here it is. Check the spark plug thread diameter against that of a pipe plug 1/8" or 1/4" that use an allen head wrench to tighten. These plugs run larger than the size stated so you need to measure. If the plug is slightly larger diameter than the sparkplug hole you may be able to put a pipe thread in the sparkplug hole. Even if you have to drill or ream the hole a little to get to the right size it won't make a difference as the head is junk anyway. Make it fit and either vacuum or blow the aluminum chips/shavings out of the cylinder. This is definately a "Double Down and Dirty" method and I would not recommend this to anyone not in a situation like yours. It might work for a while and it would stop the noise and the vacuum leak and might even give a little better gas mileage. I hope so.

 

Mel thanks for the suggestion. I thought about doing something similar, but was afraid that whatever I used to plug up the sparkplug hole would go to far into the combustion chamber and hit the piston or valves.

I decided to park the van until I can afford a new head. I was able to get the old head off FINALLY. Now I think I might as well replace both heads with ones that have steel thread inserts for the sparkplugs so that I NEVER have to deal with this problem again.

Do I need to put on a new timing chain set if I replace both heads ?

 

It would be a good idea to pull the other head and install Heli-Coils in every plug hole. You already have at least 2/3 of the labor done and it would be a shame to have the same thing happen on the other head.

A new chain would be a good idea as well as carefully inspecting the chain guides. At this point if the guides are iffy, change them and get it done right the first time. The guides get brittle with the constant heat cycles so be very carefull.
Good luck with it and let us know how it comes out.

 

Not Heli-coils. Timeserts

 

That is what I meant by "steel inserts". I am taking it that that is what a timesert is ?

 

It won't lose oil pressure by removing the cam followers. It's not like a pushrod engine. They run all of the time when the followers fall off.
It will still be a pig only running on 7 cylinders.

 

Yup!

 

I have a lot of experience using Heli-Coils on motorcycles and none with Time Serts, I'll give them a try when and if I need them. Hopefully never for spark plug holes.