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Old June 24th 05, 10:18 PM
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Internal noises that sound like lower end problems MUST be diagnosed ASAP to
prevent further catastrophic damage. When a crankshaft bearing fails it
usually takes a lot with it. DO NOT DRIVE THIS CAR.

Read what the others have said here.
Put the car on some planks to give yourself some clearance to work under
front. Chock the wheels, you will be doing a lot of running in neutral and
your parking brake can fail.
Check the easy stuff first, engine and accessory and exhaust mounts.
Install a real oil pressure test gauge, position it so you can read it as
you start the motor.
Make a test log to record some after start tests.
Have a real good listen to the motor, try to determine the source location
of any noises, if you have knowledgeable friends get their help to listen.
Piston and crank failures have pretty distinct sounds, they are usually very
sharp and vary substantially when engine speed changes. They even sound
expensive. Write down the results of following tests.

Start engine and run @ idle, observe when the oil idiot light goes out and
how long it takes for the engine oil pressure to build and what is max @
idle & 1000 & 1500 @ 2000 rpm

Blip the throttle and listen for internal noise with a mechanics diaphragm
probe stethoscope (a piece of hose works but is harder to interpret).
Listen particularly for sounds on rapidly closing the throttle, this is when
the con rod bearings are unloaded and can float loosely, pistons are also
free to slap and these sounds are often difficult to distinguish. Record
what the oil pressure does as you vary the engine speed and how fast it
drops to idle pressure. (rapid pressure drop can indicate excessive bearing
clearance)

Examine the plugs and do a compression check.

Have a look inside the valve cover, failed valve train can make strange
noises into the manifolds, drop in power is not always large. Use some
plastic to catch the oil spray and have a look while the engine is running,
use your hose to listen to each valve tip.

Drain the oil into a clean container. Allow to settle and check for coolant
as you strain the oil through a cloth, check with a magnet and for other
particles of metal or other.

Cut apart the oil filter (use a pipe cutter or a cold chisel, do not use a
saw or grinder) and wash the paper in a clean can of solvent. Examine the
filter with a magnifying glass. Run the solvent though a coffee filter and
check for particles.

Review your results and make sure you have not overlooked something easy.

Remove the oil pan (you may need to raise the motor?) and check the crank
assembly and piston undersides, rotate the crank and inspect piston skirts
and cylinder bores with a strong light.. Check for loose bolts. Remove
bearing caps to check bearing wear surface and crankshaft for smoothness and
color. Check bearing clearances with plastigage.

Faulty assembly is always suspect in crank failures. Were the con rod bolts
removed? Did YOU check the bearing clearances at assembly? How? Did you
torque the bolts dry? or with Loctite? Did you add a litle for mother?
Faulty machining many be the cause of the failure but the assembler usually
carries the can, consider yourself lucky if a failed bearing does not damage
the crank.

Just my .02, Good luck

"Nobody" > wrote in message
...
> Hello:
>
> I have a 1996 SW2 that had low compression and high oil consumption. Last
> summer, I pulled the engine, tore it down and sent the block, crank, head,
> etc off to a machine shop. It came back with a rebuild kit, bored out

block,
> rebuilt head, turned crank, etc. It took a few nights to put it back
> together, but it when I put it back in, it started on the first try. It

had
> good compression and the oil consumption stopped. As a side note, I

replaced
> every sensor, gasket, etc. that I could find on the engine before
> reinstalling it.
>
> A few weeks later, I noticed the head gasket leaking antifreeze most of

the
> way around. I took the head off again and went to the dealer and bought

head
> gasket and new head bolts. I noticed the dealer gasket was thicker than

the
> rebuild kit one and seemed to have an orange "rubber band" running

through
> it. I reinstalled the head and other stuff and the leaks were fixed. It

was
> running as good as new.
>
> Now, its a year later and my wife mentioned a "knocking" noise. I took it
> for a drive the other day and sure enough, I thought the engine was

falling
> apart. It has good performance, good milage, isn't using any oil, no
> antifreeze missing from the coolant tank and no trouble codes set. But,

when
> cruising, it knocks so loud I think it's falling apart. Under load, the
> noise completely disappears. Under idle it's fine, but rev the engine to
> about 1200 rpm and it shows up.
>
> Should I be worried? Any suggestions on where to start? Is it possible the
> head gasket is leaking again?
>
> A friend suggested a problem with the lifters. Another said the pistons

were
> loose. How would I know? By the way, I bought a new torque wrench for this
> project and carefully observed the specs and procedures in two different
> manuals.
>
> Thanks in advance.
>
> You can email me directly at
>
>



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