G
God
why does my 02 cruiser make funny noises when its really cold?
R
Rick Merrill
God said:
Funny "ha ha" or funny "peculiar"? (That's how my mother always
replied to such questions.)
Does the sound continue after the car is warmed up? - RM
P
Punch
God said:
are you referring to the diesel sound when you first start it?
H
Hans Mücke
God said:
My 02 sounds a little "rougher" when it`s cold, but after 1 or 2 miles ...
everything is fine ...
S
Sid Wood
My PT (2002 with 5-speed in southwestern Ontario) has made diesel-likePunch said:
noises since day one.
I have requested the service manager at my dealership to include my comments
with the vehicle's maintenance history; that is, I will not be surprised
when the engine dies prematurely.
OTOH, it has 55,000 Km so far and has never skipped a beat, summer or
winter, including pulling a tent trailer to Nova Scotia and back.
YMMV.
S
Steve
Sid said:
Its not a problem, just a case of modern pistons that expand more
slowly. GM has some real problems with piston slap in their cars- things
like increased oil consumption.
J
James C. Reeves
| why does my 02 cruiser make funny noises when its really cold?
|
|
Never had a car in 30 years that didn't sound and act "funny" when 1st starting
out in very cold weather. stiff, noisy, etc.
|
|
Never had a car in 30 years that didn't sound and act "funny" when 1st starting
out in very cold weather. stiff, noisy, etc.
B
Bill Putney
Steve said:
Some late model Subarus are also plagued by piston slap. Apparently
some of the marketing pressures (mileage? weight? power? emissions?) are
causing the piston design parameters (skirt length to diameter ratio) to
be pushed to the low end of acceptable limits - another case of creating
a new problem to solve a perceived older one.
Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")
S
Steve
Bill said:
Yep. I just had a first-hand example of how demanding hypereutectic
pistons can be, unfortunately. Lucky me.
The idea is that the alloy expands less with heating than traditional
eutectic or hypoeutectic alloy cast pistons (and WAY less than forged
pistons), and this allows the piston clearnace to be set very small for
tight sealing, which not only reduces emissions but helps fuel
efficiency too. In addition, the piston pins can be centered rather than
offset. They're normally offset in productin engines to provide a small
force that keeps the piston "cocked" to one side in the bore and
prevents it slapping around, but this adds friction. And then, as you
mentioned, skirts are shortened to FURTHER reduce friction. I think any
one of those ideas is fine, and maybe 2 of the 3 together would work in
mass production. Certainly you make all 3 work together in a custom
engine (so I hear
), but it may just be too much to expect for massproduction right now.
S
Steve
James said:
Old cars don't, they didn't have hypereutectic pistons with short skirts
and ultra-thin ring lands. Detroit spent the 30s and 40s solving all
those problems with things like T-slotted pistons, cam-ground pistons,
strut-reinforced cast cam-ground pistons, offset piston pins, and
autothermic pistons. But in the search for a little less friction and a
little tighter sealing, hypereutectic pistons with ultra-short skirts
are now popular and they rattle like a can of lead shot when they're cold.
M
mic canic
you oughta hear the funny noises my wife makes when she is cold
G
Geoff
Old cars don't, they didn't have hypereutectic pistons with short skirts
At -5F, don't matter what's under the hood, it will sound a little weird
until it warms a little.
--Geoff
At -5F, don't matter what's under the hood, it will sound a little weird
until it warms a little.
--Geoff