hi im new to this site but i just got a 89 yota it has 309,000 miles on it but runs great and strong but it has a knocking sound. i cant figure out if its a rod knock or maybe its the chain. i want to figure it out before i have to replace the engine. any help would be great. Ill try to post a vid of the noise so you guys can hear it.

 

Try pulling each plug wire with the engine running and see if the knock stops, if it does, that is the bad hole. But yes a video or more info is needed for a closer diagnosis.

 

with that many miles i would say its a rod knock, time to rebuild!

 

heres a video of it. sorry its not the greatest but it was taken with my phone.

<iframe width="480" height="390" src="https://www.youtube.com/embed/gX9U54HiAZk" frameborder="0" allowfullscreen></iframe>

 

http://youtu.be/gX9U54HiAZk

 

the second one should work i wasnt too familiar with posting a vid sorry

 

it sounds like a diesel motor, yeah i would say rod knock and u might be able to save it if u just replace the rod bearings, but not sure how bad it has wore the journals. or rebuild the motor and get another 300,000 miles.

 

ya tomorrow im gonna check it out to see if its something else.

 

Well figured out its not a rod knock so that's good but the knock is only there on idle and when revved up it goes away. I'm thinkin it needs a valve job

 

stuck valve or rocker assy?

 

that isn't a rod knock as you already pretty much know. That sounds like a timing chain hitting the timing cover. Rev'd up sounds about right for that too since oil pressure is higher at higher rpms which means the chain tensioner is "tighter". It might be the tensioner itself but would still require a timing chain job.

edit, here's the vid to make it easier for others.

http://www.youtube.com/watch?v=gX9U54HiAZk

 

That was one of my thoughts but wasn't sure but a new timing chain isn't too bad to replace ill have to pull the cover off and take a look

 

Well I still have a knock I replaced the timing chain and tensioner. Did a cable job and found the valves to be really tight. But I used a stethoscope and pinpointed it to the back left of the valve cover on the intake side. The only thing I can think of is the rocker arm in loose. When you listen with the stethoscope you can hear the metallic pinging.