2007 Tahoe/New member from sunny California/Looking for some advice

[wsteele]

Thank you for more helpful info. Yes, the 8th number is a zero, and any VIN check website says FF. No yellow cap, no emblem. I'll take a pic of the glove box sticker today to see if I can get help from GM.

Husband is not the best with keeping up on oil changes...I try to not nag, but I may have to if we want to keep this Tahoe lol. Due to the AFM issues, what do folks recommend for the mileage to change oil (if different than what the manual calls for)? Thanks!

I change my 2007 Yukon's oil every 5K (have since new). I use a quality full synthetic 5W30 and a filter with each change.

If yours is flex fuel, although E85 stations are normally rare as hens teeth out west, they usually offer pricing on par with Costco's best for Regular. The engines seem to work pretty well with it. The stuff burns pretty clean.

 

[swathdiver]

Thank you for more helpful info. Yes, the 8th number is a zero, and any VIN check website says FF. No yellow cap, no emblem. I'll take a pic of the glove box sticker today to see if I can get help from GM.

Husband is not the best with keeping up on oil changes...I try to not nag, but I may have to if we want to keep this Tahoe lol. Due to the AFM issues, what do folks recommend for the mileage to change oil (if different than what the manual calls for)? Thanks!

You're welcome, we're delighted to help. It's possible the owner took the emblems off or they were discarded if the truck was painted. Do get the proper gas cap, 20915990 when you can.

Run full synthetic oil and change it every 5K miles. The computer system's Oil Life Monitor will run an oil change out to about 7,500 miles. The original oil specified for these was a blend which was later changed to full synthetic. When my truck hits about 5,000 since the last oil change, the OLM is showing about 33% oil life left. It varies a little depending on the kind of driving we were doing.

To make sure things are good where I cannot see, the health of the inside of the engine and transmission, I send off oil samples of each fluid for analysis every year or so to Blackstone Labs and thankfully, all is well for both since we bought it.

My front differential's ring and pinion gear is loud too, the windows are up with the AC running most of the time and if the radio is on low it can certainly be heard. I'll get around to rebuilding it one of these days. As long as there are no chunks of metal on the drain plug magnet, feel free to kick that can down the road.

 

[Caligirl]

Oh and regarding the battery, see if you can find a date code. If it's much older than 5 yrs, I'd consider replacing it. Our 2011 Suburban had a 2015 battery that would die after leaving interior lights on for 30 min. And a battery tester said it was "good"...$150 later from Costco and we're good for the foreseeable future. Not fun to have a dead battery in the middle of nowhere.

Appreciate the tip. Tomorrow we will be looking at the Tahoe more carefully to try to determine if we want to take a gamble and keep this 2007. I'll see if we can find a date. It is an ACDelco brand. Not too expensive for new battery, so hopefully that is the problem. Hate to decide to keep this vehicle and then have random "no start" mornings with a new battery. Don't want to go down that rabbit hole!

 

[Caligirl]

You're welcome, we're delighted to help. It's possible the owner took the emblems off or they were discarded if the truck was painted. Do get the proper gas cap, 20915990 when you can.

Run full synthetic oil and change it every 5K miles. The computer system's Oil Life Monitor will run an oil change out to about 7,500 miles. The original oil specified for these was a blend which was later changed to full synthetic. When my truck hits about 5,000 since the last oil change, the OLM is showing about 33% oil life left. It varies a little depending on the kind of driving we were doing.

To make sure things are good where I cannot see, the health of the inside of the engine and transmission, I send off oil samples of each fluid for analysis every year or so to Blackstone Labs and thankfully, all is well for both since we bought it.

My front differential's ring and pinion gear is loud too, the windows are up with the AC running most of the time and if the radio is on low it can certainly be heard. I'll get around to rebuilding it one of these days. As long as there are no chunks of metal on the drain plug magnet, feel free to kick that can down the road.

Thanks for all the info. Figured I'd pick the minds of those who have already dealt with Tahoe issues. So hard to drive a "new" used vehicle and not know what is "normal." Very well may be doing and sounding exactly like it's supposed to.

Figured I could get a newer Tahoe with similar mileage and less known issues for that year, think I'm dodging the bullet, but I know I just can't predict what any vehicle will do. May have no issues with this one and have trouble with a newer one. We considered a 2012 LTZ with 57k that the guy dropped 5k off KBB price because the rear autolift gate was fried. And had a cracked dash. Made us wonder what other things may be in store on this super nice, newer, low mileage Tahoe with so many bells and whistles. Just hate to trade my reliable, boring Camry for a silent trouble maker. Where is my crystal ball when I need it?

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Some folks here have more patience than others, but the accumulated knowledge and experience of this group is stellar. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

More pics, please.

 

[iamdub]

...We found a sweet deal on a 2007 Tahoe LT 4x4, correct color (white), one owner, garaged with 87,000 miles for 10k. Estate item, so no real info besides what daughter told us about how it was treated. Garaged by retired farmer with dogs (more on that later...) No service records, but hubs said very clean and well-kept and doesn't look 14 years old, no visible rust, etc. They had the 90k servicing done end of 2020 at a dealership for $1800 (wow!) including new spark plugs, wires, elements, fluid, flush etc. No repairs recommended but new wipers all around. Besides a few cosmetic concerns, very clean. We jumped on it, figuring we couldn't lose if we decided to turn it if it is not what I want.

Sounds like a great deal!

Looking for some advice and info before we decide if this is the one I want, or turn it and keep looking. Keep or sell, we need to do a little bit of minor stuff on it (and possibly more than minor if I keep it) I will not sell the Camry until I have another vehicle I'm keeping. Although I am not the one doing the maintenance and such, I am the research and shopping queen, so finding out the pros and cons of the various Tahoes and if there are enough questions with this one, may look for a 2009-2012 that has the 6 speed (I think that is the year it starts being 6 speed) and maybe built in blue tooth etc and supposedly some of the mechanical issues improved upon.

Yes, '09+ has the 6-speed. I believe the exception is the PPV got it in 2010+. Factory Bluetooth isn't all that special. It's for phone calls only. My personal recommendation is to get an aftermarket HU and you'll have tons more features, phone and music streaming via Bluetooth (or Wi-Fi if you get a fancy enough HU) and better sound. Other than the better trans, about the only real mechanical issues that were improved upon was the AFM components and the driver's side rocker cover.

Stuff I gleaned from here and elsewhere.

First of all, the VIN says I have a LMG engine, but there is NOTHING on the gas cap or on the vehicle that indicates flex fuel. I understand that some parts for FF are more expensive (even though I won't be using it, the maintenance cost will be part of my decision making) The part number for the spark plugs at the last service is 19417955. Can anyone tell from that if it is a FF? And if not, is there a way to look at the engine to tell????

The gas cap may have been replaced with a non-FF OEM or aftermarket. I believe the only difference is the color. The only way to tell if it's FF by looking at the engine is to ID the injectors. You can double-check your build specs by looking at the RPO label on the inside of the glove box lid. Look for "LMG".

Second, I have read ad nauseum about the AFM issue. I won't belabor upon that and how often it happens blah blah blah. But I DO want to know clearly if putting on a disabler involves any other steps. Again, in my research, if you plug one in under the dash, some say you have to do other things under the hood to compensate for that change because of other things I don't understand (okay, I'm gonna show my ignorance on such things now!). Is it as simple as plug and play? Or will other things need to be done. Please point me to specific links on here that will help

Your '07 came with the "first and worst" iteration of AFM. There's a chance the parts were updated, though. They improved the VLOM and lifter designs to greatly increase reliability. Since yours is low-mileage, you're in a great position to disable it and let it ride. My personal recommendation is to have it tuned out. You can get someone local to do this and it'd likely be at least $150, which is still cheaper than the plug-in module options. Or, you can send the PCM to this guy and have it done for about $70 or less, depending on shipping. If you wanna splurge, get a full custom tune by someone who specializes in these (such as Black Bear) and you'll get all kinds of improvements from better drivability from more responsive throttle and shifting characteristics to increased trans life. Above all, use quality oil and change it regularly, before it gets too nasty. My experience shows that 5,000 miles is a good OCI for when the oil starts to get dark. Use of a quality full synthetic oil and good filter is paramount.

Third, I think the door latch is bad (or clogged with dang dog hair!), as the dome light never goes on with driver door opened, and the radio does not go off when I have the key out of the ignition and open and close the driver door (tried the passenger door, too, radio stays on, but light works). Is that something my maintenance-minded and inclined husband can easily do? Again, links appreciated!

As this is a common problem, you're suspicions may be correct. Nobody here knows your husband's mechanical aptitude. But, I'd rate replacing the door latch as a "3" on a 1-10 scale. Somewhere above an oil change but a under a brake job, if that tells you anything.

Fourth, had the battery die on me a week or so after purchasing. Was sitting for maybe a day or two. Zilch, nada, nothing. Couldn't open with fob even. Husband charged for a few hours, started right up. Tested after sitting for over 24 hours with a fancy electronic tester thing from his work, and it said "bad" but I haven't had issues since with driving it daily, and sitting on weekends. Any idea if this relates to issue number 3? We also realize my husband may have accidentally turned the 4wd knob instead of the light knob and we had it in "auto" instead of 2wd. Could that do anything weird? Not using Onstar. No after market alarms. Really not many extras. Looks to be Bose (original probably) radio. Could really be just going bad, or some phantom draw is making it "bad." Oh the joys of learning "new to me" vehicles.

Batteries often show their faults when the weather changes, especially from warm to cold. Did it fail during a cold snap in your area? It may charge up and hold enough voltage to start and run it and seem "okay", but it could have an internal fault that the fancy electronic tester could see. Of course, there could be other possibilities. You can do a simple test with a DVOM (digital volt/ohm meter) to see if there's a steady drain and on what circuit. You set the meter up to read amps, disconnect the negative cable from the battery, put one of the meter's leads on the battery post and the other lead on the cable. Take note of the amps (should be milliamps). If they're high, remove one fuse at a time until the measured draw plummets. This will be the circuit that has the drain it. Be aware that, out of the many computers in this thing, some are still active long after the key is turned off and removed and the doors are shut. Some may reawaken from the disconnect and reconnecting of the battery, even if through the DVOM.

Fifth, all my Subs were 2wd, so no idea about 4wd, but there is a definite slight hum when going over 30 or 40 mph (in 2wd). When sitting in driver's seat, can hear pretty well, but not when in passenger. Not real loud and if radio on, can't hear at all. I also read that rear end stuff and other terms I don't remember are a thing on Tahoes in general that will require replacing, but given the mileage and everything else, is that something that should affect our decision making process, money wise?

Could be tires, trans, front or rear differential, hubs, etc. Make sure it's not in 4WD (neither 4HI nor 4LO).

 

[Caligirl]

Sounds like a great deal!




Yes, '09+ has the 6-speed. I believe the exception is the PPV got it in 2010+. Factory Bluetooth isn't all that special. It's for phone calls only. My personal recommendation is to get an aftermarket HU and you'll have tons more features, phone and music streaming via Bluetooth (or Wi-Fi if you get a fancy enough HU) and better sound. Other than the better trans, about the only real mechanical issues that were improved upon was the AFM components and the driver's side rocker cover.




The gas cap may have been replaced with a non-FF OEM or aftermarket. I believe the only difference is the color. The only way to tell if it's FF by looking at the engine is to ID the injectors. You can double-check your build specs by looking at the RPO label on the inside of the glove box lid. Look for "LMG".




Your '07 came with the "first and worst" iteration of AFM. There's a chance the parts were updated, though. They improved the VLOM and lifter designs to greatly increase reliability. Since yours is low-mileage, you're in a great position to disable it and let it ride. My personal recommendation is to have it tuned out. You can get someone local to do this and it'd likely be at least $150, which is still cheaper than the plug-in module options. Or, you can send the PCM to this guy and have it done for about $70 or less, depending on shipping. If you wanna splurge, get a full custom tune by someone who specializes in these (such as Black Bear) and you'll get all kinds of improvements from better drivability from more responsive throttle and shifting characteristics to increased trans life. Above all, use quality oil and change it regularly, before it gets too nasty. My experience shows that 5,000 miles is a good OCI for when the oil starts to get dark. Use of a quality full synthetic oil and good filter is paramount.




As this is a common problem, you're suspicions may be correct. Nobody here knows your husband's mechanical aptitude. But, I'd rate replacing the door latch as a "3" on a 1-10 scale. Somewhere above an oil change but a under a brake job, if that tells you anything.




Batteries often show their faults when the weather changes, especially from warm to cold. Did it fail during a cold snap in your area? It may charge up and hold enough voltage to start and run it and seem "okay", but it could have an internal fault that the fancy electronic tester could see. Of course, there could be other possibilities. You can do a simple test with a DVOM (digital volt/ohm meter) to see if there's a steady drain and on what circuit. You set the meter up to read amps, disconnect the negative cable from the battery, put one of the meter's leads on the battery post and the other lead on the cable. Take note of the amps (should be milliamps). If they're high, remove one fuse at a time until the measured draw plummets. This will be the circuit that has the drain it. Be aware that, out of the many computers in this thing, some are still active long after the key is turned off and removed and the doors are shut. Some may reawaken from the disconnect and reconnecting of the battery, even if through the DVOM.




Could be tires, trans, front or rear differential, hubs, etc. Make sure it's not in 4WD (neither 4HI nor 4LO).

Thanks for all the awesome answers! Learning curve for sure about this particular vehicle (especially for a non-mechanically minded person like me). But husband has done oil changes and breaks and more complicated work on older engines (that didn't involve so much computer components) so sounds like it shouldn't be too hard for him to figure out the door issue.

Still struggling to know the difference between the different options for AFM solutions. You mentioned a few and besides the plug-in disabler, the other options are over my head. Any handy links I can share with my husband regarding the different options? He has yet to be blessed with reading all the items he will be fixing or farming out

 

[wsteele]

Thanks for all the info. Figured I'd pick the minds of those who have already dealt with Tahoe issues. So hard to drive a "new" used vehicle and not know what is "normal." Very well may be doing and sounding exactly like it's supposed to.

Figured I could get a newer Tahoe with similar mileage and less known issues for that year, think I'm dodging the bullet, but I know I just can't predict what any vehicle will do. May have no issues with this one and have trouble with a newer one. We considered a 2012 LTZ with 57k that the guy dropped 5k off KBB price because the rear autolift gate was fried. And had a cracked dash. Made us wonder what other things may be in store on this super nice, newer, low mileage Tahoe with so many bells and whistles. Just hate to trade my reliable, boring Camry for a silent trouble maker. Where is my crystal ball when I need it?

On the "finding a newer model with less known issues" theme, I recently went through a similar decision process. I found a 2014 clone of my truck at a Buick dealer in St Helena, CA. It was a local Napa Valley truck all its life (no rust worries) and was in seemingly perfect shape (like mine), a little over 100K on the odometer. They wanted $20K for it, probably would have taken $19K. I almost flew out to take a look and buy it if it looked as good in person, but checked for the service history. There were only a few records on Carfax and the dealer had no online history in his DB.

My truck is using no measurable oil since the updated valve cover and the AFM pressure relief valve deflector were installed. I think I know most of the possible peccadillos that might crop up and I will be hard pressed to spend the difference in what mine is worth versus what the later model will cost me if every single peccadillo does rear its ugly head.

So for me, the devil you know thing seems right. I decided to stand pat and stay here for good advice going forward.

 

[iamdub]

Still struggling to know the difference between the different options for AFM solutions. You mentioned a few and besides the plug-in disabler, the other options are over my head. Any handy links I can share with my husband regarding the different options? He has yet to be blessed with reading all the items he will be fixing or farming out

Sounds like you two are plenty competent and capable. I can tell that, although you may not know some things, you're at least not afraid to search for the knowledge. TYF has your back.

Still struggling to know the difference between the different options for AFM solutions. You mentioned a few and besides the plug-in disabler, the other options are over my head. Any handy links I can share with my husband regarding the different options? He has yet to be blessed with reading all the items he will be fixing or farming out

There's disabling it then there's deleting it. Disabling is just having it turned off electronically so it doesn't engage. Deleting it is going into the engine and replacing the AFM components with their non-AFM counterparts- mechanically deleting it so that it's like it never existed.

The AFM system, primarily the lifters, has a lot of small moving parts that are more susceptible to failure than the non-AFM parts. Ever heard of an engine having a "collapsed lifter"? In a regular engine, this is a bad thing. But, it's actually how AFM operates. AFM works by collapsing the lifters in four of the engine's eight cylinders so the valves don't operate, making them dead cylinders and the engine runs on four cylinders. When the power is needed, the system pumps the lifters back up with oil so they operate the valves again, returning the function of those four cylinders.

This repetitive collapsing and filling of the lifters presents extra wear and failure points. By disabling AFM, the lifters stay pumped up so they operate like the other regular lifters. Stopping their operation is almost like freezing them them from aging, or at least, slowing it down. Disabling could last for tens of thousands of miles, maybe 100,000 miles, maybe more. But, due to the lack of "solid" parts (as compared to a regular lifter), there's still the elevated chance of an AFM lifter failing. These usually give some sort of indication that something is on its way out and it's time to start planning the permanent fix- a delete.

The options for disabling are to buy a module (such as the Range) that plugs into your ALDL ("OBD") port or to have it turned off in the PCM's tune. I don't know exactly how the plug-in module works, but it tells the computer something that makes it not activate AFM. I'm thinking it just alters one or some of the parameters required for the PCM to engage AFM. Anyway, while this is an easy option as you simply plug it into the port, it has a few drawbacks. Some of these may have been addressed, though. The drawbacks I'm familiar with are that it draws power and it's recommended that you unplug it if the vehicle will be parked for extended periods. I don't like anything unnecessarily drawing off my battery, even just over night, nor do I wanna have to remember to unplug something if I'm gonna park it for a while. Then, I'd have to remember to plug it back in. What if I forget and hit the road? Those AFM components that have been sitting dormant for X amount of time are suddenly recommissioned. Maybe nothing will happen, maybe something will. Removing it also resets your readiness monitors. So, if your locale requires vehicle inspections and they need to plug into your ALDL port, you're gonna have to remove the disabler hundreds of miles in advance and drive around until all of the monitors are readied so you'll pass inspection. There, again, you're reawakening a system that has been inactive for X amount of time and who knows what, if anything, will happen. The other big drawback is the $200 price. Used ones tend to go for $100-$150.

I believe that the other option for disabling, turning it off in a tune, is the best method. It can be done for as little as $50 plus shipping costs of your PCM or it can be done as part of a custom tune from $100 to $500 or more. That link I posted in my previous reply is the place to get it done for $50. I had a local speed shop disable mine along with a few other small tweaks (turning off the rear O2 sensors, removing the speed limiter, etc.) for $150. Doing it this way makes it like the system doesn't exist as far as your PCM is concerned. The only existence of AFM is the mechanical parts are still in the engine. This doesn't affect emissions or readiness monitors, etc.

Since you would really benefit from a custom tune, my suggestion is to find a good reputable local tuner or contact Black Bear to clean up your factory tune. They can disable AFM while they're at it. Or, if you just want the cheapest but sound solution, check out that link I posted.

 

[donjetman]

Wow Chris/iamdumb!!! You've become a novelist like Carla/callgirl