Serious problem?

[reynoldsrobbie]

So I have been turbo since March and now I have come to the realize that I may have a serious problem. Back when I only had 8K on the engine I heard this loud ticking sound. I took it to the dealer and they had told me that it was piston slap. They replaced the whole bottom end under warranty.
Well the other day I reved it up pretty high and now Im recalling that ticking sound from the piston slap. Has anyone ever heard of this before? Now I have to decide if I go used, rebuild, build for power, or just throw in the towel and sell it to someone else to let them handle it. I still owe like 8K on it. I have been trying to sell it for 12K because of all the mods to it.

Anyone?????

 

[Turbo 331]

Are you sure it's piston slap? It could be an injector ticking

 

[reynoldsrobbie]

its pretty loud.

 

[Turbo 331]

Mine started ticking pretty loud since it's getting colder here. Let me ask u this.
After u been driving a while and come to a stop is it quite like normal and then all of a sudden you can here the ticking? That's wht mine is doing now. Injectors do tick pretty loud

 

[reynoldsrobbie]

its pretty loud. But I really seem to notice it when I get next to something and hear it echo. Its embarassing to go through the drive through and hearing it ticking so loud.

 

[Maxx Mazda]

My Arias pistons did that when it was real cold. Go one by one and unplug each injector. Tell me if the knocking gets less and on what cylinder.

Piston slap isn't bad, but it's annoying as s***.

 

[reynoldsrobbie]

I was wondering if it was really bad. I have been driving it everyday just waiting for it to let go. It is very annoying to say the least.

What causes the piston to slap like that?

 

[Maxx Mazda]

Basiucally, there's too much piston to cylinder wall clearance and the piston klinda "tilts" or "flops" back and forth. Since my pistons are forged aluminum, they expand at a different rate than the cylinders. Most forged internals make a bit of noise when cold. GM cars are espesially bad.

Google "GM Piston slap" and there's good articles on it.

Now, that beingsaid if your car suddenly starts doing it like mine did on my 3rd engine, you blew something. I broke a piece off my piston at 21psi cause of valve float. #4 went lean and broke, so it started slapping cause not only was there a chunk missing, but the piston was collapsed too. Basically, the piston gets so hot so fast that it expands WAY faster than the cylinder. It has nowhere to go but to expand back in on itself. I pulled it and measured it and it was 20 thou bigger one way. (Oval shaped.) Despite the noise, the car still ran and drove fine.

Long and the short of it is, diagnose it first with the injector trick. Then check your plugs and look for signs of ping. The FS motor doesn't ping very loud. You need a REAL sensitive ear to hear it. I've become accoustomed to what it sounds like in my engine so I knwo when to let off.

 

[reynoldsrobbie]

Thanks for the info. Ill check it out tomorrow.

 

[Turbo 331]

Any luck??