using a bit of logic to locate a problems source.

[Grumpy]

one of my neighbors owns a 1995 corvette,very similar to this car

he mentioned that the car has developed the nasty habit of having a high frequency squealing type noise when he starts it up.
He figured his alternator bearings must be shot, so he order and installed a new $300... 200 amp alternator and yes he was impressed with how the whole car ran better,
as the old alternator was obviously marginal,
but the high frequency squealing type noise when he starts it up remained?
I suggested he pull trouble codes ,
approaching the problem logically with an isolate and test mentality would be the fastest way to cure the issue.
Id suggest he pull the belt and spin the accessories by hand to feel for bad bearings and listen for roughness, binding or squeaks, etc.
but he stated that he checked recently, but the car had showed no trouble codes.
ok he said, too himself, it must be the LT1 water pump ,
and knowing Id recently replaced my 1996 corvettes water pump, he asked me to help.
http://garage.grumpysperformance.com/index.php?threads/i-need-a-new-lt1-water-pump.10723/#post-47422
as he had already ordered the water pump and UPS had delivered it that afternoon.
I asked him how many miles were on the old water pump, and he said he was unsure if the water pump on the car was original as the car had 30K on the odometer,
when he bought it and close to 90K miles now...
I figured it must be original and no harm in swapping it out,
(it took both of us working at a lea-surly pace together about two hours)
but I told him that he ought to remove the serpentine belt and spin each individual accessory,
while the belt was off, by hand to feel for the cause of the squealing, after replacing the water pump and before installing the serpentine belt,
we did check and both the idler pulley and power steering pump,
showed signs of potentially causing the squeal issue.
and yes after we installed the water pump the squeal still remained.
I have no idea why its so difficult to research the source of that noise issue,
by removing the serpentine belt,
and then individually spinning and feeling, each accessory while the belt was off, by hand too feel for slack , movement in the bearings,or wear or roughness
,the cause of the squealing,but he had not thought about doing that.
I also suggested running the engine briefly without the belt to listen for vacuum leaks and loose vacuum hose connections
(remember the LT1 water pumps driven by the cam not the belt)

BTW it generally helps if you post the city and state your in,
as theres at least some chance a local member,
may want to stop by and help you diagnose,
and maybe help rectify the issue if your LOCAL

http://www.rockauto.com/en/catalog/...l+v8+ohv,1041376,belt+drive,idler+pulley,6956

http://www.rockauto.com/en/catalog/...ohv,1041376,steering,power+steering+pump,7380

http://garage.grumpysperformance.co...lean-surface-crud-off-paint.13765/#post-70656

http://garage.grumpysperformance.co...g-serpentine-hoses-and-belts.3060/#post-19273

http://garage.grumpysperformance.co...oming-on-if-air-conditioner-on-cooling.12232/

http://garage.grumpysperformance.co...-top-end-intermittent-knock.11751/#post-55460

http://garage.grumpysperformance.co...ght-a-1995-corvette-so-what-size-engine.9363/

http://garage.grumpysperformance.com/index.php?threads/c4-c5-corvette-trouble-codes.2697/#post-18904

http://garage.grumpysperformance.com/index.php?threads/lt1-cooling-info.2538/#post-6583

 

[Indycars]

You have to face reality Grumpy, you are smarter than than average bear !!!

.

 

[T-Test]

Belt itself could be the culprit.

 

[Grumpy]

yes that might be true, thank you for pointing out that possibility
YES I SHOULD HAVE MENTIONED THAT!
I at times over look pointing out the obvious
approaching the problem logically with an isolate and test mentality would be the fastest way to cure the issue.
Id suggest he pull the belt and spin the accessories by hand to feel for bad bearings and listen for roughness, binding or squeaks, etc. in the search for the cause of that squealing on start-up,once youve eliminated the obvious accessory bearings, and replaced any accessory or idler you found defective or worn, Id certainly check for power steering pump leaks ,,loose or damaged crank vibration damper/balancer, loose or mis-aligned pulleys, and check the air conditioning compressor and alternator along with the water pump and idler pulley bearing,a worn serpentine belt is easily checked with a good spray down with belt traction spray,
and / or replacing the belt ( especially if it shows any sign of wear or cracks)and check for loose vacuum hoses or belt mis-alignment while your at the check and isolate process

CROSSFIRE

LT1/LT4

LT5

L98

http://www.supercheapauto.com.au/Product/CRC-Belt-Grip-400g/1444

http://garage.grumpysperformance.com/index.php?threads/wheel-hub-replaced.14766/

you really need to purchase a multi meter and a SHOP MANUAL and look thru the schematics
without testing theres almost no way to locate the source of your problem,, testing will tell you

http://www.helminc.com/helm

http://www.harborfreight.com/5-in-1-dig ... 98674.html
heres a cheap yet effective multi meter

http://garage.grumpysperformance.co...sing-a-crazy-electrical-glitch.986/#post-1738

http://garage.grumpysperformance.co...your-c4-corvette-runs-badly.15212/#post-87228

most guys have little real experience at isolate and test procedures and many can,t use test equipment or even fully understand what to look for.
DON,T PAY FOR IT ...DO IT YOURSELF!!!
IT WILL COST LESS EVEN AFTER PAYING FOR THE TOOLS, than paying for it AT MOST GARAGES.
A compression test,ALONE, IS NOT A LEAK DOWN TEST, a LEAK DOWN TEST WILL GIVE YOU THE COMPRESSION TEST INFO, ALONG WITH OTHER INFO

you'll find that you'll gain basic skills, own new tools and PAY LESS MONEY

http://en.wikipedia.org/wiki/Leak-down_tester

http://www.carcraft.com/techarticles/11 ... index.html

BEFORE YOU GET INVOLVED WITH TESTING , YOUR ENGINE,READ THRU THESE THREADS, AND LINKS AS THEY WILL HELP ISOLATE THE PROBLEM, and THEY HAVE A GOOD DEAL OF USEFUL INFO
you really need

http://www.testequipmentdepot.com/e...1100200223789&utm_content=All Extech Products
INFRARED TEMP GUN

a timing light,

http://www.harborfreight.com/3-1-2-half ... 95670.html
multi meter,

vacuum gauge,

fuel pressure gauge

http://www.harborfreight.com/cylinder-l ... 94190.html

HARBOR FREIGHT, UNDER $40

http://buy1.snapon.com/products/diagnos ... pv309a.asp

SNAP ON $330

http://www.summitracing.com/parts/SUM-900010/

http://www.summitracing.com/parts/OTC-5609/

SUMMIT $80-$100
compression test /leak down tester

dial indicator with stand

and a degree wheel

damper tool

and a shop manual
and more related reference material
certainly won,t hurt

http://garage.grumpysperformance.com/index.php?threads/verifying-your-real-advance-curve.4683/

http://garage.grumpysperformance.com/index.php?threads/bare-minimum-tools.11026/#post-48779

http://garage.grumpysperformance.co...-rather-than-jumping-in-with-both-feet.14918/

1996 radiator cooling fan relay how to test

Hello all, I have a 1996 Vette LT-4, radiator cooling fans are not coming on. I have checked the fuse panel on the passenger side of the dash, I have also checked the maxi fuses in front on the battery. am now desirous of checking the cooling fan relays, how to do this? thanks in advance for any/all guidance


There are three relays involved.
You can identify the relays by the color of the wires at each relay socket.

Turn the ignition On.
At the relay socket.
Ground the Dark Green wire and both fans should run at low speed.
Ground both the Dark green wire and the Dark Blue wire and both fans should run at hi speed.

every mechanic needs an ANALOG multi meter for testing capacitors with a micro farad scale, AND a DIGITAL MULTI METER

http://forum.grumpysperformance.com/viewtopic.php?f=36&t=63&p=3403&hilit=vats#p3403

use of a shop manual and multi meter can be very helpful
http://www.harborfreight.com/5-in-1-digital-multimeter-98674.html
READ THIS THREAD

http://forum.grumpysperformance.com/viewtopic.php?f=32&t=3954

READ THESE LINKS AND SUB LINKS
http://garage.grumpysperformance.com/index.php?threads/cooling-off-that-c4-corvette.3954/

http://garage.grumpysperformance.co...-air-conditioner-on-cooling.12232/#post-59597

http://garage.grumpysperformance.co...sion-and-oil-cooler-increases-durability.176/

http://garage.grumpysperformance.co...ans-cooler-on-a-c4-corvette.10514/#post-44478

http://garage.grumpysperformance.com/index.php?threads/i-need-a-new-lt1-water-pump.10723/

Id bet most guys will look at the cost of the traction spray,
then price a new belt and quite logically say to themselves,
it makes more sense to swap to a new belt than buy spray,
and find it may not work, and then buy a new belt if it doesn,t work
https://www.ecklerscorvette.com/engine-and-related/belts.html
http://www.rockauto.com/en/catalog/chevrolet,1996,corvette,5.7l+v8,1041398,belt+drive,belt,8900

https://www.the12volt.com/relays/relaydiagrams.asp (read)

85 and 87a -> Ground

86 -> Power

30 -> Output

-30 = constant [positive (+)] power (usually wired directly to car battery)
-85 = coil ground (wired to the negative (-) battery terminal or any grounded metal panel in the car)
-86 = coil power (wired to the control source. could be a switch, or it could be the car's IGN or ACC circuit.)
-87 = switched [positive (+)] power output. (when the relay coil is powered, lead/pin 87 is connected to lead/pin 30)
-87a = [on 5 lead/pin relays only] this lead/pin is connected to lead/pin 30 when the coil is NOT powered.

any thoughts gentlemen?

be aware the electrical grounds 104-105,106,107 must be checked and firmly connected to the engine

a factory shop manual and a v.o.m. meter come in handy for testing!
http://www.chevythunder.com/Flow chart index.htm

the factory installed, tuned port high ohms injectors, should read between about 11 ohms and 13 ohms resistance

http://garage.grumpysperformance.co...ouble-shooting-rebuilding-hei-ignitions.2798/
potentially related threads, these links hold a great deal of info

http://garage.grumpysperformance.com/index.php?threads/c4-c5-corvette-trouble-codes.2697/#post-91077

http://garage.grumpysperformance.com/index.php?threads/gm-tpi-stalling-diagnosis.15194/#post-86992

http://garage.grumpysperformance.com/index.php?threads/maf-burn-off-relay-info.661/#post-908

http://garage.grumpysperformance.com/index.php?threads/testing-1985-89-m-a-f-sensor.1475/#post-3325

http://garage.grumpysperformance.co...oven-facts-if-your-in-doubt.13051/#post-84695

http://garage.grumpysperformance.co...-won-t-start-intermittently.14212/#post-72158

http://garage.grumpysperformance.co...urrent-flow-grounds-and-more.3504/#post-54624

http://garage.grumpysperformance.co...start-right-back-up-and-run.10739/#post-46893

http://garage.grumpysperformance.co...-idles-and-sometimes-stalls.10688/#post-46308

http://garage.grumpysperformance.co...m-with-how-your-c4-corvette-runs-badly.15212/

http://garage.grumpysperformance.com/index.php?threads/1989-corvette-shows-a-trouble-code-33.15594/

 

[Loves302Chevy]

On v-belts, every time I used that spray, the belt snapped a short time later.

Believe it or not, WD-40 works great for checking belt squeal. Just spray it on the belt, squeal
disappears, then a few minutes later the squeal returns. You have your proof. Replace the belt.

 

[Grumpy]

thanks, Ill mention that too him