cross threaded spark plug
#1
cross threaded spark plug
I was replacing my plugs in my 89 2wd pu with 22r motor (carb) when # 4 plug wouldnt thread straight. I kept trying to restart jt about 20 times but she wouldnt go. Finally I had to stuff it in in order to drive to work. Seems to run ok but can't keep it like that.
What can I do to fix this? How difficult is this to do? I took it to the local shop and they quoted me $180 to repair. Ive heard of heli coil but never done one.
Anyone have any other ideas? Thanks.
What can I do to fix this? How difficult is this to do? I took it to the local shop and they quoted me $180 to repair. Ive heard of heli coil but never done one.
Anyone have any other ideas? Thanks.
#4
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I did that same thing. Just jam the plug in and leave it alone! Some time later when you can risk removing the head; you can try to use a thread chaser on it but its not pleasant. I never fixed it, I sold it and 3 weeks later it was totaled.
The real issue is you have no room to work back there with all the hoses, so it turns into a day long project with the worst that can happen is you have to pull the head for replacement or repair.
The real issue is you have no room to work back there with all the hoses, so it turns into a day long project with the worst that can happen is you have to pull the head for replacement or repair.
#5
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A helicoil is a "permanent" fix, so I wouldn't call it a last resort. But I wouldn't try to put one in unless I had the head off. A spark plug isn't designed to cut threads, but you did, and crooked. A helicoil tap can do much more damage if you don't have it straight.
First thing I would do is check the compression. Maybe stuffing the plug in worked! If your compression is low, you know the most likely culprit, and a helicoil is what you need.
For just $180, I'm guessing the shop thinks they can do the helicoil while the head is still on. If you think they can do it, that sounds like a pretty reasonable price.
First thing I would do is check the compression. Maybe stuffing the plug in worked! If your compression is low, you know the most likely culprit, and a helicoil is what you need.
For just $180, I'm guessing the shop thinks they can do the helicoil while the head is still on. If you think they can do it, that sounds like a pretty reasonable price.
#7
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A heli coil can be done with the cylinder head on. Cylinder head sould only be pulled as a last resort. The best repairs are the ones made by Time-sert. They have a knurled section at the top of a solid insert, and a swagging tool that is used to expand the top half of the insert into the head.
There are many different ways to do this correctly, following the instructions on the Time-sert package and it will go fine. Leaving the plug in cross threaded can lead to the plug being blown out of the hole. Also the surface area of the plug threads dissipate the heat of the plug, you will likely run into the plug going bad quicker. Worst case scenario if the plug begins to loosen up under compression the plug will not seal, the combustion gasses will heat the material around the plug causing erosion and also causing the aluminum to become brittle, then when you try to tap it, the aluminum will just crumble. I have seen this so many times on 22re motors and ford 5.4l engines.
Many OEM's have procedures and kits for spark plug repairs without thread removal.
If you need any info that can help let me know, I have done probably 50-60 repairs with the Time-Sert kits on aluminum head vehicles.
Dave
There are many different ways to do this correctly, following the instructions on the Time-sert package and it will go fine. Leaving the plug in cross threaded can lead to the plug being blown out of the hole. Also the surface area of the plug threads dissipate the heat of the plug, you will likely run into the plug going bad quicker. Worst case scenario if the plug begins to loosen up under compression the plug will not seal, the combustion gasses will heat the material around the plug causing erosion and also causing the aluminum to become brittle, then when you try to tap it, the aluminum will just crumble. I have seen this so many times on 22re motors and ford 5.4l engines.
Many OEM's have procedures and kits for spark plug repairs without thread removal.
If you need any info that can help let me know, I have done probably 50-60 repairs with the Time-Sert kits on aluminum head vehicles.
Dave
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#8
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Oh and a tip for you guys when changing plugs. Tear off an old spark plug boot from an old set of plug wires, or use some fuel hose. Put it over the porcelain end of the plug and use that to thread the plug in, it will keep it from cross threading of marring the threads.
After 3-4 full turns you can pop off your new "Tool" and used the spark plug socket and ratchet to tighten the plug down. I also highly recommend using a torque wrench to tighten the plugs to specs, it will keep the threads happy for a very long time.
Dave
After 3-4 full turns you can pop off your new "Tool" and used the spark plug socket and ratchet to tighten the plug down. I also highly recommend using a torque wrench to tighten the plugs to specs, it will keep the threads happy for a very long time.
Dave
#9
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I'd recommend against doing any thread casing or other tapping while it was mounted, you really don't want to be having to repair the block too.
Drop some oil into the plug area, run the engine and look for bubbles no bubbles means your ok till it's time for the next tune up and you have time to set aside money for a new gasket and any tools you might need.
And of course it's obviously best repaired correctly and sooner rather than later.
The hose is a great trick, if you don't have a sparkplug socket with the rubber stuff in the top. I'll pass on another you've likely heard already, when starting a thread start turning it counter clockwise first and you'll feel it drop into the thread grooves and you can spin it in without cross threading.
Drop some oil into the plug area, run the engine and look for bubbles no bubbles means your ok till it's time for the next tune up and you have time to set aside money for a new gasket and any tools you might need.
And of course it's obviously best repaired correctly and sooner rather than later.
The hose is a great trick, if you don't have a sparkplug socket with the rubber stuff in the top. I'll pass on another you've likely heard already, when starting a thread start turning it counter clockwise first and you'll feel it drop into the thread grooves and you can spin it in without cross threading.
#11
Thanks for all the tips. I'm gonna try one more time with a better socket and see if I can get it in straight. If not I'll take it in an find someone to fix it. I don't have a garage and my apartments don't allow you to work on cars.
Otherwise its been a great truck. I bought it from a bud whose wife had a baby an needed more room. He put in a crate motor in 04. Got it for $500 with a bad clutch cylinder.
Otherwise its been a great truck. I bought it from a bud whose wife had a baby an needed more room. He put in a crate motor in 04. Got it for $500 with a bad clutch cylinder.
#12
Registered User
A heli coil can be done with the cylinder head on. Cylinder head sould only be pulled as a last resort. The best repairs are the ones made by Time-sert. They have a knurled section at the top of a solid insert, and a swagging tool that is used to expand the top half of the insert into the head.
There are many different ways to do this correctly, following the instructions on the Time-sert package and it will go fine. Leaving the plug in cross threaded can lead to the plug being blown out of the hole. Also the surface area of the plug threads dissipate the heat of the plug, you will likely run into the plug going bad quicker. Worst case scenario if the plug begins to loosen up under compression the plug will not seal, the combustion gasses will heat the material around the plug causing erosion and also causing the aluminum to become brittle, then when you try to tap it, the aluminum will just crumble. I have seen this so many times on 22re motors and ford 5.4l engines.
Many OEM's have procedures and kits for spark plug repairs without thread removal.
If you need any info that can help let me know, I have done probably 50-60 repairs with the Time-Sert kits on aluminum head vehicles.
Dave
There are many different ways to do this correctly, following the instructions on the Time-sert package and it will go fine. Leaving the plug in cross threaded can lead to the plug being blown out of the hole. Also the surface area of the plug threads dissipate the heat of the plug, you will likely run into the plug going bad quicker. Worst case scenario if the plug begins to loosen up under compression the plug will not seal, the combustion gasses will heat the material around the plug causing erosion and also causing the aluminum to become brittle, then when you try to tap it, the aluminum will just crumble. I have seen this so many times on 22re motors and ford 5.4l engines.
Many OEM's have procedures and kits for spark plug repairs without thread removal.
If you need any info that can help let me know, I have done probably 50-60 repairs with the Time-Sert kits on aluminum head vehicles.
Dave
#13
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Thanks for all the tips. I'm gonna try one more time with a better socket and see if I can get it in straight. If not I'll take it in an find someone to fix it. I don't have a garage and my apartments don't allow you to work on cars.
Otherwise its been a great truck. I bought it from a bud whose wife had a baby an needed more room. He put in a crate motor in 04. Got it for $500 with a bad clutch cylinder.
Otherwise its been a great truck. I bought it from a bud whose wife had a baby an needed more room. He put in a crate motor in 04. Got it for $500 with a bad clutch cylinder.
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