Very angry knocking sound, need help!

fyfer · 02-12-2009, 05:07 PM

I have a 86 sammy and last week it started to klatter like nuts when i giver gas. Piston rod right? The thing is it only shows up at about 3000rpm when given gas, not when spooling down and when the ignition timming is out far enough so that it lacks any power, the noise goes away!

Any help would be much appreciated!

Pilsner Pig · 02-12-2009, 07:00 PM

Welcome aboard, a fellow BC 'zuki owner. We have had this subject come up on this site before and I have personally experienced it......I think it is the dreaded piston slap. I 'm not sure why it doesn't do it with the timing thing but it sounds like piston slap. If you get a chance look at the recent thread "engine knock" and I'm sure you can find more info with how other people have dealt with this.

Cheers

fyfer · 02-13-2009, 04:36 PM

Thanks, I'll check it out.

squid · 02-16-2009, 12:23 AM

two quick checks
1. pull dipstick and look closely at oil. if there are tiny gold flakes floating around that a sign a bearing has gone south.
2 if you hear the knock at idle, pull one plug wire at atime and if the knock goes away that is sign that the rod bearing is bad.

"piston slap" is when the skirt of the piston is worn and the piston rocks in the cylinder bore. it will usualy be loudest when the engine is cold . after the engine warns the piston will expand and knock will decrease. for some reason this is a common for the rear piston to develope the problem. I have seen engine run for a long time with piston slap knock. using 40w oil also seem to help.

Harleyindahouse · 02-16-2009, 05:14 AM

Quote:

Originally Posted by fyfer

I have a 86 sammy and last week it started to klatter like nuts when i giver gas. Piston rod right? The thing is it only shows up at about 3000rpm when given gas, not when spooling down and when the ignition timming is out far enough so that it lacks any power, the noise goes away!

Any help would be much appreciated!

$200.00 I have good 1.6 litre 8valve! PM me if your interested....

If your on the power when it occurs and only comes in at 3000 it does sound more like a bearing issue but not to say it can't be wrist pin either. You don't mention if you have any oil pressure warning but personally I would be more inclined to think wrist pin failure first. I had an old Pontiac that acted like that; one side broke so you couldn't hear the knock until you were at moderate power!

Harleyindahouse · 02-16-2009, 05:22 AM

You might try this first; warm it up completely at idle then increase rev slightly and dump 1/2 a litre or so of trans fluid down the throttle bore.

Somewhat rare but it could also be severe carbon knock!!! Worth a shot before finally giving in and putting the motor to rest.....

You can just saturate the throttle till it dies; leave it sit for an hour or so then start it and run until the fogging clears.

Pilsner Pig · 02-16-2009, 11:11 AM

Quote:

Originally Posted by Harleyindahouse

$200.00 I have good 1.6 litre 8valve! PM me if your interested....

Go for it. Call Kevin at KORE4X4 in Vancouver and get him to fab your tranny tabs and you are pure gold! I did this swap in my garage in 2 days and was amazed at how easy and awesome it is.

fyfer · 03-31-2009, 06:39 PM

Wow, $200? Very interested! Do you know how many kilometers are on it or if has had any work done? Would you be willing to part with the manifolds?

fyfer · 03-31-2009, 06:44 PM

Quote:

Originally Posted by Pilsner Pig

Go for it. Call Kevin at KORE4X4 in Vancouver and get him to fab your tranny tabs and you are pure gold! I did this swap in my garage in 2 days and was amazed at how easy and awesome it is.

Hey, Pilsner Pig, did you go for the fuel injection? Because I heard if you keep the carb you need a body lift for it to clear the hood. Also I have an '85 so that meens no compter, can I even do FI?