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[Silver Surfer]

Started my beloved '02 Aurora while parked in front of my house. Thought I
heard a loud thump but wasn't sure because the radio was a tad loud.
Noticed that power steering was absent, and the charge light was illuminated
brightly. Figured belt broke. Shut it down. No time to check now. Do it
tomorrow.

Wasn't the belt. Idler pulley bolt sheared off almost flush with the
alternator's mounting flange. Hard to reach. Not enough left to get hold
of with Vise Grips. Can't drill it. No way to get a drill down in there.
After looking over the arrangement under the hood my brilliant idea now is
to take off the thermostat housing and radiator hose in hopes it will allow
me to slide the alternator off the bolt's remains and get a much better shot
at it.

Decided maybe the thermostat should be replaced as preventive maintenance
after the housing is off. Headed off to the dealer feeling good about
"keeping my GM car all GM."

They could order the Tstat housing seal, but the new thermostat comes as a
housing/Tstat assembly. Right around $40. Choke! Gag!

Inquired about a new bolt for my idler pulley. They don't sell just the
bolt. Have to buy the pulley "assembly" also about $40. More choking and
gagging.

Decided to not replace the Tstat. Headed off to NAPA to get the seal.
Nope. They don't even sell the seal, just the assembly. About $33 my
discount price.

How about an idler pulley? Nope. They just sell the tensioner.

Got on line and queried Advance and AutoZone sites. Struck out there
although they did list a Prestone Tstat. GM Parts Direct looks promising.

Please forgive my ranting. I would like to know more about this
thermostat/housing assembly deal. Have never seen it up close and personal
yet as it's still on my machine. It truly can't be serviced by putting a
new Tstat in it?

How about that bolt for the idler? Can I just go to a place that sells
metric bolts and find a suitable replacement, or should I just spring for a
whole new pulley/bolt assembly?

[Silver Surfer]

Jonathan,

My tensioner assembly is just fine. It's the idler that bit the dust. I'm
not too keen on replacing the tensioner as a preventive measure because it
costs upwards of $80. Buying the whole new idler with bolt doesn't seem all
that inexpensive to me at $40. Maybe that's because I'm tighter than two
coats of paint. Thanks for your input.


"Jonathan" <Fire_Capt651@hotmail.com> wrote in message
news:zR8kf.3960$Hk1.148@newsread1.news.pas.earthlink.net...

[Jonathan]

Greetings,

I can't speak for the thermostat housing assembly, but I have an observation
concerning the pulley. Typically, there are two types of pulleys on single
serpentine belt systems - an idler pulley and a tensioner pulley.

An idler pulley is just bolted to whatever piece of metal happens to be
right where the pulley is needed, but a tensioner pulley is attached to a
spring-loaded arm that applies constant tension to your serpentine belt. If
you sheared off an idler pully then just buy the pulley (it comes with a new
bolt and it's pretty inexpensive), but if you sheared off the tensioner
pulley you will most likely have to purchase the entire tensioner assembly
(arm, pulley, bolt, tensioner spring, etc. as a one-piece unit). Most often
the bolt for this pulley is pressed into the end of the arm and is not
replaceable because turning this bolt is what allows you to pivot the arm
and release tension on the belt. The single bolt that passes through the
tensioner spring usually holds the assembly to it's mounting point and won't
affect the spring at all so you can remove it without having to worry about
unloading the spring.

If you're going to replace the tensioner you might as well replace the idler
pulley as well while your belt is off. The idler pulley is much easier to
replace because the bolt actually can be removed, and if you're into doing
preventative maintenance you might was well so that you have both pulleys
brand new. If not, hey it's only 3 years old and still has some miles left
on it.

Cheers - Jonathan

"Silver Surfer" <h.mcguffinspamouflage@comcast.net> wrote in message
news:ALmdndj_V6F3Zw3enZ2dnUVZ_sadnZ2d@comcast.com...

[Harry Face]

your T-Stat / housing reminds about the 5.3 V8 in the Silverado that
has the water pump & timing cover as one unit or something like that.
And i think the T Stat housing is also part of the puzzle piece.
Great engineering .

I thought about replacing my belt tensioner in 04 but I didn't.

Good Luck

Harryface
05 Park Avenue, 32,672
91 Bonneville LE 304,656

[Jonathan]

Greetings,

Well the next thing you have to think about is just why did the bolt shear
off? An idler pulley is an overly simple piece of machinery with nothing
more than the pulley, a bearing and a center bolt. The only thing that can
really go wrong is the bearing, and if the bearing fails then you will have
to replace the entire unit. If the bearing did have a failure (or was
starting to fail) and was starting to score the bolt causing it to shear off
then just replacing the bolt ain't going to do much for you except delay the
problem.

If you're dead set on not purchasing the entire assembly at $40.00 (I'm sure
you can do better from an online supplier), then you can take the pulley to
a place that does bearings and have a new set pressed in. They should also
be able to advise you on a new bolt (grade 8 I believe, not difficult to
find), but frankly by the time you get all of that done you will have spent
just as much in time and effort to repair the old pulley as you would to
simply replace it with a new one for a few bucks more. The prime reason why
certain parts come as complete assemblies is to reduce assembly and repair
times.

My advice is to take the part number from the pulley assembly and enter it
into parts websites from other GM products (since parts numbers are pretty
universal throughout the entire GM line). If your lucky, the same pulley
will also be used on another GM motor and you may be able to get it cheaper
from Chevy or Pontiac.

Cheers - Jonathan

"Silver Surfer" <h.mcguffinspamouflage@comcast.net> wrote in message
news:kLydnRfqgennsQzeRVn-jw@comcast.com...

[John Horner]

Silver Surfer wrote:

[451CTDS]

Bolts are bolts, my advice is to use the best bolts possible, use
Grade 8 in areas where maximum strength is needed. Stainless Steel
bolts are great if you keep cars " forever " I use them, with SS nuts
on exhaust systems, gas tank, thermostat housing, electrical [ ground ]
and any other troublesome area.

Would a Speed Shop sell a better Idler, or is a factory motor sport
version available ? Might be worth it to check parts dept on a slow
day, at more than one dealership, as attitude toward the unusual is met
with smiles, scowls, and little in between.