Spark Plug issue

Knightspirit

Well-known member
Sep 22, 2019
251
84
Mount Shasta, CA
As I was driving home the other day - my truck started slowing down and hesitating like it was going to die. It kept going, but at about 45 mph and I stuttered home on the side of the freeway. As I got to my exit, it suddenly came back to life and ran normally the rest of the way home. So I am thinking the usual things:
- Fuel filter
- plugs
- wires

None of which I have even looked at since I bought the thing. So I pulled the first plug (#1) which looked great, cleaned it a bit and went to put it back in, and I could not for the life of me get it to go back in - it keeps jamming up. I didn't force it obviously. So I took out the next one (#3) and it looked great - cleaned it up, and tried to put it into the #1 slot just to see if it was the plug - but same thing. Then I went to put it back in into #3 and it too jammed up.

What am I missing here? Is there something I need to be doing to get these threaded back in properly?

I was going to just buy new ones, but it looks like these were all replaced just before they sold the car. Now I'm afraid to pull any more out.
 

Tugela

Well-known member
May 21, 2007
4,754
562
Seattle
What tools and materials are you using? I have a spark plug socket that I attach to my ratchet via an extension and U-joint. I put a small dab of copper anti-seize on the threads of the spark plug before inserting, which makes it go a little easier. Maybe also clean the threads out in the block. The angles at which the spark plugs go in vary across cylinders, so I'd continue fiddling gently until you get the threads to seat properly. Check the corresponding plug on the opposite side of the engine for reference on position.

While you have your plugs out, you might as well check the gap on them. If you don't know the history of the truck, you might as well just replace all the plugs (arguably the wires, too). It's a small investment.
 
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JUKE179r

Well-known member
Sep 14, 2016
761
95
Suffolkshire, UK
Definitely recheck the gaps.
Take a fuel line, insert the spark plug in it and use the fuel line to screw in the spark plug. Keeps it from cross threading.
80-c315dd0a_b535_47c1_9254_b091c1cfb25e_c693df1999264b94e6a4ebf6035f32dab854c73e.jpeg
 

Flyfish

Well-known member
Oct 29, 2004
1,402
212
52
St. Louis
You’re just not lining them up properly. All of the plugs sit at an angle. Just look at the face angle of the hole and it will easily go in by hand.
 
Last edited:

Knightspirit

Well-known member
Sep 22, 2019
251
84
Mount Shasta, CA
You would think this would be easy! I still am not able to get either of the two plugs that I removed replaced. Even with new plugs, anti seize and wD40. I can get a few turns in and then it stops. I wonder if these threads were goobered? Really hard to see - but I was able to get a phone pic. Should I just get a tap and put that in a few turns? I can see the correct angle and feel it when turning by hand. Might try the fuel line trick...

IMG_5950.JPG

IMG_5949.JPG
 

Flyfish

Well-known member
Oct 29, 2004
1,402
212
52
St. Louis
The problem is the threads, not you. I would definitely get a spark plug tap and be careful to get the proper alignment! Try turning by hand, otherwise go slowly with a socket wrench. Maybe put bearing grease on the tap to capture any metal pieces.
 

Knightspirit

Well-known member
Sep 22, 2019
251
84
Mount Shasta, CA
The problem is the threads, not you. I would definitely get a spark plug tap and be careful to get the proper alignment! Try turning by hand, otherwise go slowly with a socket wrench. Maybe put bearing grease on the tap to capture any metal pieces.
That was my thought - thanks for confirming!
 

Jimmy

Well-known member
Apr 10, 2006
740
64
Aurora, CO
Thread chasers are preferred over taps to clean threads. As mentioned, grease in the flutes/grooves will hold onto most of the debris.
 

Flyfish

Well-known member
Oct 29, 2004
1,402
212
52
St. Louis
Thread chasers are preferred over taps to clean threads. As mentioned, grease in the flutes/grooves will hold onto most of the debris.
This is what I meant when I said spark plug tap.... it’s what I use. Just the wrong lingo.

FB63AAF8-569C-4581-AF38-62700D38E333.jpeg
 

Knightspirit

Well-known member
Sep 22, 2019
251
84
Mount Shasta, CA
Just to follow up - I ended up using a helicoil. Bought the kit from Stanley and it worked great. Used grease to catch the filings and then blew out the cylinder with air - then cleaned the threads with brake cleaner. Used the red lock tight on the helicoil insert and copper ant-seize on the plug. Voila!
 

Jimmy

Well-known member
Apr 10, 2006
740
64
Aurora, CO
New wire set is the best answer. In a pinch, you can get by with slathering the boot and tower with dielectric grease to stop the arcing.