What could it be?

[Yellow 13]

So, my #1 cylinders had a loud knocking coming from it. I know its #1 because I can hear it through the engine and when I pulled out the #1 sparkplug it became very noticeable.

The piston had no play sitting in the cylinder and there are no scars on the cylinder wall. I pulled the piston out to check the pins and bearings.

According to the Toyota tech I talked to you check wristpins by putting them halfway into the rod and wiggling them, no wiggle means ther fine. Did that and no wiggle, perfect fit.

I then checked the crank, no scars, still perfectly smooth.

Then too rod bearings (these are being reused from before the teardown).
They seem a little to arched, like they have to be bent slightly outward to fit onto the crank. Just slightly though. I dont know if thats how theyre supposed to be or what.

 

[phoenix6]

u checked your valves?

Im pulling apart my head bc I had the same problem, didnt go as far as you to make sure it wasnt rod knock but pull off the head and check your valves.

 

[IJ.]

13: Do the rod bearings snap into the rod and not fall out if you shake it?

 

[Yellow 13]

Phoenix: The head was rebuilt about 500 miles ago, and I ran it on my other engine before. The noise is also definitely bottom end related (Slow knocking).

IJ: It wont even stick with oil for suction. So I take it thats the sign of a bad bearing?

 

[IJ.]

13: It's detonation damage!

aka: Hammered bearings

Time for a new set and make sure you check the ringlands as they will have suffered!

 

[phoenix6]

ouch... well I take it its already apart so your a little ahead. Let us know how it goes.

 

[Yellow 13]

Probally detonation from before the rebuild, running 87 octane (prolly worse at the rundown place i get gas...85'ish), out of timing at high RPMS. I reused the bearings from before so I suppose theyre no good. But the engine didnt knock before and I put them all back in the same place.

The new setup was run on 92 octane in timing and only for about 10 mins on new pistons/rings. I pulled #1 and didnt see any damage.

Ill go get some plastigauge tommorow and order a set of new bearings from the stealership.



Could the quality of a deglazing job be the cause. I deglazed them with a stone type tool. My friends done deglazing on his cars a few times before and said it was a good job. but It was my first attempt.

 

[IJ.]

Any marks on the backside of the bearings?

 

[Yellow 13]

Theres some black that looks like scoring youd see on a flywheel, on the inside theres a line of wear down the center of each bearing.

Tried to get some pics but the camera died.

Edit heres the best my shitty cam could do since it doesnt have macro:

 

[IJ.]

Are the Tabs still there?

 

[Yellow 13]

Tabs are still there, you can barely make one out on the left in the pic. ^

 

[IJ.]

Does your camera have a Macro setting ? (Usually a little flower icon)

 

[Yellow 13]

I wish. This cameras from the dawn of digicams. I have take picture and turn on/off.

 

[IJ.]

A bit hard to make out!

Either way if they've lost their crush they're stuffed and should never have gone back in

 

[Yellow 13]

No idea what crush or stuffed means. But I take it that means get new ones and replace the whole set.

 

[IJ.]

"Crush" is the snap fit when you put the bearing into the rod or cap, the bearing is slightly larger in diameter then the rod hole and as you tighten the cap the bearing "crushes" into place.

The ends of the bearing are spread out a bit and when you hammer a bearing they pull in like yours. (this is a bad thing)

"Stuffed" aka fucked knackered screwed rooted aka not good