What were the worst years/models? My research on the 'net seems to indicate the 5.4's were by far the worst in the F series trucks. I just bought a 2004 150 heritage with the 4.6. Do i have an issue here to worry about? I originally thought (before researching it) that this was an early to mid 90's problem. My truck has the 2 valve engine, not the newer 3 valve version. As always, TIA!
Ford modular V-8 spark plug ejection
- Thread starter HM12460
- Start date
- Status
OVERKILL
$100 Site Donor 2021
Issue covers the entire 2V line-up as far as I recall. The 5.4L's typically got heavier service, and that's why they are more known for it. The heads are essentially identical between the 5.4L and 4.6L.
If the plugs are changed with the RIGHT plugs and installed CORRECTLY, the issue is far less likely to occur. Loose plugs, with sparse threads in holes that already have few threads to begin with=ejecting plugs.
The newer plugs have a fully threaded-shank from what I understand (my '02 had them) that greatly reduces the likelihood of it happening.
I did mine in my driveway. It is not a very quick process, taking several hours.
If the plugs are changed with the RIGHT plugs and installed CORRECTLY, the issue is far less likely to occur. Loose plugs, with sparse threads in holes that already have few threads to begin with=ejecting plugs.
The newer plugs have a fully threaded-shank from what I understand (my '02 had them) that greatly reduces the likelihood of it happening.
I did mine in my driveway. It is not a very quick process, taking several hours.
The heads that have the full length threads spit the plugs out the least. The best way to check is to pull a plug and try to count the threads in the head, you want to see 8-9 threads.
The major problems were in the earlier 4.6 & 5.4's. The problem was with the number of threads in the heads and on the plugs. They changed the number of threads mid 03 if I remember correctly.
In my 02GT I've always used the MC plugs with more threads than the ones originally used.
Most of the time the problems pop up after a set of new plugs had been put in. People don't wait till the heads are 100% cold, don't use some anti seize, don't torque them down properly. Or,all of the above. Then after a while the plugs will start to loosen up. It'll sound like an exhaust leak at first, then after a while it'll shoot the plug out and take the threads with it.
In my 02GT I've always used the MC plugs with more threads than the ones originally used.
Most of the time the problems pop up after a set of new plugs had been put in. People don't wait till the heads are 100% cold, don't use some anti seize, don't torque them down properly. Or,all of the above. Then after a while the plugs will start to loosen up. It'll sound like an exhaust leak at first, then after a while it'll shoot the plug out and take the threads with it.
Originally Posted By: AdRock
The major problems were in the earlier 4.6 & 5.4's. The problem was with the number of threads in the heads and on the plugs. They changed the number of threads mid 03 if I remember correctly.
In my 02GT I've always used the MC plugs with more threads than the ones originally used.
Most of the time the problems pop up after a set of new plugs had been put in. People don't wait till the heads are 100% cold, don't use some anti seize, don't torque them down properly. Or,all of the above. Then after a while the plugs will start to loosen up. It'll sound like an exhaust leak at first, then after a while it'll shoot the plug out and take the threads with it.
The major problems were in the earlier 4.6 & 5.4's. The problem was with the number of threads in the heads and on the plugs. They changed the number of threads mid 03 if I remember correctly.
In my 02GT I've always used the MC plugs with more threads than the ones originally used.
Most of the time the problems pop up after a set of new plugs had been put in. People don't wait till the heads are 100% cold, don't use some anti seize, don't torque them down properly. Or,all of the above. Then after a while the plugs will start to loosen up. It'll sound like an exhaust leak at first, then after a while it'll shoot the plug out and take the threads with it.
The 04+ plugs tend to have a different problem, they get stuck. The OEM spark plugs are 2 piece and they come apart with the bottom part getting stuck in the head.
3-valve 5.4 L and 6.8 L engines built before 10/9/07 and 3-valve 4.6 Ls built before 11/30/07 found in many 2004-2008 Ford, Lincoln, and Mercury vehicles have an issue with difficult to remove spark plugs which can cause part of the spark plug to become seized in the cylinder head. Ford acknowledges this issue in TSB 08-7-6 as well as earlier TSB's. Ford's TSB does not state that this issue is caused by owner neglect. The TSB provides a special procedure for spark plug removal on these engines. For situations where the spark plug has broken in the head, Ford distributes multiple special tools for removing the seized portion of the plug. The multiple procedures required for the different cases/situations of plugs seized in these engines are explained in the TSB. This repair is covered for vehicles under warranty, however, the Ford recommended spark plug service interval extends beyond the duration of the New Vehicle Limited Warranty.
3-valve 5.4 L and 6.8 L engines built before 10/9/07 and 3-valve 4.6 Ls built before 11/30/07 found in many 2004-2008 Ford, Lincoln, and Mercury vehicles have an issue with difficult to remove spark plugs which can cause part of the spark plug to become seized in the cylinder head. Ford acknowledges this issue in TSB 08-7-6 as well as earlier TSB's. Ford's TSB does not state that this issue is caused by owner neglect. The TSB provides a special procedure for spark plug removal on these engines. For situations where the spark plug has broken in the head, Ford distributes multiple special tools for removing the seized portion of the plug. The multiple procedures required for the different cases/situations of plugs seized in these engines are explained in the TSB. This repair is covered for vehicles under warranty, however, the Ford recommended spark plug service interval extends beyond the duration of the New Vehicle Limited Warranty.
I have a 2002 F-150 with the 4.6. From what I 've read over the year's it wasn't until model year 2003 that the lack of spark plug threads in the heads was "resolved". Of course some early 2003 heads could still lack the threads until they ran out of 2002 heads used on 2003 trucks. I loosened my plugs without removing them and re-torqued them. So far so good at about 49,000 miles. This coming summer I'm going to replace them.
Whimsey
Whimsey
I hope it's fixed, would suck if that happened to our expedition with it's 4.6L.
I've seen trucks with 80,000 miles spit out the OE plugs.
The problem with these heads is that Ford started out with only two threads in the head for the plug.They then went with I think,four threads.The heads can be fixed with inserts but it is best to have it done by a mechanic because it is a hard job and has to be done right.There is little if any room for error because of the way that the repair has to be done,if it isnt correct,you are in trouble.
a co has been making engines for how many years? and then all of a sudden they dont know how to do spark plugs? whats wrong with this picture?
Originally Posted By: morris
a co has been making engines for how many years? and then all of a sudden they dont know how to do spark plugs? whats wrong with this picture?
Engineers who think CAD is a cool way to cut the quality out of a product.
a co has been making engines for how many years? and then all of a sudden they dont know how to do spark plugs? whats wrong with this picture?
Engineers who think CAD is a cool way to cut the quality out of a product.
- Status
Similar threads
