bkuhr

Ball stuck in lifter

other end of pushrod galled

ball stuck in rocker

First some history,
2006 GMC 1500 vin T 5.3, 250,000 miles
Valves tapping noise started, comes and goes with no detectable cause or reason. Running semi-synth 5w-30, oil pressure typically 30-40psi. Decided likely a collapsing lifter unable to hold oil pressure. Although I could pull the heads and replace the lifters, due to high mileage, I decided it would be better for a complete rebuild. With that in mind, I decided to get a second engine built up, then swap them out on a long weekend.
Purchased from junkyard, 2002 gmc 1500 vin T 5.3, verified vin and rear end damage, engine should be fine.
Tore the 2002 engine down, machine-shop worked on block/heads and spec'd crank and cam, replaced cam bearings, and ordered master rebuild kit with bearings, new lifters, new oil pump and timing kit. All to 2006 specs.

On reassembly, I finished bottom end, filling oil pickup and priming oil pump while upside down. Then wife had a medical emergency that put rebuild on back burner for about 2 months-she recovered just fine.
The rockers and pushrods had been soaking in solvent for 2 months, and cleaning up good, but I did neglect to ensure the push rod bore was clear, and some of the push rods could have had their oil passages plugged/blocked, but it is unlikely.While on engine stand, tried to turn engine by hand until I got oil out the rocker arms (covers off), but I could not get any oil to come up, and figured I just can’t turn it fast enough.

Finally, on a 4-day weekend, I started and completed the engine swap. Found a few year specific issues that forced me to swap the 2002 parts off the rebuild motor and put the original 2006 parts on.
-2002 throttle body had dual throttle cables, vs electronic throttle body on the 2006.
-2002 fuel rail had pressure and return fuel lines, and vacuum regulator from intake manifold, where 2006 had a single fuel pressure line (I guess this is pressure regulated at the pump), and the vacuum port on the intake used on the 2002 is closed on the 2006 manifold.

Had difficulty getting the engine to start, crank and crank, but would not hit a lick. Verified spark and fuel pressure. Some ether, and it started, and would restart when warm, but next cold cycle required ether again. Indicated zero oil pressure, and thinking back to inability to bring oil up while on stand, there must be something wrong with oil pickup or pump, such as bad pick O-ring. Dreading taking either the front or bottom covers off while in truck to verify O-ring, I decided I needed to verify no oil pressure. Due to a tall (2002) oil pressure sensor, recessed under the firewall, I was unable to pull the sensor, so I pulled an oil gallery plug right behind the power steering pump. I did not have fitting to fit for a pressure gauge, but held my finger over it during crank, and oil sprayed out past my finger, but did not appear to be 40ish psi. I figured I do have pressure, although it seems low, but I am indicating nothing, it must be a sensor problem. So off comes the intake manifold to be able to reach the oil pressure sensor, and replaced it with the original 2006 sensor, which is short compared to the 2002. Crank without start, and indicated about 20psi- so it was all just a bad sensor, and no need to get to the oil pick up or pump. -Yah

Putting everything back together, engine finally starts normally, without need for ether, sounds great-very quiet, and idle oil pressure 45-50, and high rpm oil pressure about 60.

Now the new problem- daily driver for 200 miles since rebuild, on the way home and I think I hear valve tapping. Slowed down and sped up, and verified it was me, and not other traffic noise. 10-mile ride home, and getting progressively louder, and feels like I am losing power. On arrival home, popped hood and confirmed tapping from drivers’ side near the front, sounds like #1.Waiting for the weekend to look at it, I finally am able to pull the valve cover.
I can jiggle #2 intake rocker, but not excessive, but when I got to #2 exhaust, it was loose as a goose. Unbolt this rocker, and it was still torqued down, so rocker had not backed off. Lift the rocker and found pushrod destroyed, the pushrod ball is stuck in the rocker. The other end of the push rod is galled, and I am fearing I also have damage down at the lifters.So, off comes intake and left head, pulling the plastic lifter cap, none of the lifters came out with the cap, but I did verify orientation of the flat sides while they were still in the bore, and the lifters had not rotated. Extracting with magnet, and all lifters appear to be undamaged except some slight score marks lower end of lifter body, rollers roll fine and are undamaged, and looking thru lifter bore, cam surface also appears undamaged.

So, this all leads to the unanswered question. It appears the pushrod/rocker arm damage is due to lack of oil, but why and how, and what do I need to do about it??? I am at a loss. I do not know the brand of the new lifters, but is it possible for the internals of a lifter to be defective, and not allow oil thru the pushrod?
Is it possible my combination of 2002 motor rebuilt with 2006 specs and parts is causing a problem? It there a difference between 2002 and 2006 rocker arms, as I now have some damaged rocker arms that need replaced.
Why did I have such a hard time starting at first, requiring ether?
Any and all replies or suggestions appreciated, as I can not explain my failure, and do not what to but it back together without the root cause addressed.
Thanks all

Brian

poltergeist 02

iTrader: (65)

bkuhr

That's my general thought also, but trying to understand how brand new lifters could be defective.
Also is there some way to test lifters, to verify they fill with oil, and push it up the pushrods?
I would hate to just throw some new parts in there without some confidence that the problem has been solved, and end up with the same problem again

bkuhr

stock rebuild, lifters, and reset of parts ordered as stock, and lifter appear same size as the old lifters
and I cant get the pics to come up, not sure why- finally got pics up, they were to big,size wise, I guess

s30.hybrid

iTrader: (3)

s30.hybrid

iTrader: (3)

bkuhr

I put this engine together, and no, I did not check lifter preload. This is a great idea. I also had no idea about the LS1 and LS7 lifters. I am going to do some measurements from the old lifters removed, and the new ones installed, but right now I am thinking I need to get another, known quality set of lifters- any suggestions?
My machinist ordered the lifters for me, and I did not save the box they came in, so I can not verify what brand or model they were- next week I'll see if my machinist has a record of what was ordered.
Thank you for the thought- this could explain the issue, and is forcing me to ensure it is considered on reassembly.

vettenuts

iTrader: (4)

The LS7 lifters are stock replacements for the LS1 lifters without a pushrod change.

I would put it back together replacing the bad parts and then remove plugs, unplug coil packs and spin the motor with the starter with the valve cover off. You should see oil come up to the rocker. I would also use a good assembly lube like Redline on both ends of the pushrods and top of the valve stem to prevent a dry start. They do make a pushrod cleaning brush for the oil hole for a few bucks.

bkuhr

I measured my lifters with thought toward the above mentions difference between LS1 and LS7.The original 2002 lifters measured 2.597” overall length, and the new lifters measured the same. The old lifters did have pn JH3 in the side, but the new ones have no numbers at all.

I then stuck the veneer depth gage down the lifter cup, from the lifter top. The 2002 measured .418”, and the new lifter measured .434”, but I realized that my depth gauge was going thru the oil hole and resting on the metering plate beneath the cup on both lifters. So, I took one of my damaged push rods, and cut off a short, apx 1”, section, where the ball end would sit properly in the lifter cup, and I could measure OAL of the lifter with short pushrod section. The 2002 lifter measured 3.495” and the new lifter was 3.543”, a difference of the new lifters are .047” taller.

Although 2 of the pushrods were galled on the lifter side, I took a galled pushrod and spun it in the cup of both the rocker arms and the lifters. I can feel it interface with the rocker arms that have gall damage in the cup, and it feels smooth on undamaged rocker arms. With this process, I have the rocker arm with the ball stuck in it, and 2 more rocker arms, #5ex and #7ex that also feel galled. Doing the same process, I have only 1 lifter that I can feel a bit of interface with the lifter cup, #7in. I still have not pulled the right valve cover or head, so when I do, I plan to see what the lifter preload was set at before disassembly. Then I need to verify any damage in pushrods, rocker arms, lifters, same as left side.
When ordering parts
1.Although I could order single lifters, I can not confirm the manu or pn, and I do not think I should take a change on mismatched parts- should I order complete new lifter set?
2. Same question applies to my damaged rocker arms, is there some way to confirm rocker arm pn/manufacturer, to ensure order the same?
3. Is there a suggestion for make/model of lifters and rocker arms for this stock rebuild?
Brian

tech@WS6store

iTrader: (2)

The simple answer is, the stock ball end pushrods have weak points. High mileage makes this apparent. Ive seen no less than 10 this year push the ball end into the tube.
Hunting for another explanation is going to leave you without an answer and a bunch of wasted time a gray hair.
Use a swedged end 1 piece and youll be fine.

poltergeist 02

iTrader: (65)

bkuhr

what about the rockers I can feel damage in the pushrod cups, they should be replaced also, correct?

G Atsma

Common sense here; if ANYTHING shows damage, replace it AND the part it mates with. And as tech@WS6store said, use quality pushrods with swedged ends. A full set of pushrods would be a good idea here.

wannafbody

iTrader: (2)

I'd replace them to be safe. Might want to do a trunnion upgrade since they are off the heads.

poltergeist 02

iTrader: (65)

bkuhr

Just 3 on left side, haven't opened right side yet

G Atsma

Here is what I would do to play it safe if there are more than 6 or 7 ruined rockers total:
ALL new rockers with bushing-type trunnion upgrade. (Straub or CHE)
A set of swedged-end pushrods, correctly measured for
Edit: I'm liking the new springs idea that others mention. This with all the above would give you a very secure head setup.

wannafbody

iTrader: (2)

Does the old rocker rotate freely? Maybe a bearing got bound up in the rocker.

tech@WS6store

iTrader: (2)

Id get some new springs also whether they be ls6 or whatever. Unless you have new ones already.
We have brand new rocker sets for $215 with hd trunion, hd pushrods, best price on lifters and gaskets also.

Let us know we can fix you up!!

Mike Morris

iTrader: (55)

I think new springs would be a wise thing to do as well.