What happened:

My 4.6 has always been a pinger until I started running 91 octane (mid-grade in tx) in it which just about cleared up. Well I was in arkansas last friday and filled up at warmart and hit the mid-grade octane button.... well b4 I realized it i had 3/4 tank of 89 (mid-grade in arkansas). Well I didn't think nothing of it so I take off down the road and I noticed the truck is pinging like im running 12 octane in it or some shiz when climbing hills. Well I wanted to get out of arkansas (300 miles from tx) so I could get some 91 in her so I just kept going. Cruise was set on 75 and started to climb a hill so it downshifted and started pinging LOUD!! For about 2 seconds then dropped speed and started shaking , So i'm think *****!! Check engine light flashing, rough/low idle the whole bit, so I could basically tell she was runnin on 7 cylinders. She couldn't hold a steady speed over 50mph so I limped her back to tx to my mechanics house, #3 plug was fouled so I changed it twice and plug wire once..... NO BETTER. So I hook it up to a compression tester, like 20lbs of compression.

My theory:

I figure that the gas I got from wallyworld had some water in it so when my motor got really good and hot the water hit the carbon on the head and broke some of it loose. Which resulted in it getting lodged in the valve and burnt it up.

My Fix:

I've heard from numerous people, including my mechanic that the 4.6 is an intermangle mess of **** inside the engine and a valve/head job would cost me 1100$. Well I can get a 2002 4.6, 20k, romeo (what mine is) motor for 1150$. Includes starter, alternator... everything except for the ecu. The motor comes with a 30day warranty. Would I be better off just dropping this in and if so will everything bolt/plug in?? If I have to buy a programmer or chip to make the ecu read everything I guess I will.

Edit: I have already pulled the valve cover and all the rockers are in place. You can smell the unburned fuel coming out of the exhaust.

Sorry about the book


Thanks,
Mike

 

The 2002 has PI heads and uses COP ignition like the 5.4. It no longer uses an engine coolant temp sensor nor the intake manifold runner tuning valve so the wire harnesses are different. The 02 has PATS so the instrement cluster and ignition switch wiring is different. You could wire it to the 97 specs and get a chip or wire it to 02 specs and get a PCM and a chip to comp for COP ignition and PATS.

Regards

Jean Marc Chartier

 

I am sorry for your problems with your truck.

HOWEVER you started your post with a statement that your 4.6 was always a pinger. And instead of fixing it you chose to just drive it and put a bandaid on it with higher octane gas.

The gas from Wallyworld had nothing to do with your problems. I doubt you burned a valve. I would pay a competent modern mechanic to give you a diagnosis then have him do a carbon depletion service on your truck and replace all your plugs. wires, and coils. It will be a whole lot cheaper than a new engine or head.

 

Well now that I feel like a complete dumbass ..... So you think an engine flush would remedy the truck from running on seven cylinders? The coil pack,plug and wires were all replaced less than 8,000 miles ago. Have you guys ever seen this happend to a 4.6 before?

Edit: I through up no codes when put on the reader and this thing is SUCKING gas.


Thanks,
Mike

 

I didn't want you to feel like a dumba$$.

First off you need a proper diagnosis as to what is wrong. I didn't say engine flush I said a carbon depletion service. Both BG and Snap On have carbon depletion systems that are top notch. Go to their web sites and find a service station near you. For instance my local Ford Stealership uses the BG carbon depletion system.

You might not have codes set but you told us your cel was flashing which means a missfire. And you say it sucking gas what does that mean? Like I said have a properly trained modern mechanic perform a complete diagnosis. For instance the mechanic will be able to tell you if the injectors are putting too much gas out in relation to what is needed (Running rich)

Good luck and don't just throw parts at it.

 

Well that makes sense, I called around the local stealerships and they were like "we can change the oil and tranny fluid" . I guess that's what I get for living in the sticks. They want to charge me a minimum 3 hour service charge (at 75$/hour) to even look at it. That's why I'm trying to narrow it down as much as I can. Guess I'll hit up the yellow book.


Thanks,
Mike

 

Wish mine was that easy! Neighbor took my f-150, 4.6l into the dealer this weak. He and his nephew are top notch mechanics with Ford dealership. Had em' stumped for half a day until the "heavies" took alook at the engine after endless code reading. Damn number five cylinder!!! Took the compresssion and #5 was at 11%. Valve problem big time. I just got an estimate for the work, couldn't afford to fix it. Will need a new LH head with the valves, $1500 plus the 11 hours to pull the engine. Now I'm weighing a re-do engine from Ford with a 3 yr warranty versus $1500 in parts to fix this problem. Both are 11 hours labor!!! Runs fine but sputters around 1500 RPM or when lugging. Like I said, wish mine was as simple as yours .

KW

 

Well Mine has the same problem as yours (took it to the stealership today) and they gave me the same estimate. So the only problem I have now is swapping the 02motor into the 97 wiring rat nest. ANYBODY EVERY REPLACE A NON-PI MOTOR W/ A PI ONE???


Thanks,
Mike

 

Got out cheap, $1900, new left cylinder head, gaskets, oil, filter, and assorted stuff. 11 hours of labor, yikes.

Sucked a valve seat and damged the head was the final problem

 

I got a whole new engine in for 2200$


Edit: The engine I got is a 98... It don't kick down into passing gear when jump on it. Is there a "learning curve" for my ecu to read this new engine?


Mike