97 f150 Rough Running

[Musky_Madness]

97 F150 4.6L. 142,000k.

Truck will sometimes run rough when first started or when I sit at a stoplight or sometimes when I am driving 55-70. It almost feels as if its shivering for a quick second. I changed plugs with Autolite Double Platinums at 125,000 along with plug wires. Would they be bad already? I bought the replacement set at The mans mall. I ran Sea Foam through yesterday when I had my low fuel light on so it ran through quite heavily and eliminated the stop light part, but noticed today still jerks a bit at highway speeds lik

e something is missing. No codes thrown. My guess is wires but not an expert. Could it be the distributor?

[JosMN]

I had a 97 4.6 that did the same thing, but always had a cylinder misfire code. Turns out, when it would rain the water would leak through the hood seal (located behind the wipers, rear of the hood) and drip directly into the rear or 2nd to the rear cylinder, forgot what # it was. Took that seal off, put a little bead of urethene on the bottom side and snapped it back in. To cure the misfire, I put a little di-electric grease on the bottom of the boots to press out any water from the plug area and wham, misfire was gone.

[fishing tech]

I have been a ford tech for 26 years. I would run nothing but Motorcraft plugs and wires. I have seen way to many other brands that do not last with fords ignition system.

[JosMN]

Agreed, along with always a motorcraft oil filter!

[spearchucker]

Agreed, along with always a motorcraft oil filter!

I don't think the oil filter is going to make the truck run rough?

My F150 has done the same thing in the past, but it goes away. I changed out O2 sensors (because of a different problem) and I didn't have the problem near as often. Could be a sticky EGR too.

[JosMN]

Wasn't implying that at all, it's a completely different subject and doesnt have anything to do with the 4.6.

a lot of f-150's, mainly only the 5.4 have a knock at start up, morning is worse. The Motorcraft filter is the only filter that I have used that takes most or almost all of that away, along with running 5-20 mobil 1. It has something to do with the drain valve. Got the advice about the motorcraft filter years ago, and have always used them since. Believe me, at first I was like "ya right, the filter is going to make a difference", but it really did.

[spearchucker]

The Motorcraft filters have a silicon anti drain back valve. It helps the noise. Napa Gold, Wix, and Purolator have the same valve, but Motorcraft is the cheapest and a great filter.

[Musky_Madness]

Simple fix! I began digging into the spark plug wire and the second one I reached for, 2nd to front on passenger side was loose. It came right up, so I put dielectric grease on the boot and popped it back into place. Runs like her old self again.

[Jeremy airjer W]

Thanks for posting the fix!

It may not be a bad idea to pull out that plug and inspect it for either a burnt up end or carbon tracking. Same with the wire. You might save your self another headache in the future?