I'll Take "Pinpoint My Knock" for $250, Alex

bretamo

Member

May 13, 2005

122

1

16

Oct 7, 2007

#1

• Oct 7, 2007

• #1

My 92GT has a knock that has the rhythm and sound like a rocker arm hitting a valve cover, but I cannot pinpoint where it is coming from.

The knock disappears when I run the motor without the serpentine belt. So this tells me I have a problem with one of the accessories (AC Compressor, Power Steering Pump, Water Pump, or Alternator), correct?

I've turned each of the accessories by hand and do not find anything unusual.

So I am wondering if anyone has had an occurrence of a knock when tension is put on the crank pulley. Would a bearing inside the engine only produce a knock if tension were put on the pulley?

Does a Harmonic Balancer produce a knock before it goes bad?

Thanks in advance for your help.

 

91 HATCH

Banned

May 17, 2007

262

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illinois

Oct 7, 2007

#2

• Oct 7, 2007

• #2

it sounds like one of your accessories engine knock stays all the time and does not go away.

 

DLFD911

New Member

Nov 1, 2004

2

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Fort Wayne, Indiana

Oct 7, 2007

#3

• Oct 7, 2007

• #3

Have you tried putting your ear to a long screwdriver on the accessories while the knock is present? Might help pinpoint it. (don't try this on the balancer though )

 

347strokin

New Member

Oct 2, 2007

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Oct 7, 2007

#4

• Oct 7, 2007

• #4

Automotive stethoscopes are cheap too, and can definitely help in pinpointing sounds.

 

bretamo

Member

May 13, 2005

122

1

16

Oct 7, 2007

#5

• Oct 7, 2007

• #5

I put my ear to a heater hose to try to locate the knock, but I have not tried the screwdriver test.

Would a bearing inside the engine only produce a knock if tension were put on the pulley?

 

5.0TailPipeHump

Member

Dec 5, 2006

153

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Oct 7, 2007

#6

• Oct 7, 2007

• #6

347strokin said:

Automotive stethoscopes are cheap too, and can definitely help in pinpointing sounds.

Click to expand...

347stroker has the best idea by far by trying to locate an unusual sound , these autostethascopes are a good investment , i would try that route 1st .

 

F

Fox8950

Member

Jun 29, 2007

247

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18

Oct 7, 2007

#7

• Oct 7, 2007

• #7

If it were a bearing on the bottom end that was only knocking when you put tension on it the sound would be alot different than a rocker arm tick kind of sound or is that just the rhythm?

 

bretamo

Member

May 13, 2005

122

1

16

Oct 7, 2007

#8

• Oct 7, 2007

• #8

The best way for me to answer that question is to say that it is more a "knock" than a ticking sound. No knock when I run the engine without the belt for a minute. It is sometimes has varying degrees of knock, most often more prevalent when warmed up than cold.

I'm getting a stethoscope this week for this. I like getting new tools.

 

C

cjnecessary

Member

Mar 13, 2006

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richmond,in

Oct 7, 2007

#9

• Oct 7, 2007

• #9

I had an a/c pump do that to me years ago it sounded like the car had all the rods getting ready to come out the pan. I sure do miss that dodge.

 

bretamo

Member

May 13, 2005

122

1

16

Oct 8, 2007

#10

• Oct 8, 2007

• #10

Broken Aftermarket Underdrive Pulley

"What is a broken under drive pulley?"

That's what a paid mechanic said to me this morning. The MAC crank pulley is about a year old, and apparently cracked.

I can't believe I am paying a mechanic to replace it. A MARCH pulley is going on.

No more knock after I pay the bill tomorrow.

Thanks everyone for their help.

 

302RollinHard

New Member

Sep 26, 2005

0

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0

Columbus, OH

Oct 9, 2007

#11

• Oct 9, 2007

• #11

At the end of this thread there is only one thing to say...........
SUCK IT TREBEC!