So in continuing my 2 for 2 streak of buying crappy cars with hidden problems, my car has a rod knock. When I bought it there was a very loud timing chain rattle. It was an easy fix- pull the valve cover and notice that the upper timing guide has broken off and is bouncing around in the timing cover . Of course I pulled the other one and unstuck the tensioners in the interest of doing things right. Unfortunately when I started it back up there was a much quieter rattling noise, one which goes away when you pull the #2 spark plug or fuel injector wire.

Is there anything else it could be? All I can think of is #1 rod knock, #2 bad exhaust leak on cyl #2 only, #3 spark plug wire arcing, #4 bad wrist pin or something else weird like that (?). I already eliminated the plug wire thing by swapping them around, and I'm 95% confident it's not an exhaust leak. It really sounds like it's coming from the block, though I couldn't isolate it anywhere with the screwdriver-ear trick.

If anybody has any suggestions let me know- I'd like to check everything before I buy another engine and tear this one down for a rebuild.

 

if its a ka then its rodknock.

 

bad motor..

 

piston slap, carbon on the pistons that hits the head on every stroke (seen it), sounds just like it. there's a lot of things, you just need to listen to the source area then you'll figure out what is causing it.

 

if you've every heard a rob knock, then you would know if it is a rod knock or not... its a very distictive sound , especially with these engines...
my buddy's 240 has a bit of a knocking type sound, on the number 2 piston... its the valve seal on what seems to be the front exhaust valve...
you've really got to narrow down where the noise is coming from...
if its down low on the block, then its probably rod knock, it it is in the head, then its got to do with the valves... if it seems to be both, one then the other and back and forth,then it is probably a bad wrist pin...
good luck

 

ask blake aka kung fu grip. he has rodknock and is in denial due to lack of automobile knowledge.

 

I've heard rod knock on an SR before, bad rod knock (spun bearing). I've also heard it on a KA in a video. This isn't nearly as loud or "rattle-y" but it does get faster with rpm and does go away when you take away fuel or spark. You mostly hear it at idle and in the 2k-3k RPM range but I can't tell if it goes away at other times or is just drowned out by usual KA truck noises. I did find a post on ka-t that said mild rod knock can start at certain RPM then progress slowly to total failure.

I'll try again to isolate it. I had a screwdriver on the oil pan under cylinder 2, on the valve cover above it, and on the intake and exhaust manifolds/ cyl head at 2 and couldn't hear it through the screwdriver.

 

What does your oil psi look like? And quick check... take your dipstick and drop a few drops of oil on the windshield, while in the sun, and see if you can see tiny metal flakes in the oil... if you can, chances are it's a lower end bearing taking a crap... You can save if it the bearing hasnt spun yet.

 

correction.... you may be able to save it....