300M 3.5 serpentine belt replacement

I'd like to replace the serpentine belt on my 2000 300M.
Any special tools required ?
Kind of tight in there between the radiator and the front of the
engine.

How do you release the tensioner ?
All I can see from the top are mounting bolts.

Steve

 

What about the other belt?

Nope. 15mm combination wrench and a 13mm socket, swivel and
ratchet is all that's needed.

The tensioners are jack screws that pull the idlers tight, go at
them from the bottom.
Loosen the bolt that goes thru the center of the idler pulley
with the 15mm, back off the jack screws with the 13mm.

 

if you need more room you can take out the top of the radator support
panel
it is attached by 13mm and 10mm bolts but can be attached the front
bumper cover just pull it bac a little and support it with a6"2 by4

 

Remove the upper radiator crossmember for access - a little of a PITA,
but not as bad as it looks. It is advisable to replace the tensioner
pulleys (with bearings) periodically. They do go bad - usually making
noise before anything bad happens.

Also - I don't know if you considered this or not, but the timing belt
must be replaced around 105k miles - not an option unless you want to
risk damage to the engine (piston/valve interference). If that happens
to be due, consolidate some of the labor by doing the t-belt, t-belt
tnesioner, water pump, and the accessory belts and their tensioners at
the same time.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

hey bill with my makita impact driver i can have that off in 2 minutes

 

What is the purpose of this kind of setup? Do any V8 engines go through
this?

Ken

--
"Now Phoebe Snow direct can go
from thirty-third to Buffalo.
From Broadway bright the tubes run right
Into the Road of Anthracite"
Erie - Lackawanna

 

The car is a garage queen. Just cracked 20,000 miles on the odometer.
Shouldn't have to worry about the timing belt for another decade or so.
The wife puts about 3k miles per year on the car.

Steve

 

Ken,
Which particular aspects of "this setup" are you asking about? The way
the belts are tensioned, or the water pump being integrated into the
t-belt drive line, or the accessory belts being hard to get to?

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Bill,

Sorry for not specifying. What I should have asked is about Interference
Engines. Seems like there are plenty of them for six and four cylinder
engines. What is the reason for designing an engine like this?

Ken

--
"Now Phoebe Snow direct can go
from thirty-third to Buffalo.
From Broadway bright the tubes run right
Into the Road of Anthracite"
Erie - Lackawanna

 

Ken,

When an engine is designed, there are power gains to be made by
increasing compression ratio. One of the determining factors that goes
into achieving higher compression ratio is minimizing the volume (air
space) captured in the combustion chamber (defined as the space enclosed
by the top of the piston, the exposed cylinder walls, and the cylinder
head (with valves). This same space that you are trying to minimize
also gets invaded by the valves as they open (projecting into the
combustion chamber). If you move the piston up further to reduce the
volume, it moves closer to the valves that are trying to open as far as
possible for good breathing. So - bottom line - when optimizing the
performance, along with optimizing the shape of the chamber boundaries
for proper flow for performance and emissions, you eventually will hit a
point where the valves and pistons hit if they are not synchronized
(i.e., timing belt breaks). Normally (with good timing belt), that is
not a problem as the valves are closed or only partially open when the
piston is all the way up (at "TDC" - top dead center).

The manufacturer can do things like machine divots (reliefs) into the
tops of the pistons to allow higher compression while making room for
the valves to be open with piston at TDC, or add more valves per
cylinder to allow good breathing with lower valve opening height - but
such measures can add cost and/or degrade emissions.

So, basically, everything is a compromise. The manufacturers bet that
there is more gain to their bottom line by giving higher performance,
while minimizing their costs even if it increases maintenance costs or
risks of damage (which is probably a safe bet since 90+% of consumers
are ignorant of the risk anyway) - the old "What the customer doesn't
know won't hurt them" philosophy.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Sounds like what Ford did to their customers with Piston Slap. I won't be
purchasing another Ford Expedition again. I wonder how many customers Ford
lost because of this and if they even know.

Thanks again for another great explanation.

Ken