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Lm7 keeps eating up lifters. I've gone threw several cams and the same problem keeps occurring. I've replace the lifters, the cam, the trays, I've even put everything back to stock and I keep having the same problem. Any bit of information will help. Thanks in advance
03 silverado 5.3 lm7. Headers, 3200 stall converter, tune, prc Beehive springs, tsp harden push rods, stock heads. Melling high pressure high volume oil pump. I go about 500 miles before they start making a lot of noise and oil pressure go's crazy.
This has happened several times. Almost everytime I swapped a different cam in this happens. I always put fresh oil and filter everytime. I've replace the trays, put everything back to stock and it still happends. I don't reuse lifters. They are brand new.
You must check for proper pushrod length. The length of the pushrod determines the lifter preload, that's how you adjust preload.
I never new that. I guess that's a good thing to check before throwing it back together haha. How would you know the proper push rod length? I know you need a push rod length checker but how do you go about it? What's the correct preload?
I never new that. I guess that's a good thing to check before throwing it back together haha. How would you know the proper push rod length? I know you need a push rod length checker but how do you go about it? What's the correct preload?
With the lobe you're checking on the base circle adjust the pushrod checker till you get 0 lash, then add the preload you way to that, that is the pushrod length you want.
There are many great threads on how to do this, I would search for them and what ideal preload you need. Wether or not that's the issue I can't say for certain, but it's something you should do with any change to the valvetrain.
With the lobe you're checking on the base circle adjust the pushrod checker till you get 0 lash, then add the preload you way to that, that is the pushrod length you want.
There are many great threads on how to do this, I would search for them and what ideal preload you need. Wether or not that's the issue I can't say for certain, but it's something you should do with any change to the valvetrain.
I'll do some more research on this. Hopefully this will solve my problem. Much appreciated brotha
At this point, I would suspect you have contamination in the oiling system. Every time you fire it up, even with fresh oil in the bottom end, the contamination is still in the oiling system.
Every time a new set of parts fails it just cycles more contamination through the engine.
If it's always the same set of lifters there may be a physical obstruction within the block
At this point, I would suspect you have contamination in the oiling system. Every time you fire it up, even with fresh oil in the bottom end, the contamination is still in the oiling system.
Every time a new set of parts fails it just cycles more contamination through the engine.
If it's always the same set of lifters there may be a physical obstruction within the block
So how do I go about this? Do I pull through hole motor and clean her out? Maybe send it to the shop to get hot tanked?
Pulling it down and inspecting it would be a good start.
Hot tanking will only do so much. You need a set of brushes to clean out the oil galleries in the block.
If you find metal contamination issues, Throw the pick up tube and Oil pump in the trash and get new ones. I have tried several times to clean the pick ups and just when you think it's clean another spec of metal shakes loose. you can never get it all out of the screen and it's not worth trashing another motor.
Lm7 Lifter problem 
