Ford Spark Plug Blow Out Problems How to Repair
![]() By Dennis Bandy
© DenLorsTools.com Summary: Ford spark plug blowout repair is covered in this article for the Triton 4.6, 5.4 & 6.8 liter SOHC (Single Over Head) engines. Don't have a Ford? No problem, for a wider coverage of spark plug thread repairs see our Time-Sert Kits. There are different brand insert repairs available for this Ford spark plug problem, however they are not all as effective and long lasting as the solution we recommend. Many Ford dealers want to charge thousands to replace the cylinder heads, when our repair can be done in the vehicle for a fraction of the cost. We sell some competitive brands like Lisle and Helicoil, however the Horizon made Calvan 38900 (Mount.9200 same w/different labeling) is the best repair system on the market today using a steel alloy insert that shares similar properties with aluminum, but is much stronger!
We've sold hundreds 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. Be sure to visit the FAQ tool blog which is recommended reading if doing the job for the first time and finally the Calvan 38900 product page when ready to purchase. Note that 2004 and up 3V engines use a different kit - Calvan 39300 or Time-Sert 3221 DLT. The Calvan 38900 DLT is for Triton engines, if working on a DOHC InTech engine, use Time-Sert 5553 DLT.
Ford spark plugs blowing out is a common problem with Triton engines in Ford F150 pick up trucks, Mustangs, Crown Victorias, Vans, Expeditions and motor homes made before 2004. A video showing spark repair inserts being installed can be viewed on the Calvan specialty tool 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 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 start 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 the threads deteriorate and fail. We have some Ford dealers that use our kit, however most Ford dealers will not recommend repairing the threads. They only recommend replacing the cylinder head. The expense involved unless the vehicle is still under an aftermarket warranty can run into the thousands of dollars.
Gaining access to the cylinder head bolts 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 allowing 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.
Many techs at car repair shops will use a Heli-coil repair kit to install a new Heli-coil insert. I myself have used the Heli-coil repair kit on two different occasions and neither of them failed that I am aware of. 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 a master tech) I use to work with that used the 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". If we would have only known about the Calvan 38900 repair kit back then, the cylinder could have been saved. This is because the Calvan insert is large enough to repair a spark plug hole that has had a Helicoil. We commonly sell to customers that have had a Heli-Coil repair fail and blow back out.
Best of all the repair is done over the fender without the need to remove the cylinder head.
Using the Calvan 38900 Specialty Tool Kit
It's worth saying again "the Calvan kit has a much thicker insert that can be used when other thinner repairs like the Heli-coil has failed to hold". Using the kit requires about the same access as if you were changing the spark plugs. Just a few steps more. The instruction video provides details on using the kit, but there are more tips that we have developed over the years that we have been selling this kit. 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.
Tips
1. Emailed free after purchase.
2. Emailed free after purchase.
3. Emailed free after purchase.
4. Emailed free after purchase.
The guys at Horizon Tools have really done their homework. One of our customers has a Ford speed shop and when they are beefing up any 4.6 or 5.4 engine, all eight cylinders gets a new Calvan insert to prevent any spark plug blow-outs.
Tool List
Below are a few of the questions we have answered relate to spark plug blow outs in Ford and Lincoln vehicles. See our mechanics FAQ tool blog for even more questions answered on this topic.
Q: 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 is the Calvan insert better?
A: While it is true there is 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. Q: 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?
A: I personally recommend the Calvan tool because it is 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.
Q: I have Ford van that has had a TimeSert installed previously, it has blown out and I want to know if the Calvan insert will work since the Time Sert has left a bigger hole now?
A: 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. See our auto repair/tool blog for more information.
Q: 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 Calvan insert repair this hole?
A: Yes, the Calvan insert is a thicker beefier repair 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 possibilty that inferior repair inserts may 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. The Calvan thread insert repair saves down time, money and is stronger due to the material being steel alloy instead of aluminum like the original threads.
Related Repair Articles and Specialty ToolsCalvan 38900 Ford Spark Plug Insert Kit - Triton SOHC Thread Repair Kit 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 thread repair kit. Pro-Vision Borescope - To help verify metal shavings are removed after drilling tapping etc. Ingersoll Rand Air Ratchet - A good quality air ratchet is recommended by Calvan for drilling, using the bit in the 38900 kit. TIME-SERT Ford Spark Plug Repair Kit - PN 5553 for DOHC InTech engines and many other Ford applications when used with the proper insert. 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. TIME-SERT 4212H for some 2008 and newer 3 Valve engines with "pencil plugs" 12x1.25mm. Below Covers 04 & up Different Ford Spark Plug Problems - Broken Spark Plugs & Porcelain Staying In Q: I'm looking for Ford Rotunda OTC tool number 303-1398 for removing the ceramic or porcelain part of the spark plug. Thanks, David
![]() A: The Rotunda 303-1398 pictured above, is an expensive specialty tool (Calvan low cost alternative is the CAL39200) that has pins that are loc-tited into the center of the broken porcelain and only can be used once.
There is another method though, instead of gluing "one use" pins, a tool manufacturer has a better solution, The LIS65600 DLT broken spark plug remover mentioned before can be used as a different option than the 303-1398 & the 303-1203. The Lisle 65600 Ford spark plug remover, pushes 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 recommend. 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 on the image below to go directly to the product listing.
Lisle LIS65600 DLT Automotive Specialty Tool
|