HELP! !new engine rebuilt knoking!!!

[2001cobra2001]

Just got my 01 cobra engine rebuilt by a local shop and it has a knoking sound, it sound as if its coming from heads first time they put it together its was knoking pritty bad and they blamed it on the used 98 cobra cams i bought, then i bought some new crower stage 1 cams and engine is still having same issues at this point i dont no what to do, they told me that because they forged my engine it sound like that but i still think there something wrong with the engine. Need some help guys...thanks

 

[usmc_cwo7002]

Anyway you can post a video?

 

[2001cobra2001]

Bump

 

[2001cobra2001]

Yeah i can try.

 

[3B99SVT]

I've heard forged pistons can have some piston slap until the motor gets up to heat but as soon as everything has reached temperature the motor should quiet down. Does your knocking go away after the motor has reached temp?

 

[2001cobra2001]

Knoking doesn't go way at all.

 

[itSSlow98]

Mine sounds horrible when I start it when its cold out but is silent once it warms up. We need a video to help. The psiton slap on cold starts is the nature of some forged pistons.

 

[2001cobra2001]

Ill try posting one tomorrow.

 

[slonech]

Have you changed the oil and looked for any shavings?

 

[98 N/A 4V]

Try and isolate it to see if its coming from one of the heads. Could be that they bled down the adjusters and one of them is not filling back up with oil. I did that to my motor and one of them took a few start ups to get filled. But it went away.

-Mark

 

[2001cobra2001]

No shavings.

 

[Black*Death]

That suxs. Has that shop built a lot of modular engines?

 

[2001cobra2001]

Dont no but just found out that there mainly a pushrod engine shop.

 

[2001cobra2001]

Bump

 

[Weather Man]

Have to find a shop that knows modular engines. Post a vid to get help online.

 

[01yellercobra]

Sounds like the shop screwed something up. Did they even remove the valve covers before telling you that you needed $1200 cams? If you don't have an aftermarket oil pressure gauge get one and hook it up. Make sure you have oil pressure.

 

[ElscottHavoc]

If its smoking, I'd ask if they used a torque plate. Some shops that don't mess with mod motors much will skip the torque plate and then the cylinders will be out of round when you torque the heads down. The torque plate simulates that during bore and honing. I think those plates are quite expensive, especially if only used on rare occasions, but my car smoked like a mofo when rebuilt without. Then had to have it bored larger to fix with the plate.

As far as knocking, that isn't right. You might get minor piston slap and some cold start knocking that goes away once the car gets up to operating temp but persistent knocking isn't right. Forged internals often get pinned as sounding differently if you have a keen ear for that, but my forged Scat Rods, Diamond Pistons, and forged crank sound just like prior my rebuild.

Posted via Topify on Android

 

[racecougar]

What oil pressure are you seeing at cold idle? Have you opened up the oil filter and inspected the filter media? You might not find any shavings/material in the oil, while the filter media will be packed with "glitter". A good, clear video would help us hear what you're hearing.

 

[Weather Man]

What did you find out?