2.7 Turbo 4 Fan Club

[F-150stxguy]

Anyone know how the AFM operates on these engines as opposed to the 5.3 or 6.2? I’m guessing it’s pretty different considering this is an OHC. 
 

Also, can the AFM be disabled if I use tow-haul mode? 

[customboss]

1 hour ago, F-150stxguy said:

Anyone know how the AFM operates on these engines as opposed to the 5.3 or 6.2? I’m guessing it’s pretty different considering this is an OHC. 
 

Also, can the AFM be disabled if I use tow-haul mode? 

 

I'm not an expert but as I read my manual ; 

 

AFM is different on this unit, mostly mechanical, 3 levels of lift on slider cam actuation.  AFM is load dependent. If you are towing and its above a certain boost most likely you will be in high lift cam phase and won't kick in. 

 

As far as disabling manually I don't think you can. Its internal to the valve train design. Hand made in house by GM not contracted out like the DFM and AFM of the V8 and V6 versions. 

 

The videos and other descriptions describe it better than I can. 

 

 

[F-150stxguy]

1 hour ago, customboss said:

 

I'm not an expert but as I read my manual ; 

 

AFM is different on this unit, mostly mechanical, 3 levels of lift on slider cam actuation.  AFM is load dependent. If you are towing and its above a certain boost most likely you will be in high lift cam phase and won't kick in. 

 

As far as disabling manually I don't think you can. Its internal to the valve train design. Hand made in house by GM not contracted out like the DFM and AFM of the V8 and V6 versions. 

 

The videos and other descriptions describe it better than I can. 

 

 

Thanks. Hopefully this is inherently more reliable than its OHV AFM/DFM counter parts. 
 

The only concern I have is my commute would almost be 50 miles of very little stopping at 55mph, I could be on cruise almost the whole way. Seems like it would be prime territory for running in less cylinders. While I bet I would get amazing mpg, I would be worried about day after day and week after week of running on less cylinders. Maybe I would just need to make it a habit of stepping on it once in awhile lol. 

[KARNUT]

1 minute ago, F-150stxguy said:

Thanks. Hopefully this is inherently more reliable than its OHV AFM/DFM counter parts. 
 

The only concern I have is my commute would almost be 50 miles of very little stopping at 55mph, I could be on cruise almost the whole way. Seems like it would be prime territory for running in less cylinders. While I bet I would get amazing mpg, I would be worried about day after day and week after week of running on less cylinders. Maybe I would just need to make it a habit of stepping on it once in awhile lol. 

With my V-8 5.3 at 70 mph the cylinder deactivation only came on with  downhill grades. At 55 mph you’ll probably get more activation. While I hate cylinder deactivation on your engine I could dig it. At least there’s less parts to fail. Most people buy those with mileage in mind. I like the idea of that engine. I wish they’d left the 6.2 alone and made it more available. 

[customboss]

Correction, SAE says 430 ft lbs TQ. https://gmauthority.com/blog/2021/12/2022-chevy-silverado-turbo-2-7l-engines-torque-peak-could-be-even-higher/

 

[Mike Borowski]

Is anyone getting AWFUL gas mileage in the winter?  It's been in the 20's here in MI and my commute is just short drives around the city but 10,11,12 MAYBE 13MPG lately has me concerned.  In the summer, same commute I average 17-18.  

[Steve-2019]

13 minutes ago, Mike Borowski said:

Is anyone getting AWFUL gas mileage in the winter?  It's been in the 20's here in MI and my commute is just short drives around the city but 10,11,12 MAYBE 13MPG lately has me concerned.  In the summer, same commute I average 17-18.  

 

Winter blend fuel.

[Mike Borowski]

6 minutes ago, Steve-2019 said:

 

Winter blend fuel.

Yeah?  It’s that drastic?  Guess I never noticed. Engine runs a tad rougher too. Not bad just noticeable. 

[customboss]

1 hour ago, Mike Borowski said:

Is anyone getting AWFUL gas mileage in the winter?  It's been in the 20's here in MI and my commute is just short drives around the city but 10,11,12 MAYBE 13MPG lately has me concerned.  In the summer, same commute I average 17-18.  

Mine is garaged and until recently no difference. Once garage dropped to lower 30’s and OAT is teens to 0 ish  I notice a slight drop. 4 wheeling in snow to smash it down on the drive it got to 16 but it was fully warmed. 
I’m experimenting with 87 octane mix here where my regular fuel is 85. 
At 3082 miles on it I’m averaging nearly 21. 
I think the fuel map for colder ambient temps may be too rich. TBD. 

[customboss]

On oxygenates in the regional fuels mixes it can make a difference. However since this is turbo’d I’m doubting it’s that dramatic. 
Mike are you garaged or parked outside? 
Do you keep heater thermostat on cold until you see 185 F or higher in coolant? 
I warm engine literally above 185 in less than a minute  if I hold off moving heater knob full cold for that rise. If I move it up demanding heat it pulls coolant temp very close to 160 and stays there for 5+ minutes. That can trigger the fueling to stay too rich. The 3 valve electric coolant switch is really efficient and effective at cooling but temp rise is impacted by that. 
What brand and octane of fuel you using? 

[Mike Borowski]

23 minutes ago, customboss said:

On oxygenates in the regional fuels mixes it can make a difference. However since this is turbo’d I’m doubting it’s that dramatic. 
Mike are you garaged or parked outside? 
Do you keep heater thermostat on cold until you see 185 F or higher in coolant? 
I warm engine literally above 185 in less than a minute  if I hold off moving heater knob full cold for that rise. If I move it up demanding heat it pulls coolant temp very close to 160 and stays there for 5+ minutes. That can trigger the fueling to stay too rich. The 3 valve electric coolant switch is really efficient and effective at cooling but temp rise is impacted by that. 
What brand and octane of fuel you using? 

Unfortunately I park outside in the driveway. I use shell or marathon 87 octane. 
 

I’ve been having a slight little “hiccup” when coming to a stop and the last time I was on the highway. I don’t have any engine codes but I have had to have my MAF replaced and EVAP already I wonder if the MAF is going back again. 

[customboss]

4 minutes ago, Mike Borowski said:

Unfortunately I park outside in the driveway. I use shell or marathon 87 octane. 
 

I’ve been having a slight little “hiccup” when coming to a stop and the last time I was on the highway. I don’t have any engine codes but I have had to have my MAF replaced and EVAP already I wonder if the MAF is going back again. 

Could be an issue with the MAF or some water vapor that freezes on shut down.  More likely an air flow issue, which will amplify the fueling being rich in the cold. 

 

Have you ever changed the air filter since its pretty new? ANY restriction on that filter media will cause issues that won't throw any codes and cause what you are describing. 

 

Both Shell and Marathon have reasonably good fuel additives to keep things clean.  What other fuel brands are available?  Assuming 87 octane being used? 

[Mike Borowski]

1 minute ago, customboss said:

Could be an issue with the MAF or some water vapor that freezes on shut down.  More likely an air flow issue, which will amplify the fueling being rich in the cold. 

 

Have you ever changed the air filter since its pretty new? ANY restriction on that filter media will cause issues that won't throw any codes and cause what you are describing. 

 

Both Shell and Marathon have reasonably good fuel additives to keep things clean.  What other fuel brands are available?  Assuming 87 octane being used? 

Yeah it’s 87 octane. I might fill up with premium for S&G next fill up.

 

I had the AFE CAI installed for almost a year and had to have the MAF replaced. When I got the EVAP code, I put the stock intake back on out of fear the dealer was going to blame it on the intake.
 

I did somewhat recently put a K&N panel filter in. Ugh I’m worried without a CEL the dealer won’t be able to replicate it. 

[customboss]

1 minute ago, Mike Borowski said:

Yeah it’s 87 octane. I might fill up with premium for S&G next fill up.

 

I had the AFE CAI installed for almost a year and had to have the MAF replaced. When I got the EVAP code, I put the stock intake back on out of fear the dealer was going to blame it on the intake.
 

I did somewhat recently put a K&N panel filter in. Ugh I’m worried without a CEL the dealer won’t be able to replicate it. 

If me and I am speaking from 42 years of oil analysis experience that any air filter that needs to be serviced is a potential problem.  I raced for Oldsmobile and we were sponsored by K&N and they were crap. We threw them away after every 2-3 hour IMSA road race.

 

K&N were either over-serviced or under-serviced or leaked unfiltered air and either way you can restrict air flow, coat your internal sensors with oil. If under-serviced or improperly oiled where you duct unfiltered air  through you will damage things with dirt, dust, water condensate. 

 

AFE makes a good non cotton media for the throw away or water and detergent cleaned filters that are UN-OILED but it must be serviced perfectly and carefully. 

 

Ideally use paper OEM and change it often ( probably 10,000 miles or less)  to get good well sealed clean air flow. 

 

I would stick with 87 octane, not sure what S&G is? 

 

Would bet your mods to air filter/intake plumbing caused/contributed the MAF issue. 

 

 

 

 

[Mike Borowski]

****** & Giggles = S&G. 
 

So I started the truck and unplugged the cable to the MAF, the truck still ran. I shut the truck off and plugged it back in, now I have a CEL. It shouldn’t run unplugged should it?