plugs blowing out of heads, 4.6vs5.4

[mnstang]

i know the 5.4s blow spark plugs out of heads sometimes.

i don't hear it alot happening on the 4.6, is it just as common? specifically f150's.

[Sweet35th]

The 5.4Ls and the 4.6Ls share the same cylinder head. The biggest issue with plug blow out is not the head itself, its in the PCM tunning.

Factory 5.4Ls and 6.8Ls in trucks (the most prone for blowing out plugs) are programed from the factory to stay in closed loop at WOT for a period of time....the 6.8Ls stay in closed loop at WOT nearly indefinatly. Most 6.8Ls ping themselfs to death with a trailer behind them, and the 5.4Ls in trucks arnt much differanct, they stay in closed loop for some calibations over 60 seconds...That means at full load wide open throttle, the PCM is comanding a 14.7:1 a/f ratio!!!!! its nuts!!!.

If you look at the spark plug that is typicaly still stick to the coil of the a truck that blows a plug out, you will typicaly see its electrode is closed (the ground strap hitting the center electrode), this is from pressure in the cylinder spiking increadibly high, from detonation!!!

Mustangs, crown victoris, marquies, explorers ect, do not have this closed loop delay at WOT, this is why such vehicles do not blow plugs..

Not too add comanding 14.7:1 at WOT just kills power... I recently tuned a 6.8L V10 truck that picked up nearly 40rwtq from just the tune, correcting the a/f. The truck actualy picked up 1mpg while pulling a trailer because it did not have to downshift so much while hitting hills. Now 1mpg may not sound like alot, but with a 38 gallon fuel tank, thats nearly 40 more miles on a tank, combined with more power to pull a trailer, it makes a big differance.

[2 beer]

so you can tune them so it goes into open loop sooner?

[mnstang]

so do the 4.6s (in trucks) blow plugs out too?

[SVT5LITER]

Great info Casey. Have you guys done any 5.3 tunes at all?

[mnstang]

Great info Casey. Have you guys done any 5.3 tunes at all?

i'm trying to figure out if i need to swap in my 5.0l aka 'ol reliable' into my new rig.

[2 beer]

if it blows out a plug its not to bad of a fix

[CleanLX]

i'm trying to figure out if i need to swap in my 5.0l aka 'ol reliable' into my new rig.

Sick!!

[2 beer]

Dont put a 5.0 in a new truck at least do a 5.8

[MisterCMK]

How much would it cost to have a 2000 Expedition with the 5.4L tuned?

[Sweet35th]

i'm trying to figure out if i need to swap in my 5.0l aka 'ol reliable' into my new rig.

What year is the truck, and what is it? If you get me the PCM calibration code, I can tell you how long the wide open throttle fuel delay is.

[Sweet35th]

so do the 4.6s (in trucks) blow plugs out too?

We never saw too many with them, but 5.4Ls and 6.8Ls are a much more comon engine in the trucks.

[Sweet35th]

How much would it cost to have a 2000 Expedition with the 5.4L tuned?

$500 for a dyno tune, and $300 for a basic tune correcting for wide open throttle fuel delay, some shift pressures, shift points, ect ect.

[dynotune]

The 5.4Ls and the 4.6Ls share the same cylinder head. The biggest issue with plug blow out is not the head itself, its in the PCM tunning.

Factory 5.4Ls and 6.8Ls in trucks (the most prone for blowing out plugs) are programed from the factory to stay in closed loop at WOT for a period of time....the 6.8Ls stay in closed loop at WOT nearly indefinatly. Most 6.8Ls ping themselfs to death with a trailer behind them, and the 5.4Ls in trucks arnt much differanct, they stay in closed loop for some calibations over 60 seconds...That means at full load wide open throttle, the PCM is comanding a 14.7:1 a/f ratio!!!!! its nuts!!!.

If you look at the spark plug that is typicaly still stick to the coil of the a truck that blows a plug out, you will typicaly see its electrode is closed (the ground strap hitting the center electrode), this is from pressure in the cylinder spiking increadibly high, from detonation!!!

Mustangs, crown victoris, marquies, explorers ect, do not have this closed loop delay at WOT, this is why such vehicles do not blow plugs..

Not too add comanding 14.7:1 at WOT just kills power... I recently tuned a 6.8L V10 truck that picked up nearly 40rwtq from just the tune, correcting the a/f. The truck actualy picked up 1mpg while pulling a trailer because it did not have to downshift so much while hitting hills. Now 1mpg may not sound like alot, but with a 38 gallon fuel tank, thats nearly 40 more miles on a tank, combined with more power to pull a trailer, it makes a big differance

This partially true, but not completely. There are heads w/ 10 threads and heads with only 4. This is why ford has a newer style replacement head for the older lightnings. The WOT delay is true, although MANY manufacturers have been using it for years, and it works fine (for the most part) This is a fuel economy saver as when towing your are not using all the fuel. Most customers that haul "heavier" loads will notice an increase in economy because the vehicle has enough power to stay in OD, they no longer need to downshift (after programming). Sometimes (on lighter loads such as boats, sled trailers, etc) the customer will lose economy because they go WOT and don't need the power (after programming). GM has a 60 second delay on ALL of its trucks with 8 lug hubs, and they aren't blowing plugs out. You do generally pick up good horsepower in removing this, but ford has 3 different timing tables and if you don't correct them before you remove this, you will
A. have problems (pinging) if you don't correct it and fix the timing tables
B have a lack of power if you don't fix the timing tables after unlocking this

I have tuned hundreds of these trucks, and I guess that has been my experience...
I agree the higher cyl pressure isn't helping the plug blowout, but it is NOT the cause of the problem. Ford would have had a PCM flash to fix the plug blowout if that was the case (it would save alot of labor in removing cabs to replace cylinder heads for free under warranty )

just my $.02

[I Tried]

This partially true, but not completely. There are heads w/ 10 threads and heads with only 4. This is why ford has a newer style replacement head for the older lightnings. The WOT delay is true, although MANY manufacturers have been using it for years, and it works fine (for the most part) This is a fuel economy saver as when towing your are not using all the fuel. Most customers that haul "heavier" loads will notice an increase in economy because the vehicle has enough power to stay in OD, they no longer need to downshift (after programming). Sometimes (on lighter loads such as boats, sled trailers, etc) the customer will lose economy because they go WOT and don't need the power (after programming). GM has a 60 second delay on ALL of its trucks with 8 lug hubs, and they aren't blowing plugs out. You do generally pick up good horsepower in removing this, but ford has 3 different timing tables and if you don't correct them before you remove this, you will
A. have problems (pinging) if you don't correct it and fix the timing tables
B have a lack of power if you don't fix the timing tables after unlocking this

I have tuned hundreds of these trucks, and I guess that has been my experience...
I agree the higher cyl pressure isn't helping the plug blowout, but it is NOT the cause of the problem. Ford would have had a PCM flash to fix the plug blowout if that was the case (it would save alot of labor in removing cabs to replace cylinder heads for free under warranty )

just my $.02

Verry well said, If the problem of spark plugs could be fixed by just changing the tune Ford would have had a recall so fast it would make your head spin. I have replaced about a dozen heads on all 3 of the motors under warranty and I always fix the old head and sell it if ford dosent call it back. It is a easy fix if they blow out. When doing the head replacement after blow out I have to replace the head and all 8 or 10 spark plugs but no reflash for the tune??? Are the ford engineers missing something?? I have also owned 2 trucks with 5.4's and 2 v10 super dutys and I have never had a detonation problem or spark plug problem.

Tim