411 swap did not go well

[blindawg]

I have hit the Rev limiter many times in my 2000 S10. Everything still holds together... for now. lol.
I would check the flexplate. Also, probably not the cause of it, but check the Dust guard on the Drive shaft... thing. please excuse my lack of termenolgy, for the name of the part excapes me at the moment. It's the support on the shorter piece of the two piece drive shaft. Mine came loose and cause a high pitch noice becasue of the vibrations. Like I said, probably unlikely.

Branden.

[FeetDry]

I have hit the Rev limiter many times in my 2000 S10. Everything still holds together... for now. lol.
I would check the flexplate. Also, probably not the cause of it, but check the Dust guard on the Drive shaft... thing. please excuse my lack of termenolgy, for the name of the part excapes me at the moment. It's the support on the shorter piece of the two piece drive shaft. Mine came loose and cause a high pitch noice becasue of the vibrations. Like I said, probably unlikely.

Branden.

The sound is coming from the back pass side of the engine, or the bell housing. I beleive the dust guard you are refering to is the driveshaft carrier bearing.

[FeetDry]

What is your engine's firing order...?

1 - 6 - 5 - 4 - 3 - 2 These use a reprogrammed distrib cap.

[FeetDry]

Do you have a log of while it is running? Does your knock sensor have a bolt that runs through it, or does it thread into the engine?

It threads into the block behind the distrib cap. B1402 has been set to resonant.

I have a small log from a ~10 min warmup cycle. It is the LS1 sample (default). It has the GM.KR & WB AFR data. Retard due to knock stays at zero. The AFR's are just under 12 to 14. It is mostly in the 13's.

[FeetDry]

I'm just trying to think of other things that could be wrong. Did you pull the spark plugs out yet? Are they all the same? What do the fuel trims look like on each bank?

I have not pulled the plugs yet. I'm trying to avoid that. #6 is a real bear to get to. I don't have the fuel tirm data.

[FeetDry]

Crankshaft speed is twice the camshaft speed.
Does this sound like crank or cam speed to you? (It idles at 600RPM)
The shreiking is not too clear in the audio. It sounds like just another bang.

http://www.youtube.com/watch?v=gn2HPJZABk8
http://www.youtube.com/watch?v=1v-cA5juv9s

The only Knock PID I can find in LS1B is the KnockRetard. Am I missing some?
KR is showing no retard. The knock sensor is just a few inches away from where it is loudest. (And there is no knock retard?)

[Taz]

Listened to both clips several times ... difficult to make an absolute determination ... it sounds like it's a mechanical issue - obviously not positive on that based on a video clip. If it is mechanical - high probability it's a rod bearing. In my experience, rod bearing issues tend to be a "common" problem with the 4.3 L V6.

Hopefully it turns out to be something else ......


Regards,
Taz

[schwoch1]

After listening, I am almost 100% positive that you have a rod knock going on there!!! COuld be wrong, have had several flexplates cracked over the years that sound like rods bearings, but my gut feeling says that it has a rod bearing out!!! How did it run before the swap? Just swapping the PCM wouldnt cause any issues like this!!! Keep us posted!!!

Mike

[FeetDry]

How did it run before the swap? Mike

It ran fine. There was no indication that it was going to let go.

The noise is coming from the back of the engine, it is loudest in the bell housing. But I'm thinking it is banging slower than the crankshaft. So I'll have a look at the rest of the valve train next. If that is not it, then I have to yank the engine to do anything else. I'd like to avoid yanking the engine.
Maybe I'm just trying to make myself believe that it is not a rod bearing.

Thanks

[Taz]

Obviously, do your best to rule out all other options. If you do end up removing the engine it's fairly straight forward. The bolts that secure the transmission to the engine can be a challenge near the body seam. I usually use a 3 foot extension on a universal equipped socket. Once the engine is out, I will generally employ a large hammer to flatten the body seam / reshape the trans tunnel for more easy installation.

The oil pan is a little tight to the cross member. For lack of a better descriptor - the oil pan is a Gen III cast aluminum style pan - and if removed / replaced it needs to be properly aligned with the rear face of the engine block (just like a Gen III).

Hopefully it doesn't come to that ...


Regards,
Taz