Help me think this out.

[uvbnhad]

Unfortunately it looks as though Ford is going to screw me over on the issue I've been going through based on the bull shit LL created. Now I have to fix the car and I'm going to let Paul do it but I'd like to get a feel for what I'm facing.

Symptoms:
-Rough idle but smoothes throughout RPM band.
-valve chattering
-slight oil smoke from from exhaust
-noticable power loss from low RPMs but less as RPMs/speed increases.

Noticeable things:
-no rod/piston knocking - leads me to think there isn't any "severe" internal damage
-idle smooths - makes me think it's nothing more than a valve(s) opening/closing correctly --> also makes me think Exhaust valve.

Follow me on this and see if it makes sense. Exhaust valve is not closing opening correctly thus not allowing the cylinder to make the normal power; creating a rough idle as the engine is then off-balance. As the rpms increase, the engine doesn't rely on each individual cylinder as much per se. The collective power of the entire engine is greater than each individual cylinder; i.e., inertia.

Any thoughts? Am I flawed in my thinking? Another cause?

[QWKSNKE]

ok I am thinking that if it is a valve situation like you mentioned, that it is going to be rough at all rpms or at least noticable. Has anyone had the valve covers off and looked at the valvetrain?

Has the car been put on scanner to check for codes?

[Sendero]

Symptoms:
-Rough idle but smoothes throughout RPM band.
-valve chattering
-slight oil smoke from from exhaust
-noticable power loss from low RPMs but less as RPMs/speed increases.


The slight oil smoke can be caused by an offroad pipe without cats. My car does it very slightly when I am on the loud pedal. The low RPM power loss could be from cylinder bleed, but I also wouldn't rule out the ignition.

Valve chatter? When? What RPM? While idling?


-idle smooths - makes me think it's nothing more than a valve(s) opening/closing correctly --> also makes me think Exhaust valve.


This has got me confused. Is there a rough idle and then it smooths out?


Has anyone had the valve covers off and looked at the valvetrain?


That would be a good start. But I'd do a leakdown test (which I'm sure Paul is going to do) in order to identify any problem cylinders. It is quite possible that your valvetrain is just messed up. While you are there, I'd check the cam timing too. It doesn't happen very often but your cams could have jumped time or be improperly timed altogether.

[Italian LX]

The slight oil smoke can be caused by an offroad pipe without cats. My car does it very slightly when I am on the loud pedal.
That's the understatement of the year... unless you fixed something since the last Dragon Run. :poke:

:D

[coupe]

Nathan: How can an offroad pipe cause oil to seep by either the valve guides or the rings?

[Italian LX]

Nathan: How can an offroad pipe cause oil to seep by either the valve guides or the rings?
I think he was refering to the fact that the cats no longer trap some of the the oil from the blow-by; not that it actually caused the problem. :shrug:

[Sendero]

I think he was refering to the fact that the cats no longer trap some of the the oil from the blow-by; not that it actually caused the problem. :shrug:

Thats what I mean.

If you got serious blowby (ie, busted valve stem seals or rings) then it sure won't be a "slight" oiling smoking issue.

[Scothew]

Mine smokes some when on it. Lil more than I would expect.. I dont think its a major problem.

[Sendero]

Mine smokes some when on it. Lil more than I would expect.. I dont think its a major problem.

Yours probably smokes as much as mine. I loose very little oil in a 4 month oil change rotation (less than a 1/8 of a quart). On our 4v's I believe most of the smoke is from being to rich rather than blowby.

[Scothew]

I dunno, Matt said it was blowing pretty good on the last dragon run. Guess holding 5500+ rpm in 2nd gear down the straights & through the whole 11mi run isnt good on the seals huh :jester:

[The Rock 326]

Mine smokes some when on it. Lil more than I would expect.. I dont think its a major problem.
:bs:







:jester:

[svopaul]

Driving it I am going to head in the direction of valvetrain related problem.....the miss never goes away but is more noticeable at idle.

My suspicion is that it was never repaired properly to begin with...only patched up. It is not uncommon for techs at dealerships to warranty parts and take them home with them....quite possible that if a set of heads was billed out on a previous invoice that the PI heads went home with the tech as a bonus and he patched something to make this one go away.....ofcourse that is all speculation but I don't see any other reason the car could have the same problem pop up 3 times :shrug:

Either way...initial tests will be run when ready and it's probably going to result in the heads coming off the car...Ofcourse this is all speculation until the hood goes up :D

[banditmwp]

I dunno, Matt said it was blowing pretty good on the last dragon run.
:yup:

But it was most noticeable when you were decelerating from 5k plus RPM's...

[AngelEyes]

I dunno, Matt said I was blowing pretty good on the last dragon run.
:eek: :popcorn: :ymca: