Loud noise

[Rock-It Man]

Originally Posted by NOT A 45

I'm a tech at a Chevy dealer....even the new ones are collapsing. The LT1 & LT4 engines are having the same problems but they also have a bent push rod and a wiped camshaft. I have yet to see a collapsed non AFM lifter so if it were me, I'd do a AFM delete since you'll have the heads off anyway.

Can you comment on the new V6 AFM mechanism. I imagine that, with overhead cams, it's quite different, but is it any more reliable?

[morepowerjoe]

But he lives in California. A tune will get him a failed inspection.

[NOT A 45]

Not too familiar with the V6 as I haven't had one apart yet. But I understand the design. The difference in this engine is that the AFM works with the rocker arms and not the lifters or lash adjusters. The rockers on cylinders 2&5 are actually hinged. They are controlled by a oil feed solenoid commanded by the ecm. When oil is fed to the rocker it unlatches and valves don't open. No oil feed causes them to latch and become ridged like a normal arm. Seems to me if this system fails it will fail in 6 cylinder mode with no drivability issue other than a check engine light.

[Rock-It Man]

Originally Posted by NOT A 45

Not too familiar with the V6 as I haven't had one apart yet. But I understand the design. The difference in this engine is that the AFM works with the rocker arms and not the lifters or lash adjusters. The rockers on cylinders 2&5 are actually hinged. They are controlled by a oil feed solenoid commanded by the ecm. When oil is fed to the rocker it unlatches and valves don't open. No oil feed causes them to latch and become ridged like a normal arm. Seems to me if this system fails it will fail in 6 cylinder mode with no drivability issue other than a check engine light.

Thanks for the insight!

I have a 2010 that's going to get replaced by a Gen6 when the availability improves, and I'm torn between a V6 and V8.

The V8 AFM experience with my 2010 2SS was a bummer, even though the lifters were replaced at no cost to me. And the Gen6 V6 is pretty close to the Gen5 V8 on 1/4 mile performance.

I understand there are still concerns with the V8 AFM lifter, even now! So that's one point in favor of the V6.

[ADVMax]

and thus why I asked manual or auto.

you have decisions to make.

[NOT A 45]

Originally Posted by Rock-It Man

Thanks for the insight!

I have a 2010 that's going to get replaced by a Gen6 when the availability improves, and I'm torn between a V6 and V8.

The V8 AFM experience with my 2010 2SS was a bummer, even though the lifters were replaced at no cost to me. And the Gen6 V6 is pretty close to the Gen5 V8 on 1/4 mile performance.

I understand there are still concerns with the V8 AFM lifter, even now! So that's one point in favor of the V6.

I don't believe I'm writing this but......The turbo 4 with a manual will surprise you. With some ss wheels and spoilers it would make a great daily driver.

[Rock-It Man]

Originally Posted by NOT A 45

I don't believe I'm writing this but......The turbo 4 with a manual will surprise you. With some ss wheels and spoilers it would make a great daily driver.

Thanks! I bet you're right. An RS turbo 4 would be fun with a manual...if I wanted a manual.

I drove manuals only from age 16 to 50, give or take. Now approaching 70, I'm glad I don't have to worry about shifting into 2nd when I was aiming for 4th.

[morepowerjoe]

My son bought a 2021 turbo 4 cylinder auto, and it would actually get out of it's own way. It was very surprisingly peppy. My son is 18 years old and drove the shi* out of it for 6 months and no problems but there was a lot of metal in the oil but I assume it was just break in. He actually sold it back to the dealer for $2500 more then he paid for it and bought a c5 for really cheap.

[L6611983]

It started after I did the oil change I noticed only 5 1/2 quarts came out and I filled it back up with 8 quarts exactly this has never happened I didn't bother checking the oil dip stick after

[NOT A 45]

Originally Posted by L6611983

It started after I did the oil change I noticed only 5 1/2 quarts came out and I filled it back up with 8 quarts exactly this has never happened I didn't bother checking the oil dip stick after

I'm sure it was just a coincidence. Occasionally run into things like that in our shop. Customer comes in for a alignment and now all of a sudden their power seat stops working. Those lifters are a poor design, you just happened to reach the end of its life cycle when you shut it off to change the oil. Easy enough for me to say being a tech but I would just replace the 4 AFM lifters on the right bank and keep on driving.

[L6611983]

Wouldn't it be better if the AFM is removed completely? But what cam allows that to pass the California smog check?

[NOT A 45]

Originally Posted by L6611983

Wouldn't it be better if the AFM is removed completely? But what cam allows that to pass the California smog check?

We have similar emissions here in Maryland and I constantly have cammed cars coming in our shop. Fortunately here our emission test stations have a self service kiosk so no one is around to hear the car. As long as the ecm has run all the self tests and there's no trouble codes stored, it passes. A good tuner can make that happen.

[morepowerjoe]

Yeah but California checks the ecu for changes, how would he get around that with a tune? I'm assuming you will need a tune to turn off the afm and cam swap?

[L6611983]

I thought if the cam was CARB legal the tune didn't matter if it was changed in the ECU