Rough running @1500rm & 45mph. Shakes & shudders

[08HybridOK]

So I thought I had it figured out, apparently not!

So a short while ago, it started leaking at the intake manifold crossover. Finally psyked myself up enough to DIY R&R. IT went good.

Get her all back to gather, seems fine; for a week or 2, then started acting up; best way I can describe it is, it's like driving on rumble strips; but only when maintaining 45-50ish (my speedo is off like +5%). Thought it was missing, and I know I got coolant in the #5 plug hole.

Just before swapping coil packs; I did a seafoam treatment (1/3 gas, oil & vacuum line) That made her choke, shudder & smoke. Test drove & it threw a CEL, #2 coil pack.

So I replaced all the coil packs (Cheap set off Amazon for $50 for the whole set vs $50 ea!). Test drove seemed fine.

Its been sitting a couple of weeks now; decided to drive it today. First 10 miles were good; but then it started the rumble strip again, only when trying to maintain 45-50 & ~1500RPM. I think it might be doing it at 1500rpm & other speeds; just can feel it the same. Does not do it in park. Seems to idle fine in park, no studering or choking.

I have not yet changed the plugs; but only have like 86K so far.

Any other ideas?

Oh, & I'm original owner, this is her first engine problem.

 

[bedrck46]

would be nice if you posted year and eng information

 

[08HybridOK]

would be nice if you posted year and eng information

Humm? Thought it was in my sig!

2000 5.4

Oh and don't assume anything. I'm a youtube mechanic. All I did was unbolt the parts to get the manifold out; spray carb cleaner to clean up the mess, and reinstall & torque the new intake in. I didn't change the injector o-rings, or any other parts other than the coils.

 

[08HybridOK]

Well, following tips on another message I found w/similar issues; I 'reset' the computer, presumably by disconnecting the batt for 20+min.

That made it worse, its now shaking a little at idle, in park, can feel a slight shake accelerating from a stop; but smooth during heavy (normal) acceleration once moving.

Cruising at 50 there was a fast vibration; once it dropped into OD, the pulse slowed way down; but was much stronger. (Does that make any sense? from a drummers quick snare drum beat to a base drum)

Also changed the fuel filter after resetting; obviously no change.

 

[daoud el-massri]

Fuel pump maybe air getting around fuel injectors o2 cencer shot that is what happen o my 2000 4.6 shook out my front teeth . The mechanic cost me 1, 275.00 he told me it was the cats then he told me it was fuel pump then he said it was fuel injectors I got 2 from Auto Zone he charged me 85.00 to install the parts where only 28.00 dollars each will never deal with him again .

 

[bedrck46]

you had the intake off and also changed the coil packs That would have been a good time to change the plugs being they had 86k on them and your still having problems Suggest you change the plugs and see how it preforms As far as you tube I have seen some very good videos on there and I have seen some that I would class as comedy hour. Get yourself a good Ford workshop manual

Ford workshop manual on DVD can be obtained from seller "morpheousking" on e-bay cost about $10.00 much better than Clymer, Haynes or Chilton and also includes wiring diagrams

Don't waste your money on a Clymer, Haynes or Chilton Manual.
It is well worth the $10.00 just make sure you get the DVD for your year as the seller has different DVD's for different years

 

[08HybridOK]

I thought about changing the plugs, but I was not having any issues at that time. Just the coolant leak. I was worried they would break and drop pieces into the block.
I may try#5 as that's where I know I got coolant.

I do have a set of work shop manuals. Helpful, but I'm not confident in myself. I usually make things worse, as seen here, gone from a small leak to barely driveable.

Can I spray any old penetrating fluid down there to help?

 

[bedrck46]

by resetting the computer it then had to go through the relearn process and now its seeing things that have occurred since you changed cop's and intake install new plugs you can spray some penetrating fluid if you want just make sure you clean out the wells before you totally remove the old plugs Start by loosening the plug if you encounter any resistance turn the plug back in and use some more fluid let it soak for a bit and try again in and out helps if resistance is encountered, When you install new plugs torque them to specs Information should be in your workshop manuals. Also check fuel line pressure. when all is back together

 

[08HybridOK]

OK, got some time & warm weather today. Took the plunge and started to change plugs. Before I got started it threw the CEL, code #P0302, #2 cylinder misfire again.
So, I started there (again I thing #5 is the problem as thats where it fooded with coolant)
So let it warm up, sprayed some PB blaster down the hole & threw a ratchet on it right away, wasn't expecting it to budge; but it did! came right out! [WHEW!!] put some antiseize on the new plug, gaped to .054, and screwed it back in. Started up, still shaking at idle.
So on to #5, same steps & it too came right out! [2nd WHEW!!], put the new one in, started up, a smidge better; but still rockin' at idle.

So I took the new coil pack off #2, put an old one back on, and smooth! [So far, been here before!]

So knockin' on wood it's fixed, again!

Thanks for the help.

How many foot pounds should the plugs be at?

 

[bedrck46]

check your work shop manuals for the Torque specs I am sure they are in there