Well I've made it home for the summer and it's time to start tearing this thing apart. I will begin tomorrow, but yesterday I took it to the dyno. Laid down 503 / 1215. I was very pleased with the numbers, but the knocking is getting worse to it's time to take it apart.

 

I don't recall on oring on my CR block, but may have missed that part.

As far as the exhaust valves the EGTs have a way of keeping them clean, even if there is an oil leak.

Why not pull the crank if everything else is coming out?

I don't recall on oring on my CR block, but may have missed that part.

As far as the exhaust valves the EGTs have a way of keeping them clean, even if there is an oil leak.

Why not pull the crank if everything else is coming out?

I guess 1600* will keep things burned off!

 

Why take it out though? I'm not having it balanced or turned, so I see no point in removing it. 

Are you not going to tank the block? I fiugred you would tank it to clean out all the hidden oil and coolant passages, since it is out.

i didnt see an oring on the back of the block for the cam bore when i rebuilt, it has a freeze plug sealing it up

 

I have seen them both ways, not sure why they did it that way, about 6 months ago I just helped a friend with an 03 auto who had a shop do some tranny work for him and they replaced the rear adapter housing due to a crack and we found they forgot to put the o-ring in when we got it apart, it had a pretty fair oil leak if you could imagine.

Are you not going to tank the block? I fiugred you would tank it to clean out all the hidden oil and coolant passages, since it is out.

No. I've only got so much money and so much time. I will clean everything out the best I can. There's nothing wrong with the block though 

Have you ha a chance to pull the pistons and look at them? I've seen a couple of cracked pistons that looked normal in the hole but then when pulled they showed there damage. 

the oil on the valves looks like the valve guides and seals are leaking pretty good.

Usually labor is the expense in rods and mains for bearing replacement. I would definitely replace since you've already done the labor. Sorry if it's been asked and answered but did you check wrist pins and piston skirts. The sound I heard in the vid sounds like piston slap caused by a stiff wrist pin.

The pistons haven't come out yet. I'm waiting to get the motor up on an engine stand before I go any further. I should be picking up the stand Tuesday, so hopefully I'll get the adapter made Tuesday night and get it on the stand Wednesday.

 

I'm still waiting on a quote for the head.... that's probably where the big money will go, then it'll just nickle and dime me to death.

 

I did speak with a guy who runs his own trucking business and has been rebuilding Cummins engines for 20+ years. He said from the sound he hears it's an injection knock....

I told him everything I've done and how all the tests have come back good so he's thinking it's ECM related. He says that's why I can't track it down to one cylinder.... it's something going haywire in the ECM causing a weird injection. Does that make sense to anyone else?

so he's thinking it's ECM related.

 

I hate to rain on your project.... But what if you tear it all apart and find nothing? What if it's the ECM all along?

It really doesnt sounds like an injection issue to me.... but it is hard to diagnose over the interweb of sound conversion.

I hate to rain on your project.... But what if you tear it all apart and find nothing? What if it's the ECM all along?

Then I spent a lot of money to find out my internals are healthy!   O well though. The engine needed resealed, and I wanted to clean up the engine bay anyway.

 

The knock was so inconsistent - that's why he thinks ecm and not hard parts. He said hard parts would have a constant knock.

Hard parts are not always cosistant, especially if they rotate. I have seen hard parts that need to have 2 bad surfaces line up for noise and they dont always do that.

Wrist pins are also possible for intermittant knocks based on irregular wear and rotation, they basically change the compression ratio.

I know the feeling of rebuilding a motor that didn't need it... but oh well I now I have a fresh/better motor.

it really sounds like wrist pin slap to me. i used headphones and nice speakers. but i guess will see. as of yet still havent found the root cause.

why pull the engine and not inspect everything, pull the pistons and inspect the rings and bearing, dont halfway it and end up putting it back in just to have the issue still there then pull it out and find its something you could have fixed the first time. I say this as i almost made this mistake last year when rebuilding mine. I though i could get away with pulling #6 in the frame and honing the hell out of it, but im glad i did a full rebuild as i wouldnt have seen the damage done to all bearings and the fact that honing wouldnt have fixed the scoring.

 

do it fully right the first time!

Edited May 16, 20159 yr by CUMMINSDIESELPWR

Don't worry the pistons are coming out! Just not for a bit. I've done a few things today. I started cleaning sealing surfaces and got the ECM flashed back to stock. Tomorrow I plan to pull all of the wiring back and give the bay a good wash job. Then I can start re-doing the wiring harness and painting the bay. 

nice!

Pictures are required... Oh so what was missing on the loom? When you call you had that No Bus issue.

The damper is shot. The rubber is starting to work its way out, so I'll need a new one.

 

My 2 cents get a Fluid Damper I love mine, was worth the price.

Edited May 16, 20159 yr by klcammie

Pictures are required... Oh so what was missing on the loom? When you call you had that No Bus issue.

I'm doing my best! Sometimes I forget to stop and snap a couple pictures....

I found a ground loose on the passenger side that connects to the PCM. The little grey plug was plugged in, but my brother must have unbolted the body ground. I've got it flashed back to stock now, so no worries. Thanks for the help!

 

The damper is shot. The rubber is starting to work its way out, so I'll need a new one.

 

My 2 cents get a Fluid Damper I love mine, was worth the price.

Thank you! That was my plan but it's good to have some reassurance.

If you need a hand TFaoro just hollar. I'm off on the weekends and have just about any tool needed.