So my truck has 162k with the 5.4. I just dropped another motor in it cause my original crapped out from blown gaskets an antifreeze mixed with oil everywhere makes for one hell of a nice mess. The new motor has 87k on it out of a 2000 f 150 just had to change the upper manifold. Took it out all day yesterday no problems, let it sit for an hour hopped back in it an its doing the same studdering shaking crap it did with the old motor. Checked the plugs cause that's the first thing I'm use to checking with these pos. no cel on but cyl 2 & 4 had a little oil on the coil boot an on top of the plugs. Didn't spill any oil putting it in, but when they delivered the motor they took the oil filler neck off so I did notice last night that I didn't get quite a complete seal when I put it back on with some rtv silicone. Valve covers aren't leaking. what else could be wrong besides those 2 plugs? Or could that have been it with that little bit of oil?

 

Are you sure the Oil feel isn't antifreeze. Pretty common to have intake manifolds seep antifreeze into the plug holes, especially if just changed.

Some of the pretty common issues beside manifold...pcv elbow leak, COP boot cracks, or MAF sensor.

Sometimes, driving it hard, will pull a code. Always a help.

 

Everything is brand new besides the maf sensor. I thought it was antifreeze at first. I like to use the orange antifreeze just simply cause my Audi I used to have an now my passst can only use the orange. But when I looked close it looked green not orange then wiped it down an it was def oil all yellowish brown. It was def misfiring last night cause at low speed she was good then mid range she sucked an foot matted no problem. But as soon as i let off her she up shifted and right back to crap. I only pulled cyl 2 & 4 and then 1 & 3. Pass side was the only screwed up side so far. Maybe if I give a little more info on what i discovered with motor b4 dropping her in. Pulled old plugs from it 3 of the plug bores had oil on top of the plugs don't remember which though, oil was drained but they left the filter which had fuel mixed in the oil that was in it. The upper manifold gasket was beat an you can tell it was pooling up fuel in both front cyl cause those exhaust ports were majorly clean an the others were not. In my opinion in looks like it was sitting in a river for 5 freaking years lol. But it cranked by hand nicely when I called my buddy I got it from at chuck & eddies used auto parts (junk yard) he told me it has a 6 month warranty that u need to put it in b4 they will warranty it. So I said as nicely as possible if I'm putting a guaranteed motor in my truck that I'm almost positive is screwed I'm shoving it very far up someone's a$$

 

Unfortunately I know it sucks, but that's the chance taken when dropping in a used motor, with no way to pre-test it.

 

I'm not sure if this is your misfire or not, but if the engine is sucking air around the filler neck (oor any place else) that hasn't gone through the MAF will confuse the fuel mixture. (You might have a pending P0171 and/or P0174 code in there.)

 

No cel was present but I did reseal it witg a good bead of epoxy then rtv. Epoxy to hold strong in place an then rtv to seal her up. I also swapped the coils an plugs that had fluid on them with the ones I checked on the other side. I drove it around yesterday in the snow storm we had an I didn't have any problems with her. So I honestly didn't think there was enough liquid to fowl them out. But can nvr be to sure and its always good to kick ideas around with others that know there **** too. A buddy of mine said when he did his the same thing happened because tightening everything down in freezing cold then engine gets warm an settles back to cold loosens **** up even it u might not have noticed the coil packs might have loosened up not being torqued all the way anymore. So if I don't have any further problems I'd gladly chalk it up to either a loose coil pack or as pdqford said it was sucking air threw the oil filler neck. I will keep posted if problems return, but thanx for shootin the **** with some ideas I appreciate it.