Stripped spark plug hole

[iTurbo]

So I decided to change the spark plugs on the 2003 FX4 Level II I had just bought for my Dad. The truck had a random misfire and I figured the plugs would be a good start. I had replaced most of the old plugs, which were Autolite platinums that were very worn out. Then I get to the middle spark plug on the driver side and it just feels wierd while I'm unscrewing it. Turns out that the threads were stripped and whoever replaced them before jammed it in there and it was only threaded half way into the head, which likely explains the misfire it was having. After I got it out, sure enough the threads on the spark plug are boogered. Great.

Now I can't even get a new plug in. It starts out OK but after about 1 turn it jams on the boogered threads. I don't want to force it either. I *always* thread spark plugs in by hand with a very small amount of anti sieze on the threads to prevent this, but it looks like it's too late for that.

I have in the past successfully used a threaded insert to fix stripped spark plug threads. However, it doesn't look like I'll have enough room to get a drill in there to drill out the old threads. Am I going to have to remove the cylinder head at this point? Help!

 

[kimcrwbr1]

You can try chasing the threads with a tap first get a can of axle grease and dunk the tap in the grease to catch the shavings run it in a turn or two and back out clean the tap and do it again. Hopefully the spark plug hole will have enough threads so you can get the plug tight. You can do the same thing with a helicoil kit use lots of grease and keep the drill and tap clean and loaded with grease.

 

[adsm08]

Timeserts.

Google it, buy it, use it, be happy.

 

[iTurbo]

Looks like the Time Sert is the way to go, although I'm sure the kit will be expensive (but worth it).

Can anybody tell me if this is the proper kit to use?

P/N 5553
http://www.timesert.com/html/triton_repair.html

I found that the 4.0L SOHC engine uses 14mm x 1.25 spark plug threads, but the application does not specifically list the 4.0L.

 

[veefer800canuck]

If there is no room to drill it in situ, you might have to remove the head and fix it on the workbench.

Helicoil or TimeSert will do. OR, you could replace the head if you are really anal.

I did the threaded insert method on my father-in-law's Toyota, but it was a 4 cylinder, so easy to reach. I did it right on the truck, with the piston at BDC, greased the hell out of the drill bit, greased the hell out of the tap, and cranked the engine over quite a bit before putting the sparkplug back in, to hopefully purge any chips out of the cylinder.

Blowing it out with compressed air using a long piece of tubing might help too.

That Toyota ran for years and years afterwards just fine.

 

[iTurbo]

Yup I've used the NAPA brand inserts before on my old turbo Mopars and they've never failed. Those were SOHC four cylinders so access was easy on those... they were formed inserts, not the wire type heli-coil and had to be drilled, tapped, then staked in place..

Nice thing about the time serts is that it uses hand tools for counterboring, reaming, tapping....no need to drill which is nice because there isn't room to get a drill in there with the head installed.

Hoping like hell I can fix this without removing the cylinder head. I'll report back whatever happens.

 

[aspevacek]

http://www.amazon.com/KD-Tools-Internal-Thread-Rethread/dp/B000J4K01G?tag=959media-20

is a better choice then drillin git out and cutting threads to put a time sert in there. Yes they will fix it but I think the above tool is a much better choice.

 

[doorgunner]

Been there.......saying a prayer for you & the threads......

 

[adsm08]

The one you linked to is for the 4.6 & 5.4 L engines. They did make one for the 4.0.

Postin' from teh Galaxy

 

[iTurbo]

Thanks, I did send them an inquiry via their web site so hopefully I will know exactly what part # to get soon.

 

[aspevacek]

I just grabbed one at random. I know they make them in all plug sizes and would be alot easier.

 

[iTurbo]

I got an email from Time Fastener Company, the makers of Time Sert. They say the proper kit to use with the Ford 4.0L SOHC is the '5141E' kit. It goes for $316.44 and inserts are sold separately. The insert is '51457' and they are $10.04 each.

Gonna have to wait for payday to get this

 

[iTurbo]

I got an email from Time Fastener Company, the makers of Time Sert. They say the proper kit to use with the Ford 4.0L SOHC is the '5141E' kit. It goes for $316.44 and inserts are sold separately. The insert is '51457' and they are $10.04 each.

Gonna have to wait for payday to get this

 

[RonD]

From your description it sounds like the hole is cross-threaded at the top.
Spark plug threads are softer metal than the head threads, so head threads should be recoverable.

I would do what kimcrwbr1 suggested and just try the correct tap to get down to the good threads.

JEGS has an interesting approach, never used it but it is interesting
JEGS Performance Products#555-80595

The tap is on a mandrel so the tap expands to correct size after you insert it into the spark plug hole, so you are tapping the hole from the bottom up, assuming good threads at the bottom of the hole it would un-cross-thread the upper part of the hole.
Even if upper threads came off completely you would be no worse off and may have enough threads at the bottom for good tightening.
Interesting.
Can't find any reviews of it so probably doesn't work, lol.

 

[veefer800canuck]

I got an email from Time Fastener Company, the makers of Time Sert. They say the proper kit to use with the Ford 4.0L SOHC is the '5141E' kit. It goes for $316.44 and inserts are sold separately. The insert is '51457' and they are $10.04 each.

Gonna have to wait for payday to get this

For that much money, you could buy an entire rebuilt cylinder head with valves and springs already installed, and swap the head yourself.