My engine just started making a horrible knock. It sounds like it is coming from the driver's side head, so my initial thought was a stuck valve. But when I removed the valve cover none of them seem to be sticking. Any ideas what it is?

Thanks

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Black 88 GTA L98
!Airbox, !IAT, !MAF, !TB, !Plenum, SLP 1 3/4" headers, Dynomax Hi-Flo cat & cat-back, Corvette Servo
14.389 @ 95.2 mph, 2.001 60' {Before headers, new times coming soon)

 

It could be an exhuast leak. However, most of the time they make a clicking sound not a knock. You could have spun a bearing on the crank but you said you thought it was coming from your heads...so I would guess an exhuast leak.

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TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."

 

It may be a wiped out rocker ball... try listening to each valve assembly with a piece of heater hose as a stethoscope, and see if you can locate the source of the noise; then a little inspection should reveal the cause.

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"So many Mustangs, so little time..."

 

No, it is definately not an exhaust leak. There is a definate metal-on-metal sound.

I'll try listening to the rockers individually, thanks.

 

Well, I figured out what it is. Exactly what I was hoping it wasn't... I spun a bearing. I noticed that there was zero oil pressure, and after draining the oil and cutting open the filter I found metal everywhere.... I don't know if my oil pump failed or what. But now I get to call my parents tomorrow and tell them the wonderful news.

So, anyone know where I can get a good deal on a decent long block?

 

That is what I was afraid of. I have the same problem myself but for some reason mine is really living up to the chevy name LIKE A ROCK even though I don't have a truck. It has been doing it for well over a year and my mechanic still says it has a good 10k left in it....pretty wierd...usually a spun bearing kills the crank rather quickly. But I don't drive extremely hard. In fact I have been babying her for a while. Good Luck

------------------
TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."

 

Well, I pulled the engine last night. I spun the large end rod bearing on the #3 cylinder.

At least the upside is I can build myself and engine now.

 

I always wondered how people knew they spun a bearing before tearing the motor down- just look for metal in the oil filter?


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards

 

Not just metal, but if it's really shiny, silvery metal like a bearing is made out of, that's a good assumption of what it is.