Pushrod wear
Haven't seen that wear on an LS motor. But was common on the old SBC engines due to over extended oil changes. Also same issue on a 3L Ford Aerostar that the customer supplied Schaeffer's semi synthetic oil.
Also seeing a lot of engine wear & sludge issues from lack of oil changes. There are a lot of people that believe the OEM oil change light is a good indicator of when to change oil.
The OEM extended oil change intervals is all about profits and NOTHING to do with engine life. That is because most new vehicles come with a 4 year no charge "scheduled maintenance" So by extending oil changes to 7500+ miles (max 1 oil change per year on my sister's 2014 Malibou), that is saving GM a lot of money on oil changes. And now all the auto manufactures are extending the oil change intervals just to stay competitive. And they claim that their saving the environment (even though used oil is recycled)
GM even has some TSB's about engine noise due to over extended oil changes on the 3.6L engine. So the timing chains & guides are replaced and the PCM is reflashed to shorten the oil change intervals. Good thing the customer is not made aware of the fact the their engine is failing because of not changing the oil enough.
And in a performance engine, using the so called "new car formula" oil is a very bad idea.
Russ Kemp
Also seeing a lot of engine wear & sludge issues from lack of oil changes. There are a lot of people that believe the OEM oil change light is a good indicator of when to change oil.
The OEM extended oil change intervals is all about profits and NOTHING to do with engine life. That is because most new vehicles come with a 4 year no charge "scheduled maintenance" So by extending oil changes to 7500+ miles (max 1 oil change per year on my sister's 2014 Malibou), that is saving GM a lot of money on oil changes. And now all the auto manufactures are extending the oil change intervals just to stay competitive. And they claim that their saving the environment (even though used oil is recycled)
GM even has some TSB's about engine noise due to over extended oil changes on the 3.6L engine. So the timing chains & guides are replaced and the PCM is reflashed to shorten the oil change intervals. Good thing the customer is not made aware of the fact the their engine is failing because of not changing the oil enough.
And in a performance engine, using the so called "new car formula" oil is a very bad idea.
Russ Kemp
I had the same issue with an all original ls1, with 83k on the clock. The car was dealer maintained ( 7500 mile oil changes). I replaced all the rockers and pushrods, engine was quiet for a while, but the piston slap was just too much for me so I swapped out the LS1 for an LQ4. If I had to guess, I would say it was lack of oiling.
Russ Kemp
Last edited by Russ K; Jun 22, 2014 at 09:56 PM.
Likewise. None to very little sludge but brown.
Should I just replace the effected rockers and a new set of pushrods and run it?
I was going to put some 11/32 rods in anyways.
From what I'm reading it looks like motors with this condition still have good looking bearings. Can anyone else confirm that their bearings looked good despite the worn pushrods?
I'm also thinking that if I went that route, I'd like to confirm adequate oil flow from the lifters through the pushrods. Maybe run the engine with the valve covers off to see? Or can I hook up some kind of pump to the oil gallery and check it while its on the stand?
Should I just replace the effected rockers and a new set of pushrods and run it?
I was going to put some 11/32 rods in anyways.
From what I'm reading it looks like motors with this condition still have good looking bearings. Can anyone else confirm that their bearings looked good despite the worn pushrods?
I'm also thinking that if I went that route, I'd like to confirm adequate oil flow from the lifters through the pushrods. Maybe run the engine with the valve covers off to see? Or can I hook up some kind of pump to the oil gallery and check it while its on the stand?
I had four or five that looked like that in a JY 5.3, it also killed the rocker on that lobe too.
I wish I had a pic, but they looked just like that. Gummy lifter restricted oil to the top. The motor I had also had wiped out cam bearings, but you can have bad lifters without dead bearings.
One thing to consider is that without oil flow out of that pushrod the valve springs don't get the same cooling. Might wanna pull a couple "good" and "bad" ones and have em tested. It's cheap peace of mind.
I wish I had a pic, but they looked just like that. Gummy lifter restricted oil to the top. The motor I had also had wiped out cam bearings, but you can have bad lifters without dead bearings.
One thing to consider is that without oil flow out of that pushrod the valve springs don't get the same cooling. Might wanna pull a couple "good" and "bad" ones and have em tested. It's cheap peace of mind.
Well, I checked them again and indeed have no signs of contact with the hole in the head. In all I have 6 that are worn like this. No blockages in any of them and the lifter end looks good too. I can only assume that the lifters are clogged a bit. I was intending on throwing a used cam in it and a set of 11/32 pushrods and running it. But now it looks like I'll have to tear into it to at least do the lifters. If I have to go that far into it, I might as well have a look at the rod bearings and possibly the mains I suppose. Anyone have any suggestions?
I was just doing a top end rebuild because of the milage on the motor. I would for sure replace the lifters with the push rods looking like that. I am thinking the motor had around 285, 000 miles on it with oil changes os Mobil1 Extended every 10,000 miles. My wife drives the car now because i bought a Corvette. The Z28 now has 321,000 miles on it with the original crank and pistons. Ys really can't beat them Chevy motors. Wow yes and old thread I was surprised to see it. 
