I have a 1998 F150 4.6L it's over heated a few times I just flushed it and put antifreeze cause the original owner had water in it. I also just installed new spark plugs and wires 2 weeks ago cause it was misfiring and now it feels like it's misfiring again, it's running rough and loss of power and there's alot of white smoke coming out. Aa soon as I fill it up with antifreeze a block later it would overheat. I got it towed home and from what I read and the fact that the dipstick was milky it seems like a blown head gasket is this something I can do myself or should I take it to a mechanic

 

Our trucks are hard to work on because so much of the engine is under the windshield. I suspect you need a mechanic. Another engine might be needed. Good Luck!

 

I'll echo Roadie.... the symptoms that you're expressing are not good...prolly better off searching for a replacement engine. Not that you couldn't rebuild this one, but most are not willing to inject that much investment into a older truck.

 

White smoke indicates that water (coolant) is getting into one or more of the combustion chambers. The fact that you have to keep adding coolant supports that. If someone has over heated the engine badly then that probably warped a head or possibly even cracked one and that is how water is getting into the CC. Pull the plugs and look at them and you'll most like be able to tell which cylinder has water in it. Most likely you're going to have to pull one or both heads and repair or replace them. IF you're lucky it may only be a blown head gasket but I suspect the worst. Doing a compression test on each cylinder should also pin point the problem.

 

If you pull the plugs, the one or ones that are real clean are the problem cylinders. The coolant steam cleans the plug.

The other thing is if you live where you need to have an emissions test it may fail after the engine repair. Antifreeze is tough on cats.

 

Been there, done that. I just had my engine rebuilt. Same symptoms. I had a bad head gasket, introducing water on cylinder #2. Paid a couple of guys $400 to pull and replace motor. I had 189k miles on 2003 heritage edition. This is the 100 year anniversary edition, I am the original owner, and am in process of bringing it back up to like new. Luv my truck and plan on keeping it for a long time. So, in total it was like $4200 bucks. Replaced all 02 sensors, water pump and a few other items that don't come to mind right now. I have an Android head unit on order and a bunch of stuff in wish list on amazon that I will get as funds come available.
BTW, for all the items I have on amazon, I checked the prices against auto zone. Everything was cheaper @ amazon (except for gear oil). I am prime member and everything was free shipping thru them or the seller. Transmission fluid and filter, shocks for the hood, mirror switch, headlight switch, odbII reader, brake pedal pad, fuel filter, leaf spring clips and a couple other things. Most of the prices were not significantly different, but total cost being over $500 it adds up, plus items are delivered to my door, and parts are motorcraft parts, not ***** knockoffs.

 

I TELLS YE DATS IT! WHY do members of this forum BELITTLE IND TALK DOWN TA NEW folk when they ask for help? It's happened TA me too.

 

i don't think any of the answers belittled anybody.

 

Wow dude, settle down! Either that or maybe you are to trying to be an MGD impersonator.

Please feel free to point out which post is talking down to the OP.