Abnormal Engine Vibration Explorer LTD 2004 V6

Hello All -

I've had this vehicle since June of last year. I've been very pleased
with it so far.

It's recently developed a strong engine vibration that occurs during
idle (park, drive or neutral). If (while in park/neutral) I blip the
throttle I get slow rpm response with a bit of a blurp (for lack of
better word) post throttle release. It almost sounds like a highly
muffled back-fire.

The engine appears to run normally while driving. I've detected no
signs of abnormal vibration during light or high throttle and there's
no correlation with the AC being on/off.

The dealer replaced all the injectors and alternator. The computer
shows no fault-error codes. The dealer techs are stumped.

Anyone else experience the same conditions?

>The dealer techs are stumped.

They shouldn't be.

I am guessing that since the dealer has done injectors and alternator that
they have put the car on the engine analyzer and checked all the electronics
and see no issues. Plugs, wires, coil packs are good, etc.

So, if that is the case, put a vacuum gauge on it after it warms up and check
the readings. You want to see a high steady vacuum on a new engine. Blips
on the gauge, a wandering gauge needle, low vacuum readings, etc indicate
probable internal engine issues. An experienced mechanic and a vacuum gauge
can tell you a lot.

Also try running a compression check and a cylinder power drop test where
they cut out each cylinder one by one, and watch the rpm drop to see which
cylinders are weak.

Guessing you are looking for an internal engine problem. I have heard of one
V6 that had similar bad idle issues and bad throttle response, and the timing
chain tensioners were bad. That person was chasing electronics all over the
place and the vacuum gauge showed an internal problem right away.

You could also have a stuck/ weak hydraulic lifter, broken rocker arm, or
other issues. Some of those are pretty darn unlikely, but if the external
stuff checks out, its time to think internal.

Post back when you get this figured out. Always fun to see if I got anywhere
close to the real issue or if I get to wear the class dunce hat for awhile.

Thanks for your replay and analysis ross. Ford sent one of their roving
engineers to look at the vehicle. The engineer determined that the
engine is "out of balance" and is suffering some kind of internal
problem. I wasn't present when they looked at the engine so I don't
know what kind of tests were performed.

The engineer said they would have to dismantle the engine to
investigate. As a result of this I'm getting a new engine! The dealer
has ordered a new engine. For now they've given me back the car until a
new engine arrives and they say it's "safe" to drive. Needless to say,
I won't be driving this vehicle very far as I would hate for it to die
on me or my wife.

When all is said and done I'm getting a vehicle with 0 miles on the
engine.

Would anyone know how long it takes to perform an engine install? How
many miles would the engine need to run to break it in? How should I
negotiate to get a loaner car when they do peform the work?

Thanks for your advice.

my engine was replaced at about 16k miles because of some knocking when
cold.

i was very reluctant about changing out the engine-the original engine was
fine once the knocks went away.

however, the changeout went smoothly and i haven't had any problems with new
engine

2000 LTD 5.0 v8 2wd
67000miles

> wrote in message
oups.com...
Thanks for your replay and analysis ross. Ford sent one of their roving
engineers to look at the vehicle. The engineer determined that the
engine is "out of balance" and is suffering some kind of internal
problem. I wasn't present when they looked at the engine so I don't
know what kind of tests were performed.

The engineer said they would have to dismantle the engine to
investigate. As a result of this I'm getting a new engine! The dealer
has ordered a new engine. For now they've given me back the car until a
new engine arrives and they say it's "safe" to drive. Needless to say,
I won't be driving this vehicle very far as I would hate for it to die
on me or my wife.

When all is said and done I'm getting a vehicle with 0 miles on the
engine.

Would anyone know how long it takes to perform an engine install? How
many miles would the engine need to run to break it in? How should I
negotiate to get a loaner car when they do peform the work?

Thanks for your advice.