Engine Knock?

P

Prospect

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Jan 29, 2014

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Feb 19, 2014

#1

• Feb 19, 2014

• #1

I recently picked up a 90 GT, and when I bought it, it sounded great, ran good and I thought everything was fine. Since I bought it, I barely have driven it because of all of the snow we've been getting, but now it is making a knocking sound. Any idea what this could be? I'm waiting for a TFS top end kit to come in so I'm hoping this isn't bottom end.

View: http://www.youtube.com/watch?v=JoUpSaibYos

 

Grabbin' Asphalt

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Feb 19, 2014

#2

• Feb 19, 2014

• #2

Oh man, that sounds kinda deep, not like rocker chatter

 

Grabbin' Asphalt

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Feb 19, 2014

#3

• Feb 19, 2014

• #3

you can grab a hose and listen the old school way and try and hone in on it, but any bearing cam, rod, crank will require you know what.

 

P

Prospect

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Feb 19, 2014

#4

• Feb 19, 2014

• #4

You think it's a bearing?

 

84Ttop

They make new pistons every day, so why worry?

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Feb 19, 2014

#5

• Feb 19, 2014

• #5

Doesn't sounds good. Obviously hard to pin point in a video but leads me tonlean towards classic rod knock...

 

madspeed

Colonel Mustard

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Feb 19, 2014

#6

• Feb 19, 2014

• #6

could be rocker hitting the baffles inside those non efi valve covers

 

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Grabbin' Asphalt

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Feb 19, 2014

#7

• Feb 19, 2014

• #7

madspeed said:

could be rocker hitting the baffles inside those non efi valve covers

Click to expand...

cannot hurt to look at that top shelf clearance, probably would be marks on the underside of the covers, ...hope thats it!!

 

madspeed

Colonel Mustard

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Feb 19, 2014

#8

• Feb 19, 2014

• #8

they look like standard chrome stamped steel valve cover for a non efi sbf. They likely have baffles inside them that do not provide the necessary clearance for roller rockers. Easy to check

 

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P

Prospect

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Jan 29, 2014

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Feb 20, 2014

#9

• Feb 20, 2014

• #9

When I first bought the car it didn't make any sort of sound like this. If it were the covers, wouldn't it always sound like this?

 

P

Prospect

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Feb 20, 2014

#10

• Feb 20, 2014

• #10

Also, the guy I bought it from did tell me that he had an exhaust leak that he had fixed. Could it be a loose header?

 

A5literMan

At least it is lumpy...

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Feb 20, 2014

#11

• Feb 20, 2014

• #11

Pull the valve covers and check and see if the rockers are hitting the baffles like mad speed recommended. You can also check for an exhaust leak(doesn't really sound like it though). If they both check out fine I fear it's rebuild time

 

P

Prospect

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Feb 20, 2014

#12

• Feb 20, 2014

• #12

I was pulling the whole motor out anyway, and this may be a blessing in disguise

 

P

Prospect

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Feb 20, 2014

#13

• Feb 20, 2014

• #13

http://www.summitracing.com/parts/fem-mhp173-300/overview/make/ford

Good for a rebuild?

 

Fordfreak93

Mustang Master

Mar 12, 2009

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Feb 20, 2014

#14

• Feb 20, 2014

• #14

I've seen the harmonic balancer come apart and make a noise similar to that. The balancer has a rubber sleeve inside that wears out or pushes itself out and it causes a god awful noise when it does. Sounded like the engine was coming apart! Sometimes the rubber will stick out or you can see it wobble. Might be worth a look...

 

P

Prospect

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Feb 20, 2014

#15

• Feb 20, 2014

• #15

I'll take another video of the balancer. My dad actually thinks it's either the balancer or a bearing down low as well.

 

Fordfreak93

Mustang Master

Mar 12, 2009

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Feb 20, 2014

#16

• Feb 20, 2014

• #16

Winter can be hell on rubber parts, definitely check it out. The rubber wears out and causes the inner and outer rings to "knock" together. This is not a mustang balancer, but you get the idea

 

P

Prospect

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Feb 20, 2014

#17

• Feb 20, 2014

• #17

Yeah, especially this winter. This winter has been brutal on this car. Cracked the windshield, sagged the door preventing it from shutting, and now the motor. This all happened within 2 weeks from buying it.

 

Grabbin' Asphalt

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Feb 20, 2014

#18

• Feb 20, 2014

• #18

Fordfreak93 said:

I've seen the harmonic balancer come apart and make a noise similar to that. The balancer has a rubber sleeve inside that wears out or pushes itself out and it causes a god awful noise when it does. Sounded like the engine was coming apart! Sometimes the rubber will stick out or you can see it wobble. Might be worth a look...

Click to expand...

Yup very possible

 

8

89llx

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Feb 22, 2014

#19

• Feb 22, 2014

• #19

do you see copper metal flake in the oil on the dip stick,, look at it in the sun

 

mikestang63

SN Certified Technician

Aug 27, 2012

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Feb 23, 2014

#20

• Feb 23, 2014

• #20

cut the oil filter in half. Pray you don't see gold, copper, or silver. Since you are taking the motor out anyway, once you pull the pan and a bearing cap let us know.