2013 Escalade ESV DOD full delete becoming rebuild

[West 1]

The bearings look near perfect. No chance they are your noise issue. If you had metal in the oil the wear marks would all be centered on the oil supply holes which are near center feed on the crankshaft. You are doing all the checks correctly so far.

If your crank was ground .010 under did you verify the bearings installed are marked the same? .010. All bearing companies I know of will list the part number and the oversize on the part.

My 6.2L oil pressure drops from 60 psi on cold start to a hot idle pressure of 25 psi at 148,000 miles. I don’t like the drop but all comments I have read on these aluminum blocks that is normal. Hot oil pressure above 1,000 RPM is 50+.

Your minor scratches in the bearings are just in the Tin plate. The tin plate is only there to keep the bearings looking the same/pretty, it does offer minor break in lubrication and keeps the bearings from aging while sitting new in the box. From manufacture to actual install can be years for these parts, tin plate works to protect them. It is only a few millionths of an inch thick so they show even minor scratches like yours are showing. You can scratch tin plate with your finger nail as it is very soft.

The rods get oil after the mains so I do not suspect main bearing damage?

The fact it was quiet and became noisy is the most concerning.
No metal in the oil is very good, yes after rebuild of any engine the first oil change will find machining particles in the oil filter but that should be zero after this first oil change.

I think my next move would be to install a bore scope in each cylinder with the piston at the bottom of its stroke and check the piston head and bore for any odd marks, damage or spare parts in the cylinder. If something is in there the piston head will be beat and show many impact marks.

On your lifers/push rods/ Rocker Arms pre load is pre set on the LS. If your piston is at TDC on the compression stroke both Rocker Arms will be a little loose. In any position other than TDC one or both rocker arms will be tight or under valve lift tension?

Engine ran smoothly other than the knock?

 

[skpyle]

The bearings look near perfect. No chance they are your noise issue. If you had metal in the oil the wear marks would all be centered on the oil supply holes which are near center feed on the crankshaft. You are doing all the checks correctly so far.

I agree. Thanks for the confidence!

If your crank was ground .010 under did you verify the bearings installed are marked the same? .010. All bearing companies I know of will list the part number and the oversize on the part.

Crank was ground 0.010" under on both the rods and mains. Matching 0.010" under King bearings were installed. I checked clearances with plastigauge during assembly. Approximately 0.0025" on the mains and approximately 0.0015" on rods.

My 6.2L oil pressure drops from 60 psi on cold start to a hot idle pressure of 25 psi at 148,000 miles. I don’t like the drop but all comments I have read on these aluminum blocks that is normal. Hot oil pressure above 1,000 RPM is 50+.

Before the overhaul, oil pressure was great! Cold start was 52PSI, hot idle was above 30PSI.
I don't recall what oil pressure was while driving, but I wasn't ever concerned.
I did find something in my notes for overhaul that now stands out: connecting rod set side clearances were between 0.017" and 0.019". Spec is 0.00433-0.020". Mine are right near the top end of spec. This 'could' be bleeding off oil pressure more than necessary. Though, if the rod bearing clearances were proper and tight, that shouldn't be an issue...

Your minor scratches in the bearings are just in the Tin plate. The tin plate is only there to keep the bearings looking the same/pretty, it does offer minor break in lubrication and keeps the bearings from aging while sitting new in the box. From manufacture to actual install can be years for these parts, tin plate works to protect them. It is only a few millionths of an inch thick so they show even minor scratches like yours are showing. You can scratch tin plate with your finger nail as it is very soft.

Very good to know! I did not realize that. I have not built very many engines, so I don't profess to be an expert, or even good at it. I am just detail oriented and know how to read a service manual.

The rods get oil after the mains so I do not suspect main bearing damage?

Agreed. Also, the main cap bolts are TTY, and I wouldn't be able to test run the engine again after inspection. Based upon what I saw in the rod bearings, and the thrust clearance, I guessed that the mains were OK.

The fact it was quiet and became noisy is the most concerning.

Yes! Something changed. And not for the better.

No metal in the oil is very good, yes after rebuild of any engine the first oil change will find machining particles in the oil filter but that should be zero after this first oil change.

I can see that, but honestly still think break in wear is happening past 100 miles.

I think my next move would be to install a bore scope in each cylinder with the piston at the bottom of its stroke and check the piston head and bore for any odd marks, damage or spare parts in the cylinder. If something is in there the piston head will be beat and show many impact marks.

I have ordered a bore scope inspection camera, should be here Tuesday. I will be off work Thursday and Friday. I will check the combustion chambers then.

On your lifers/push rods/ Rocker Arms pre load is pre set on the LS. If your piston is at TDC on the compression stroke both Rocker Arms will be a little loose. In any position other than TDC one or both rocker arms will be tight or under valve lift tension?

Understood. I read up on it when I built the engine, but since everything was going back together 'stock', I didn't check preload. See my next post...

Engine ran smoothly other than the knock?

Engine ran like a top! I drove it gingerly, with repeated variations in RPM. I kept the tach below 4000rpm for break in. Same reason I kept the AC off. Coolant temp was steady, throttle response was excellent. It started right up each time I stopped. No strange noises. It wasn't until partway in that I started hearing the tapping and noticed oil pressure was lower than I thought it should be.


Thanks!

 

[skpyle]

This weekend, I have done the following:

-inspected both catalytic converter pipe flanges to the exhaust manifolds. All nuts were tight, flange gaps were tight and even. I saw no soot or evidence of exhaust leakage.
-inspected top and bottom of both exhaust manifolds. There were no gaps between the manifold faces and the cylinder heads, both gaskets were intact. All bolts were tight. I saw no soot or evidence of exhaust leakage.
-removed both valve covers and inspected the valve train. Saw no obvious damage. No rocker arms were floppy or excessively loose.

-turned the crankshaft until #1 cylinder exhaust valve started to open. Verified #1 intake rocker arm was loose side to side. I removed the rocker arm and pushrod. Both looked good, no damage. Ball ends hadn't even started to wear in on the pushrod. NOTE: pushrods were Michigan Motorsports 5/16" OD x 0.080" wall x 7.400" length. Rocker arms all had BTR TK002NB LS rocker arm trunion upgrade.
I reinstalled the pushrod and rocker arm, then hand tightened the bolt down to zero lash for the rocker arm and pushrod. I then counted turns to seat the bolt. It took approximately 1 7/8 turns to seat the bolt.
From what I have found on the internet, rough rule of thumb for stock LS lifters is 3/4 - 1 1/4 turns to tighten. This sets 0.050" - 0.080" preload.

Soooo...I have too much preload on the lifters. However, this is A problem, but I don't think it is THE problem. No preload makes lifters tap. Too much preload makes lifters pump up sooner and possibly hold valves off seats.
Engine ran fine, no missing, no check engine light.

I bought an adjustable pushrod back when I was assembling the engine. I should have used it then. I used it now. Pushrods are available in 0.025" increments. So I started experimenting.
7.350" pushrod took approximately 1 3/8 turns to seat the bolt from zero lash.
7.325" pushrod took approximately 7/8 turn to seat the bolt from zero lash.

At this point, I was not sure if I wanted a little less or a little more preload. Meaning 7.350" or 7.325" long pushrods.
NOTE: I am running bulk Delphi LS7 lifters from Michigan Motorsports. The recommended preload is 0.050" - 0.100" for these lifters.

https://www.michiganmotorsports.com...tyzLGxl9s9I1-c_rjsHyEuYr3mDeG8192lGZUX_UxwJho


Back to the internet.

I found this helpful chart showing effects of number of turns of the bolt on lifter preload. In a nutshell, every 1/4 turn is approximately 0.020" of preload.


https://www.corvetteforum.com/forum...out-a-dial-indicator-or-checking-pushrod.html



Then, I found a machinist explaining how to use an adjustable pushrod to find how long a pushrod is needed for zero lash. Then you add your desired preload to that length.

Ah-HA! I can do that.

I went back out to my 6.2L and started experimenting with pushrod length to find zero lash. Eventually, I figured out that 7.255" gave me zero lash on #1 cylinder exhaust valve. The bolt seated just a hair past zero lash.
This tells me I want a pushrod with length of 7.305" (for 0.050" preload) to 7.355" (for 0.100" preload).

A 7.300" pushrod would give 0.045" preload (too little). A 7.325" pushrod would give 0.070" preload (goldilocks, just right).

OK, so I want 7.325" long pushrods for this to be right. Granted, this does not solve my tapping/knocking issue, but it DOES have to be addressed sooner or later.

Also, if 7.255" gives zero lash, then 7.400" gives 0.145" preload. Way too much!
Meaning with the GM L9H camshaft, bulk Delphi LS7 lifters, stock rocker arms with upgraded trunions, and 7.400" pushrods, lifter preload was 0.145".

I checked the following valves for the above info:
#1 cylinder intake
#1 cylinder exhaust
#2 cylinder intake
#2 cylinder exhaust
#3 cylinder intake
#3 cylinder exhaust
#4 cylinder intake
#4 cylinder exhaust

All were the same. 7.255" pushrod had zero lash and the bolt seated a hair past that.
Also, I was able to depress the lifter plunger some with my thumb on the pushrod for each valve.

I am going to check cylinders 5-8 tomorrow. One, to verify they are the same as the above info. Two, to see if any lifters feel 'funny'.


Also, random thing I saw on the internet: supposedly, aftermarket trunion upgrade kits result in needing shorter pushrods. Not sure why. I would think the trunion dimensions are the same for stock and aftermarket.

 

[SpareParts]

With the rods and mains appearing good and with dropping oil pressure maybe something is going on with the cam?

 

[skpyle]

#1 cylinder intake and exhaust rocker arms.

Passenger’s side valve train.

MM 7.400” pushrod, adjustable pushrod set to 7.325”, and the calipers I used for all this.

 

[skpyle]

With the rods and mains appearing good and with dropping oil pressure maybe something is going on with the cam?

That is definitely a concern! Cam bearings were replaced with new coated Durabond bearings. Camshaft installed tight and smooth into them.

However...if I don't find anything in the lifters, or if I do, next step is removing the engine again and hanging it on my engine stand. Deeper surgery required.


Thanks!

 

[West 1]

Couple notes. Your lifers don’t need specific pre load to work. There is a piston inside the lifter that is adjusted by oil pressure and does not move unless your valve train is adjusted. Since the LS style has no adjustment the lifters will adjust to your build as soon as you start the engine. Less than 60 seconds after start up the lifters are adjusted and done.

The lifer has a range, maybe .120 of an inch of travel to adjust to your valve train. The lifter will operate normally at any point in that range. So long as it is not bottomed out, say .120 down or left loose so it is adjusts fully up they are fine. As already stated if you adjust them fully down the lifter becomes a solid lifter with no adjustment and if your push rod is long the valve can be hung open when it is supposed bo be closed but in that case you lose compression in that cylinder and have a miss. You did not mention any miss?

If the lifter is adjusted so it is fully up, there is no more adjustment so it can leave a valve loose. Minor loose can add some valve train rattle. Really loose can let push rods get out of the rocker arm and get bent and start banging.
This would also be associated with a miss as one valve would not longer be working.

With the valve covers off you only need to verify all 16 rocker arms are moving the same amount as the engine rotates, you can do this by running the starter as you watch each. Feel them to make sure one is not loose compared to all the others.

It is possible for some machining debrie to get into a lifter and make it stop adjusting, it does happen sometimes after a rebuild, in that case the piston inside the lifter can’t move to adjust and you are stuck with one bad lifter that would need to be changed out. They do not just fix themselfs but the signs and symtoms would be a tapping loose lifer or a stuck open valve causing a miss.

I saw the coated new cam bearings in your photo. They should work if properly installed so all the oil holes are lined up with the oil gallery feed holes.

Mains at .0025 in an aluminum block are certainly within spec but on the high end and will bleed off some oil pressure. I would prefer them to be .00175 to .002 but .0025 will work fine you just know it will have lower idle oil pressure when hot.

 

[West 1]

Did you by chance run the engine while listening to sounds in the Timing Chain cover? I was wondering if there is any chance the tensioner broke leaving you with chain slap noises?

Just kicking the can around trying to help find your issue.

 

[j91z28d1]

just went back and read thru the whole thread. man you were very thorough with this rebuild.

I'm sorry to hear it's got some issue. I have no idea what it is, but I'm very curious as to what you find.

that machine shop bill had to hurt. I can only guess that included the new pistons and all the bearings and stuff. not just the bore hone and crank sizing. if so man I have a ls3 I have been putting off building. I haven't talked to a shop for pricing yet. but I might just go crate motor if prices have gone up that much. ugh.

 

[rdezs]

Did you by chance run the engine while listening to sounds in the Timing Chain cover? I was wondering if there is any chance the tensioner broke leaving you with chain slap noises?

Just kicking the can around trying to help find your issue.

I'm on board with looking under the timing cover as well.

If the tensioner came apart, timing chain flopping around, variable valve timing fluctuating trying to keep up, noise....