AFM

[Fefanatic]

For those that installed a afm disabler. Have you had any oil pump issues? I'm doing the research and see that if the afm is disabled the oil pump bypass will be running wide open. So, has anyone had an oil pump fail under those conditions? I am 70 years old and do not want to drop an oil pan to replace an oil pump. I bought this clean, one owner, low mileage Tahoe and I don't like the performance from the engine as it is.

 

[Doubeleive]

For those that installed a afm disabler. Have you had any oil pump issues? I'm doing the research and see that if the afm is disabled the oil pump bypass will be running wide open. So, has anyone had an oil pump fail under those conditions? I am 70 years old and do not want to drop an oil pan to replace an oil pump. I bought this clean, one owner, low mileage Tahoe and I don't like the performance from the engine as it is.

not really any reported failures from use, the only thing that happens in general with the oil pumps is the pickup-tube o-ring can degrade and cause it to suck air.
this is due to age more than anything.

 

[tom3]

I can't imagine the oil flow control for the lifters would have any effect on the actual engine oiling or the oil pump load/

 

[Foggy]

Disable the dang DOD and drive on. You will be doing what is possible
electronically to extend the life of your cam/lifters.
I can't see any reason it would affect the "oiling" system negatively in any way

 

[mikez71]

You might consider having the ECM programmed. (cheaper and no chance of accidentally unplugging it)

Spending a bit more, transmission tuning can help with the boggy feeling. (at least with a 3.08 rearend)

 

[me51]

Directly turning off AFM in the ECM is probably the better choice. The Range AFM adapter can cause hard transmission shifting after some time, you can find multiple posts about it when googling.

 

[buckwild27]

For the time being till you get it tuned unplug the sensor wire in the brake booster vacuum line. It will prevent it from going into 4cyl mode. You will have a check engine light on because it can't find the sensor, but it doesn't cause any Drivability, issues. That sensor is what tells the truck that it is okay. And has enough vacuum to go into 4 cylinder mode. Then when you go to get it turned off in a tune you can plug it back in. Also if you change out the cam and lifters then you can delete the vacuum pump which also has it's downfalls because you won't need it anymore after you eliminate the AFM.

 

[Marky Dissod]

For the time being till you get it tuned unplug the sensor wire in the brake booster vacuum line. It will prevent it from going into 4cyl mode.
You will have a check engine light on because it can't find the sensor, but it doesn't cause any driveability issues.
That sensor is what tells the truck that it has enough vacuum to go into 4 cylinder mode.
Then when you go to get it turned off in a tune you can plug it back in.
Also if you change out the cam and lifters then you can delete the vacuum pump which also has it's downfalls because you won't need it anymore after you eliminate the AFM.

How much cheaper is this than a plug-in???

 

[buckwild27]

How much cheaper is this than a plug-in???

Unplugging the sensor is free. Having the engine and transmission tuned and turning off the AFM, I think that is dependent on what your local tuner guy charges. Rough guess $400-$600.

 

[j91z28d1]

For the time being till you get it tuned unplug the sensor wire in the brake booster vacuum line. It will prevent it from going into 4cyl mode. You will have a check engine light on because it can't find the sensor, but it doesn't cause any Drivability, issues. That sensor is what tells the truck that it is okay. And has enough vacuum to go into 4 cylinder mode. Then when you go to get it turned off in a tune you can plug it back in. Also if you change out the cam and lifters then you can delete the vacuum pump which also has it's downfalls because you won't need it anymore after you eliminate the AFM.

you've truck has a vacuum pump for the afm?

 

[buckwild27]

you've truck has a vacuum pump for the afm?

14-18 sierra/silverado and the 15-20 tahoe/yukon for sure have vacuum pumps to increase vacuum for when it is in 4 cylinder mode. the 07-14 doesn't have them. I'm just use to working on the newer one's so vacuum pump info is of no use here.

 

[j91z28d1]

14-18 sierra/silverado and the 15-20 tahoe/yukon for sure have vacuum pumps to increase vacuum for when it is in 4 cylinder mode. the 07-14 doesn't have them. I'm just use to working on the newer one's so vacuum pump info is of no use here.

interesting.

I guess they run in 4cyl mode much more often.


man the junk yards are going to be littered with LT's soon and the aftermarket isn't really embracing them either.


what a waste.

 

[mikez71]

Unplugging the sensor is free. Having the engine and transmission tuned and turning off the AFM, I think that is dependent on what your local tuner guy charges. Rough guess $400-$600.

$50 to just disable AFM here-> https://www.lt1swap.com/afm_delete.htm

 

[buckwild27]

interesting.

I guess they run in 4cyl mode much more often.


man the junk yards are going to be littered with LT's soon and the aftermarket isn't really embracing them either.


what a waste.

For me when the 5.3l kicks the bucket I'm swapping in a l8t it doesn't have AFM on it.

 

[Charlie207]

For me when the 5.3l kicks the bucket I'm swapping in a l8t it doesn't have AFM on it.

How are you going to control that 6.6?

 

[buckwild27]

How are you going to control that 6.6?

You can get the l83 ecm tuned for the L8T. Several people have done it already.

 

[Jazzmanfla]

Directly turning off AFM in the ECM is probably the better choice. The Range AFM adapter can cause hard transmission shifting after some time, you can find multiple posts about it when googling.

Void the warranty????

 

[Charlie207]

Void the warranty????

Warranty is long gone on any GMT900 by now.

 

[Charlie207]

You can get the l83 ecm tuned for the L8T. Several people have done it already.

Isn't the L83 for 2015+, which is a different engine.

My 2014 is an E38 PCM, for example.

 

[buckwild27]

Isn't the L83 for 2015+, which is a different engine.

My 2014 is an E38 PCM, for example.

Yes you're right. I'm going to be doing the swap on my sierra which is 14-18 not 15-20 like the tahoe and yukons