Help with 94 4.0 liter "valve clatter" and "ignition misfire/exhaust popping" noise fix

Hey everyone,

My 1994 Limited has an interesting problem/problems.

1) It sounds like there is noise in the valvetrain, cylinder 4 (drivers
side, closest to radiator). A "metallic clatter" sound can be heard all the
time (startup, driving, highway speed, etc.). At this point I do not know
if it might be a collapsed lifter, or a problem with a pushrod or rocker
arm. The motor runs "fine", but is very lacking in power, and does not have
a smooth idle or operation

2) The exhaust "pops" like a cylinder is misfiring, and the sound
coincides with the metallic sounds coming from the engine (i.e. the sounds
occur with the same timing and frequency).

3) The truck shudders quite a bit with "light throttle" at highway
speeds. Either backing off or accelerating harder reduces the amount of
shudder considerably (back to the "background vibration" that occurs even at
idle). I do not notice this at speeds less than 50k. It does seem to go
away if I shift from OD to Drive....but I don't know if that relates to the
RPM of the motor, or if it suggests a transmission issue. The car also
"clunks" into reverse, and I have read that U-joints may be the problem.
Could that relate to the shudder at highway speeds as well?


So far I have done the following:

-replaced spark plug wires and plugs (and yes, I wired the plugs correctly,
taking into account the weird order on the coil)

-removed, tested, and cleaned all fuel injectors to ensure fuel delivery is
occurring (replaced upper and lower fuel rail gasket at the same time)

-tested for spark (spark is very strong from wire to plug) in questionable
cylinder

-I have also cleaned the MAF and IAC a couple of times now to ensure they
are working properly.

-changed oil, ran 2 cans of "valve/lifter quieter" additive, then changed
oil 350 kms later and used 20w50 oil (no change in problems)

-had all tires rebalanced (they are quite new tires on all 4 wheels)


So I think that I have a valvetrain problem, and am wondering if improperly
opening valves is causing a misfire-like condition.

As far as I can tell (running engine with #4 spark plug removed) gas is
entering the combustion chamber (the air being expelled from the spark plug
hole reeked of fuel), and there is definitely adequate spark.


Sooooo.....the question is what to do next. I am thinking about pulling the
valve cover to see if something obvious is broken (I picked up a used rocker
shaft set and pushrods from a scrapyard just in case).

If the lifter is collapsed, I presume there will be lots of play between the
rocker arm and pushrod? If this is the case, can someone tell me
definitively if I have to pull the head or not to replace the lifter? The
AutoZone web manuals say no, but an article I read on a Ford website said
yes.

And any suggestions on cheap replacement lifters? Apparently they are
$70-90 EACH!!

I was told that "the lifters have a teflon cap that can fall out with age,
causing valve clatter, but this is just to be expected".....however even if
that is true (can anyone verify?) why does my motor run poorly and exhibit a
misfire condition?


Thanks in advance for any suggestions. And if I am way off....please point
me in the right direction.


Chris

Wow. And I was going to write a post called "Wierd Rattle." I have not
quite isolated the rattle on my '92 EB yet. It comes and goes. It sounds
like it's coming from under the valve cover above the #5(?) cylinder
(middle, driver side) or somewhere at the front of the engine. Mine sounds
like something metallic is hitting something that's going around. It is not
steady or rythmic. I was thinking it might be something that rotates (water
pump, AC pump, power steering pump etc) failing. Or maybe the timing chain
is coming apart or loose. I was (kinda) hoping that it was a broken spark
plug bouncing around in the cylinder and I could just get it out with a
magnet or something. My rattle occurs sometimes when it's idleling. It's
actually my wife's car and she said that it seemed to be running poorly as
though it was not running on all cylinders. The idle speed also seems to be
a bit low, or at least lower than it used to be.

Another possibility is that a mouse dragged something such as a screw under
the hood (yea, they build nests there) and it's just bouncing around. But
I'm never that lucky.

I also suspect the engine has a slight head gasket leak. It loses coolant
through the reservoir. It overfills the reservoir even though it is filled
to the proper level when cold. I replaced all of the hoses and the heater
core and had the radiator taken apart and cleaned. The intake manifold
gasket does not seem to be leaking. Can anyone tell me if a bad head gasket
can cause this?

The car has about 265K miles on it so I guess it's not unreasonable to
expect to have to start taking apart the engine about now.


"Chris" > wrote in message
...
> Hey everyone,
>
> My 1994 Limited has an interesting problem/problems.
>
> 1) It sounds like there is noise in the valvetrain, cylinder 4 (drivers
> side, closest to radiator). A "metallic clatter" sound can be heard all
the
> time

I just spent another couple of hours trying to isolate the rattle. I stuck
a length of garden hose up to my ear and listened all over the engine. It
seems to be loudest around that middle cylinder on the driver's side (#5?).
It was difficult to pin it down because it would stop sometimes. It didn't
seem to matter if the car was in gear or not, the brake on or not, or if it
was going uphill or downhill. It seemed to rattler more if I sped up the
engine but I couldn't tell for sure if it was rattling faster.

So, what might cause a sound like this? In my mind it sounds like perhaps
some 1/8" thick steel hitting against another chunk of steel and resonating
slightly. Broken valve stem maybe?

I just want to have some more clues before I go taking stuff apart.

Thanks.

On Mon, 4 Oct 2004 14:00:37 -0700, "Ulysses"
> wrote:

>I just spent another couple of hours trying to isolate the rattle. I stuck
>a length of garden hose up to my ear and listened all over the engine. It
>seems to be loudest around that middle cylinder on the driver's side (#5?).
>It was difficult to pin it down because it would stop sometimes. It didn't
>seem to matter if the car was in gear or not, the brake on or not, or if it
>was going uphill or downhill. It seemed to rattler more if I sped up the
>engine but I couldn't tell for sure if it was rattling faster.

Who was driving while you were in the engine compartment listening
with the hose?
Was the hood up or down? :-)


>
>So, what might cause a sound like this? In my mind it sounds like perhaps
>some 1/8" thick steel hitting against another chunk of steel and resonating
>slightly. Broken valve stem maybe?
>
>I just want to have some more clues before I go taking stuff apart.
>
>Thanks.
>

Bill Funk
Change "g" to "a"

About halfway down. I was also driving it. I'm very flexible.

I had the same problem with my 88 jeep. Took it to several garage's and
spent close to 900 dollars and got nothing till one day i started to
beet on things under the hood and found out it was the electronic egr
valve. I hope this helps you e-mail me if it dose.

randy

http://community.webtv.net/bama44r/MUDDRAGSANDMUDBOGS