l76 dod lifter rattle
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Teching In
Joined: Jul 2008
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From: Australia, Adelaide
l76 dod lifter rattle I have fitted crow 4918 valve springs to and l76 dod engine in readiness for a larger cam install at a later date. When i start my engine it ran fine then once it warmed up at about 1000rpm it sounds like the lifters collapse and there was a rattle from the motor.
Has anyone com across this problem before and if so does this mean that valves have hit pistons or would it be just lifter rattle.
the valve train etc is all original except for 600lift springs.
I am thinking to refit my original valve springs until i am ready to fit cam and change the lifters.
Any input would be great
Thanks
Has anyone com across this problem before and if so does this mean that valves have hit pistons or would it be just lifter rattle.
the valve train etc is all original except for 600lift springs.
I am thinking to refit my original valve springs until i am ready to fit cam and change the lifters.
Any input would be great
Thanks
From what I've heard, the DOD lifters don't like excessive spring pressure. I'd reinstall the original springs until it's "cam" time. Hopefully, you will also be replacing the 8 DOD lifters with regular ones?
Thread Starter
Teching In
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From: Australia, Adelaide
Yeah will change all the lifters when its cam change time, but for now i need to get the car registered and a stock cam is a must for my inspection.
thanks i am going to return the stock springs tomorrow and see what happens
thanks i am going to return the stock springs tomorrow and see what happens
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I would belive that the lifters are damaged. Not that I have seen alot failure, but they are picky, and prone to ticking.
When you do the cam swap. Are you going to remove the DOD plate in the valley, and tune the ecm? If you don't. It will set codes, and try apply oil to them.
When you do the cam swap. Are you going to remove the DOD plate in the valley, and tune the ecm? If you don't. It will set codes, and try apply oil to them.
Thread Starter
Teching In
Joined: Jul 2008
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From: Australia, Adelaide
I have already got a rough tune and had to delete all dod software as this caused 4 cylinders to cut out injector pulse at all times other than startup.
I have already changed the valley plate to try and solve that problem of running on 4, so all good there just waiting for head gaskets and lifters to change them out.
Thanks
I have already changed the valley plate to try and solve that problem of running on 4, so all good there just waiting for head gaskets and lifters to change them out.
Thanks
I have seen quite a few DOD lifter/cam lobe failures just at my uncle's small town auto shop. I also spoke to a dealership tech that said they have been replacing them on a regular basis. The lobes on the cam are failing like the bad batch of improperly heat treated cam cores from a few years back. The lifter is wearing a groove into the cam lobe until it gets to the point that the lifter body contacts the cam on both sides of the roller.
If it were me I would make sure the cam is in good condition before dropping a new set of lifters on top of it. It would suck to have to change them twice.
If it were me I would make sure the cam is in good condition before dropping a new set of lifters on top of it. It would suck to have to change them twice.
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From: Your GF's pants
DoD lifters over all have horrendous problems. The lockout pins are where your rattling comes from, however the big springs most likely damaged the lockouts and retention springs on the DoD's.... They are just one example of GM's good ideas that failed. Just like the Cadillac's 8/6/4 way back in the day.
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Staging Lane
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DoD lifters over all have horrendous problems. The lockout pins are where your rattling comes from, however the big springs most likely damaged the lockouts and retention springs on the DoD's.... They are just one example of GM's good ideas that failed. Just like the Cadillac's 8/6/4 way back in the day.
