O/T truck engine

[UncleBubb*IH]

I have been looking at trucks need some advice is the 4.6L v8 any good, I have heard some bad things about them. Same with the 4.2L.

 

[guido]

Hello uncleBubb*IH
I had a 1991 town car with that engine in it. That was the first year the came out with that engine. Biggest problem valve guides specially on the left head.I believe they came out with a better head as a replacement in 2002.
It would have a blue marking on it. It ran good for me but it used oil.
Guido.

 

[02XLT4X4]

They are a good engine, the only major problem is that the exhaust manifolds sometimes warp on the 97-03 engines. The newer 04+ trucks have an issue where the spark plugs can break off when you change them if you don't follow the proper procedure.

Overall they are a good engine, maybe a tad underpowered in a fullsize truck depending on what you are doing with it but should give you good service. For towing a 5.4 would be better, I love my 2002 2 valve 5.4 for power, they are pretty much a stroked 4.6 (with some other minor differences)

 

[dave guest]

Spark plugs can break and fall out no matter what you do. Not enough threads in the head. BTDT.

 

[02XLT4X4]

(quoted from post at 19:23:36 03/12/08) Spark plugs can break and fall out no matter what you do. Not enough threads in the head. BTDT.

Spark plugs do not break, they can strip out the threads in the aluminum head in the 97-mid 03 engines (they added more threads for the late 03's) and get blown out. For the V-8's it is more common in the 5.4's, it still happens but is much less common in the 4.6's. Really when you think of how many millions of them are out there it is pretty rare. The 6.8 V-10 in the 3/4 and one ton trucks is the worst at it. You can get steel inserts to fix it, and IMO it is what they should have done to start with, if it sounds like you have a lifter going out that is your plug loose and working against the threads and weakening them. If you catch it early you can usually just retighten it down the the factory torque and go, don't just by feel (very important)

The plugs can break off when you change them on the 04-08 engines, the plug blow out was totally eliminated. They have a long extension that is crimped on the plug to get down to the cumbustion chamber, and when stuff builds up between the extention and surrounding head it pulls the crimp apart. Ford has a TSB out on a proper technique to remove them that greatly reduces the chances of it happening. Champion has recently released a plug machined from one piece of metal that won't do this.