Ford Spark Plug Blow Out Problems How to Repair

Summary: Ford spark plug blowout repair is covered in this article primarily for the Triton 4.6, 5.4 & 6.8 liter SOHC (Single Over Head) engines. If you have a different application, no problem, for a wider coverage of spark plug thread repairs see our Time-Sert thread repair kit section. Don't have time to read to figure out which kit is best for your application? We can help. Please let us know what you're working on using our contact us form or give us a call at 800-524-9783 x251, we'll be glad to make a recommendation when ordering from us. We also specialize in larger thread repairs needed to fix threads when a parts store type thread repair was used previously and failed making the hole bigger. 

There are many different brand spark plug thread repair kits available for the common Ford spark plug blowout problem, however they are not all as effective and long lasting as the solutions we recommend. Many Ford dealers and other repair shops quote thousands of dollars to replace the cylinder heads. One mobile repair service charges $800 plus expenses to fly to you and fix your spark plug threads. We have a better idea, fix it yourself and use the difference for your own vacation! 

Our spark plug thread repair kits are used by DIYers and professional auto repair shops, saving our customers a lot down time and expense. Our spark plug thread repairs kits, fix parts store brand failures and can be done in the vehicle, over the fender for a fraction of the cost of replacing the cylinder head or paying for someone's vacation. The Calvan 38900 and the Time Sert kits like 5553 and the 5600 are the best repair systems on the market today using steel alloy inserts that share similar properties with aluminum, but are much stronger! 
The Time-Sert 5600 has the largest outside diameter insert available which can be used when previous repairs have made the hole so large that the Calvan 38900 cannot work. The Time Sert 5600 spark plug thread repair kit also works for more applications than the Calvan 38900 does. We have the "How to" video (below) that demonstrates how to use the largest kit available (Time Sert 5600) to finally fix the dreaded "repeat" blown out spark plug problem that has left the hole too big to fix for regular kits.

We've sold many of these spark plug thread repair kits, saving Ford owners a lot of time - and money in the process. In the following article we'll explain why this should be the next and last "over the fender" repair (even in vans) purchased for this particular application. Again we can assist with choosing the correct kit, but below is a basic guideline for Ford 4.6, 5.4 & 6.8 engines that use M14x1.25 spark plugs.

Time Sert 5553 - Repairs spark plug holes smaller than .663" (16.8mm). The outside diameter of the insert is .69"- it's Double Over-sized, used on many applications and has a Triton counter-bore needed for some 2001 and up. *Note Add-On Kit 5588 for repairing holes larger than .663" (16.8mm) repairing holes up to .73". Works for SOHC and DOHC engines. This kit is Made in the USA. 

Time Sert 5600 - Stand Alone Kit that repairs spark plug holes larger than .663" (16.8mm). The outside diameter of the largest insert is .77" - it's Triple Oversized. Used on many applications and has a Triton counter-bore needed for some 2001 and up.*Note Add-On Kit for installing the Double Over-sized inserts for holes smaller than .663" (16.8mm) is kit number - 5588. Works for SOHC and DOHC engines. This kit is Made in the USA.  

Calvan 38900- Over sized kit that repairs spark plug holes up to approximately .678" (17.24mm) which is the reamer O.D. The outside diameter of the insert is .73". Due to the guide being required this kit has a limited application (compared to Time Sert ). Fits only Ford SOHC 4.6, 5.4 and 6.8 engines from around 1996 to 2003 (some models up to 2016). See our Calvan 38900 listing for more application details. Since there's no counter-bore for certain engines from 2001 and up for this brand, Time Sert recommends their kits, although we have not heard of any issues when using the 38900 kit. The 38900 works for only certain SOHC engines. This kit is made with some USA parts & Globally sourced components.

Ford 3V Engines
Note that some 2004-08 3V engines use a different kit for M16x1.25 - Calvan 39300 or Time-Sert 3221 DLT. The Calvan 38900 DLT is for Triton engines from 1998-2003 (some models up to 2016), if working on a DOHC InTech engine, use Time-Sert 5553 or 5600. If working on a 2004-08 3V engine with M16x1.5 spark plugs use the Calvan 39300 or the TIME-SERT 3221. Some 2008's and newer use 4212H for M12x1.25 Spark Plugs. The 4212H also works on newer Ford's that use the M12x1.25 spark plugs including some Ford Escape and Ford Fusion with 1.5 Liter engines. Make sure M12x1.25 is the plug size. If it's a a 1.6 it will be different.
Ford Spark Plug Blow Out Repair Kit Info
Ford blown out spark plugs is a common problem with engines in Ford F150 pick up trucks, Mustangs, Crown Victoria's, Vans, Expeditions and motor homes. A video showing spark plug thread repair using Calvan spark plug inserts being installed can be viewed on the Calvan 38900 description page. Read on for more information.

Ford 4.6, 5.4 and 6.8 modular engines are prone to spark plugs being blown out of the cylinders due to the aluminum threads failing. When the threads are about to come loose there is often a slight ticking sound/noise, like a small "exhaust manifold leak" would sound.

When the spark plug threads fail, it can eject the spark plug and break the ignition coil on the "coil over spark plug" design. Although rare, it is possible an engine compartment fire can erupt due to the raw fuel escaping the engine cylinder and the broken coil dangling, providing the spark. The cause of failure of the spark plug threads can be debated; poor design, over-torqueing, under-tightening can allow the spark plug to vibrate and wear threads while held in by the coil, until the threads deteriorate and eventually fail. We have many Ford dealers that use Time Sert and Calvan, however there are some Ford dealers that will not recommend repairing the threads. Many only recommend replacing the cylinder head. Because of the expense of labor and parts involved in replacing the heads we recommend using the appropriate thread repair kit made by Time Sert or Calvan. After this repair the threads will be stronger than original.

Below is another reason we recommend using the over the fender repair as opposed to removing the heads.
Gaining access to the cylinder head bolts and removing the heads is difficult on trucks and SUV's. To remove and re-torque the heads, most Ford technicians do a "cab off" or "body off" operation. On trucks the cab is unbolted from the frame; on SUV's and vans the entire body is unbolted from the frame, the electrical wiring, AC lines, radiator hoses, heater hoses, master cylinder, etc. are disconnected. This allows the tech to use the car lift to raise the cab or body off of the frame. Once this is done the engine can be serviced much easier. This process takes less time than you might expect after the tech has done a few of these and knows exactly what needs to be done. However, using one of our kits and eliminating the need to do all that extra work is obviously the most cost effective method.
Below explains the difference between HeliCoil and the Time Sert and Calvan type insert

Many techs at car repair shops will use a Heli-coil repair kit to install a new Heli-coil insert. Techs are familiar with HeliCoils that are good for many applications. The name HeliCoil is used as a generic name for a thread insert. This is similar to how some people say "Kleenex" but they are really using the term as a generic term for facial tissue. Just to clarify though; The Time Sert and Calvan type inserts are NOT the same as the Heli Coil. The Time Sert and the Calvan inserts are much thicker and much stronger and will not leak compression. They also last the life of the vehicle. That being said, I actually have used the Heli-coil (wire coil) repair kit on two different occasions (years before I started selling tools) and neither of them failed that I am aware of. Sometimes they fail when the spark plug is removed on the next plug change. One concern of using the Heli-coil is that combustion pressure may escape the cylinder since the spark plug may not seat perfectly. I am also aware of a very experienced tech (also an ASE Master Tech) I used to work with, that installed a Heli-coil. However it did fail within a week after it's installation. The cylinder head was removed and sent to the machine shop, subsequently it was deemed as "not repairable" by the machine shop. If we would have only known about the Time Sert and Calvan repair kits back then, the cylinder could have been saved. This is because the Time Sert and Calvan inserts are much thicker and are large enough to repair a spark plug hole that has had a Helicoil fail previously. In fact, we commonly sell to customers that have had a Heli-Coil repair fail and blow back out. We also have had many customers that have tried cheap parts store kits that only bought them a little time, before they were back in the same situation, with a Blown spark plug.
Dorman 42025 HELP
The Dorman China (and Mexico more recently) made DIY kit that parts stores have been selling a lot. They have been keeping us VERY busy. It's what we consider a temporary repair because it relies on a self tapping adapter and uses a Ford 3V spark plug! Sometimes they last a little while, sometimes they leak compression and sometimes won't even thread in at all. We sell the Time Sert 5600 and Calvan 38900 Combo Kit when the Dorman fails. If compression leaks outside of the exterior threads on the Dorman insert/adapter, the hole in the head can become oblong. So it's best NOT to drive a vehicle that's losing compression. One recent customer used the Heli Coil Save-A-Thread kit and it lasted 3 months. He then used a Dorman HELP kit and it lasted a week. In this case it didn't blowout. The heat that resulted from escaping compression melted down the spark plug boot and some hoses. What a disaster! The Dorman self threading sert originally was made in China and most commonly would blow out after awhile making the hole bigger. Dorman changed their manufacturing location to Mexico most recently and now the problem is they break in HALF. This is a new problem. Our kits are designed to drill out aluminum; NOT hardened steel. Therefore the broken piece has to be removed before using one of our kits. Some customers have been able to use the German made Double Edge Extractor kit to remove the broken Dorman piece before repair the threads with one of our kits.
More on repairing damage from the Dorman... Time Sert kits are designed to drill out the bad material and to tap threads into the hole, to accept the new solid insert. The Time Sert installation driver, finishes the threads and expands the bottom of the insert locking it into position. So if you need help after using the Dorman HELP kit, we got you covered! See our second website for more info on the China made Dorman Cylinder Head Repair. Or give us a call at 800-524-9783.

DenLors Tools and sister site has sold thousands of dollars worth of Time Sert and Calvan kits since 2005. The kit numbers listed on this page are continually our best sellers and we've had no reported failures! One of the best features is that the spark plug thread repair inserts can be installed over the fender without the need to remove the cylinder head.

Using the Time Sert or the Calvan Kits
It's worth saying again "these kits have much thicker inserts that can be used when other thinner repairs like the Heli-coil or Sav-A-Thread have failed to hold". Using these kits require about the same access as if you were changing the spark plugs. Just a few steps more. The instruction videos that we provide, layout details on using the kits. Upon request when purchasing from us, we provide a compilation of the tips we think are important when using these kits. These tips are emailed to our customers upon purchase. We will also personally answer questions if needed, but we've found the tips clarify the job.

At checkout just write "Tips" in the Comments field and we will email the tips when processing the order.

Additional Tips

Emailed free after purchase. Just write "Tips" in the comments during checkout.

Time Sert products are proudly made in the USA - Reno Nevada. Horizon Tools (North Carolina) provides us with the Calvan Kit, also sold as Mount9200 and other labels including Blue Point (sold by Snappy for about twice the price). Many of our customers with 4.6 or 5.4 or 6.8 engines, decide to put inserts in all cylinders. Some only fix the failed ones and check the tightness on the others. Either way, this helps prevent the possibility of any future spark plug blow-outs.

Basic Tool List

1. Standard Pliers (not included) 5/8" Spark Plug Socket (not included)
2. 3/8" Drive Extensions (not included)
3. Inspection Scope/Camera (not included) - Use to check for metal in cylinder.
4. Air Ratchet (not included) If a good quality air ratchet is not on hand we can ship one at the same time.
5. Starter Button-optional (not included) Manually turning the engine with a socket and ratchet on the crank bolt eliminates the need for a starter button. 
6. Cylinder Leak Detector (included in 38900 kit) Available separately.
7. Air Blow Gun with 8-12" of Small Tubing (not included)
8. Safety Glasses (not included)
Lubrication like PB Blaster or WD40 (not included)
9. JB Weld (not included) Loctite is included in the Time Sert kits
10. 3/8" Ratchet (not included)
11. Shop Towels (not included)
12. Air Compressor (not included)
13. Brake Cleaner, to help clean out the cylinders and provide clean threads for loctite or JB Weld to adhere to.

Below are a few of the questions we have answered related to spark plug blow outs in Ford and Lincoln vehicles. See our mechanics FAQ tool blog for even more questions answered on this topic.

Question: I have a 1999 Ford F150 with a 4.6 liter Triton engine with 126,000 miles on it. The number 3 spark plug blew out of the cylinder head. I called my local repair shop and was told that this was a common problem with this design engine because of the extremely thin (aluminum) casting in the spark plug area of the engine head, there is only about five threads for a spark plug. How are your inserts better?

Answer: While it is true there are only five threads for the spark plug in this design engine for the spark plug and the Calvan insert has five spark plug threads as well, the Calvan spark plug insert is steel not aluminum and the insert itself is held in place with ten external threads. The Calvan spark plug insert improves the design and durability at fraction of the cost of replacing the cylinder heads with the same design weakness. Time Sert offers fully threaded inserts PN 51457.

Question: I am selling my truck as fast as I can get a spark plug to stay in long enough to get rid of it. I wanted to use a Heli-coil because I won't have to drill, but the thread tool isn't long enough to reach in the spark plug recess, any suggestions?

Answer: I personally recommend the Time Sert or the Calvan tools because they are a better repair, but if you would rather use the thinner Heli-coil insert, the HEL5396-14 has the longer thread tool than the standard Heli-coil kit.

Question: I have Ford van that has had a Sav-A-Thread installed previously, it has blown out and I want to know if the Calvan insert will work since the Sav-A-Thread has left a bigger hole now?

Answer: Yes, the Calvan spark plug repair insert is a larger insert and has worked well for our customers before, saving the expense of replacing the heads. The Time Sert 5600 has the largest outside diameter and therefore can save heads that have pretty large holes. In fact up to .73".
Question: I used a Dorman 42025 cylinder head repair kit on my 2001 Ford F250. I hear compression leaking though. Do you have a thread repair kit that can fix an egg shaped hole?
Answer: Yes. The compression is most likely leaking from around the outside of the Dorman spark plug adapter (insert). The Time Sert 5600 kit (Designed and manufactured in the USA) fixes holes up to almost 3/4" wide. The reamer removes the bad material, leaving nice round hole to work on. Then a thread tap threads the hole to accept a triple oversize insert. It's installed with an installation driver which finishes the bottom threads and expands the bottom, locking it into place. Then a smaller insert goes into that so the original size M14x1.25 spark plug can be used. This is what we call a permanent repair as opposed to the Dorman HELP kit, which we consider temporary based upon the reports we get from our customers.

Question: I bought a rebuilt head and come to find out one spark plug holes had a repair insert, it blew out last week. The cylinder head has a warranty, but I cannot afford the down time all over again. Will the Time Sert or Calvan insert repair this hole?

Answer: Yes, the Time Sert or the Calvan inserts, both have thicker beefier repair inserts that you don't have to worry about. And I always tell our customers that when purchasing a rebuilt head of this type to be aware of the possibility that inferior repair inserts may already be in the head. Buying a brand new head would insure that there are no cheap inserts, but you would be stuck with the original weak design. Either the Time Sert or the Calvan thread inserts will save down time, money and are stronger due to the material being steel alloy instead of aluminum like the original threads.

Related Repair Articles and Specialty Tools

TIME-SERT 5553 - Ford Spark Plug Repair Kit - PN 5553 for DOHC InTech engines and many other Ford applications when used with the proper insert.

Time Sert 5600 - The Largest - Stand Alone Triple Oversized Thread Repair 

Calvan 38900 Ford Spark Plug Insert Kit - for Triton SOHC 1998-2016 with M14x1.25 Taper Seat Plugs. Replacement insert number is 389-100.

Blowout FAQ's Recommended Reading for Using CAL38900 - Your question may be answered in this blog. We've compiled a ton of questions we've had on this job since 2005.

Expedition Cylinder Head Removal Body Off - *Removing the body is NOT required for use of the Time Sert or Calvan thread repair kits. Just see what you're missing!

Video Inspection Cameras - Not all techs use them, but to help verify metal shavings are removed after drilling tapping etc.

Air Ratchets - A good quality air ratchet is recommended by Calvan for drilling, using the bit in the 38900 kit.

TIME-SERT 3221 - for most 2004-2008 3 Valve engines with 16x1.5mm threads.

Calvan 39300 - also for most 2004-2008 3 Valve engines with 16x1.5mm threads.

Below Covers 04 & up Different Ford Spark Plug Problems - 3V Broken Spark Plugs & Porcelain Staying In

Question: I have an 05 Ford F150 with a 5.4 liter engine that has a spark plug broken and I can't remove the broken piece because the part that the spark plug socket goes on came out. I know this is a completely different problem than threads missing, but do you know how I can remove the broken spark plug without removing the head?

Answer: You are right this is a totally different issue, but you're not alone. What we used to sell for this problem was a spark plug remover, a specialty tool made by Rotunda, the number is 303-1203. We use to sell a lot of the 303-1203 special service kits, but now the LIS 65600 is what we sell the most of for removing Ford broken spark plugs. See the LIS 65600 DLT in use tool blog for more information.

Question: I'm looking for Ford Rotunda OTC tool number 303-1398 for removing the ceramic or porcelain part of the spark plug. Thanks, David

Answer: The Rotunda 303-1398 and 303-1203 are pictured above, they are expensive Rotunda specialty tools. Calvan has low cost alternatives and the tool number are CAL39100 & CAL39200. The porcelain extractor tool kit has pins that are loc-tited into the center of the broken porcelain and only can be used once. The the electrode remover can be used.

There is another method though, instead of gluing "one use" pins, a tool manufacturer has a different solution, The LIS65600 DLT broken spark plug remover mentioned before can be used as an alternative option to the 303-1398 & the 303-1203. The Lisle 65600 Ford spark plug remover, is designed to push the ceramic part of the plug further down, but not into the cylinder. Then, the same tool kit removes the electrode shield. This automotive specialty tool kit is used in place of the two Rotunda tools (303-1203 and the 303-1398) at only a fraction of the cost. A special thanks to Bill at ProCare Automotive for being the first to try this tool out and report back to us, since then this is the tool we have passed this information along. He said the LIS 65600 worked perfectly and was happy to know this tool can be used on more than one vehicle, unlike the 303-1398. Since that first sale of the LIS65600, we've sold hundreds with positive feedback! We've also posted a blog that has pictures of the LIS 65600 DLT in use. Be sure to check it out and you'll have a better idea of how this tool works. Click the following to go directly to the Lisle 65600 DLT product listing.