vincentAlpha

Hey All,

Been lurking about for a while (gotten lots of great tips). Was wondering if I could get some info from some of the other owners around here.

tl;dr if you own a 97' F150 with a 4.6L V8 did you find normal plugs or Ford's special plugs that have a habit of breaking when you replaced the stock ones?

Short story is that my engine has been misfiring on C8 for a little while and have gotten to the point where the next thing in line is to remove the spark plug and replace it. Unfortunately I've seen TSB 08-7-6; and while it doesn't list my truck's year my Haynes manual does indicate that these engines have the same issue. So while I'm happy to replace my own plugs under normal circumstances I really don't want to touch that bit if my engine is covered by the TSB (I'd just as soon take it to the dealer then rather than risk mucking up the head myself).

Long(er) story is that a few months back I had a misfire on C3, checked a few things and decided the easiest thing to start with was the maintenance that should have been done probably quite some time ago since I'm the 2nd owner and at this point I'm fairly certain the original owner didn't touch a thing on it except (hopefully) oil changes. This misfiring is really the only issues I've had with the motor so far and since I've owned it I've been learning and trying to keep on top of repairs and maintenance as best I can without wreaking the only vehicle I own. First went the plug wire and that seemed to do the trick for a couple weeks. Then C8 started misfiring and figured that having a new wire and an old wire on paired cylinders may have mucked up the coil or the coil was part of the problem all along and a bad wire was part of it too. Replaced it but still missing (and that coil looked like crap too I have to say, next order for parts is getting an extra coil for me to toss on as the other is probably as bad). So onto the spark plugs it would seem but as I mentioned above... not looking like a fun afternoon repair.

PS. Apologies to the mods if this should be in a sub somewhere. Feel free to move it as need be.

techrep

iTrader: (1)

The only plugs that are prone to breaking while removing are the 04-07 5.4l 3V.. that I am aware of..

vincentAlpha

Hmmm, looking into it a bit more it seems that the spark plug issue is down to the 3V not the 2V engines. Apparently I just have to worry about bad threads from the factory. Guess the Haynes manual I have must cover some of the 3V engines; either way I'll be doing it with the engine dead cold and using carb cleaner just in case. If anyone has any tips or advice I'd greatly appreciate it.

Jbrew

No bad threads from factory, where did you read that ?

The problem was with the torque spec from the factory. So all you have to concern yourself with is torquing them down properly. Then you won't have a problem.

BTW- Carb cleaner is like poison around these engines. Not sure what your planing to do with that, thought you should know.

vincentAlpha

TSB 07-21-2 (http://www.revbase.com/BBBMotor/TSb/...dPdf?id=139963):

"Some 1997-2008 vehicles equipped with a 4.6L 2V(...) engine and aluminum cylinder heads may experience a spark plug port with stripped or missing threads."

Guessing not as common an issue as may be the case or is this related to the spark plug blow-out issue I've heard of?

Jbrew

Yea that's just a repair TSB if your plugs become loose from improper torque or if you cross thread them. It's there to help you out.

vincentAlpha

Aaah, good to know. So all in all this is looking like replacing the plugs shouldn't be too painful, aside from C8 being right at the back anyway.

Also for the carb cleaner; was going to put some down the wells (at the time figured following the other TSB at least in part to cover all bases wouldn't hurt) since I'm pretty sure these plugs have been in there for all of the 160K miles that the truck has been on the road. Guessing just turning 1/4 turn and adding in some PB blaster or similar might be better then?

Jbrew

Nah, the plugs will come out fine dry. I wouldn't use anything as it can mix with oil in the crankcase.

With the plugs, things to remember. Just use the Motorcraft brand (not Autolite) and torque them to 28' lbs.

vincentAlpha

Huh I would have figured some sort of lubricant would be needed, seems most everything else I've take off or replaced benefited from it.

Will do on the plugs (already have the right ones), read that the ignition system can be a bit finicky about non-motorcraft parts, so everything else that I've replaced has remained Motorcraft, and so long as the prices at Rockauto on stock parts lets me beat no-name brand aftermarket (or whatever Canadian tire and the like sell up here, generally nothing I hear much of) I'll be keeping to Motorcraft.

Thanks for the advice/help!

screamineagle

This^^^. No need to spray contaminates into the plug wells, these are one piece plugs and will come out with no issue. Like Jbrew said, be sure to torque to 28 ft lbs and you will have no problems