2nd blown spark plug
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2nd blown spark plug
I just blew a second spark plug ont he aluminum head of the 4.6L 2002 V8 explorer engine. This is completely unacceptable, has anyone here had this problem? Has anyone here sued Ford? They claim theres no problem with the engine, but the replacement head has 3 times the number of threads. This is my primary vehicle, I'm stranded and I cant even fidn someone willing to use a t-sert. Does anyone know what part I need to t-sert these threads?? Where can I order the t-serts? Has anyone done this on a cylinder head? I could really use some input on this guys.
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I blew a spark plug out of the cylinder head, its a very common problem on this particular engine. Timesert sells an "unapproved by ford" fix that involves reaming out the hole and screwing in the insert. Ive been told this is very easy and doesnt end up causing a lot of problems, but I'm concerned because its the very rear passenger side plug thats right next to the firewall. This means that I cant see down into the hole without a mirror and have limited clearance for a ratchet. I have no air tools here so I'm going to be using a straight hand ratchet, so I'm hoping although it will take a while, I'll still be able to do it. If anyone has done one of these, especially on one of these rear plugs, I could use any pointers you may have.
Fleet Owner
Joined: Mar 2003
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From: Blue Hill Township
For the F-Series, Expedition, and vans, the problem with the plugs blowing out of the heads lies in the few threads in addition to the ECU programming. When you go WOT, the trucks tend to stay in closed loop 60 seconds depending on the vehicle. This means that the truck is trying to achieve a 14.7:1 AFR under full load at WOT. Can anyone say detonation?
The electrode on the plug is usually closed when they blow. This tells me that the cylinder pressures spiked due to detonation and a lean condition while under load hence causing the plug to eject itself from the head.
Supposedly the Explorers, Mustangs, Crown-Vics, etc do not have this flaw in the programming so I am not sure what caused your truck to go lean like that, but the cause is usually high cylinder pressures or faulty plug installation.
The electrode on the plug is usually closed when they blow. This tells me that the cylinder pressures spiked due to detonation and a lean condition while under load hence causing the plug to eject itself from the head.
Supposedly the Explorers, Mustangs, Crown-Vics, etc do not have this flaw in the programming so I am not sure what caused your truck to go lean like that, but the cause is usually high cylinder pressures or faulty plug installation.
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do a search for the timesert thread. someone had given a link to very good instructions with pictures. If you have the tools it seems simple but since you blew #4? spark plug that will be a pain. You said this is your second blown plug. what was done to repair the first one? I think 03 and newer heads have more threads.
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The first one that blew was repaired by a some guy in a truck I found in rural VA who had bought the Timesert kit and was making a killing by doing just Ford blown plugs. I replaced the plugs myself, torqued them with a torque wrench according to the service manual. Ive installed literally hundreds of plugs, this is not improper installation. Ive been getting no detonation even WOT, and my plug electrode wasnt closed when I took the plug out. Theres too few threads on this head especially with the soft aluminum. Sorry guys, but this may be my last Ford. This is completely unacceptable. I'm going to sell the timesert tools on ebay when I get rid of the car and buy a toyota sequoiah...
Fleet Owner
Joined: Mar 2003
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From: Blue Hill Township
Did you use anti-sieze on them? What did you torque them to? There hasn't really been a problem with plugs blowing out in any of the non truck (f series, expedition, etc) motors that wasn't caused by some kind of error in installation. They are picky motors when it comes to the spark plug installation due to the 4 threads, but they should be plenty to hold the plug in when done properly.
Last edited by MisterCMK; May 1, 2007 at 11:09 PM.
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johns, no its not normally the end of teh world, but on this engine with only 4 soft aluminum threads, you have to get it just right, and even then it can fail regularly. Its flat out a very poor design, theres no way around it. I talked to the guy at timesert that makes these kits. The engineer there told me they sell thousands of tehse kits designed specifically for these engines (the only customized kit they sell by the way) - anyone who still thinks that its a result of improper installtion is ignoring the facts.