2008 Tahoe New to me but have some issues

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Stage2Tahoe

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I purchased a 2008 tahoe Flex fuel thinking it was a good deal but already want my 03 fixed. I wanted to ask if there is anything I need to watch out for as I repair what is wrong. I bought it with 89000 on the odometer, but I have had problems since I got it home. So far I have disabled the DOD/AFM, Replaced the Oil pressure sensor, Sway bar links, front struts are coming and then Alternator crapped out on me on the way home from the lot I purchased it from. So saying I'm not happy is an understatement. This is the 1st and last time I will ever buy a vehicle from a smaller lot!

All of that being said... I am asking for any suggestions on thing that you have had to do. I felt that this would be the best way to get advice rather than trying to search for issues that I haven't dealt with yet. Thanks in Advance.
 

Fubar0715

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Any idiot lights on in the dash? Front hubs on mine were due in the 110-115k range and mine is 5years newer. Got an oil cooler - if so, check for weeping/drips of oil on the drivers side of the oil pan. Fluids change out since you have not history. Keep an eye on the oil pressure - the sender on the manifold is 1 area of concern for low pressure but the O-ring for the pickup tube is another gremlin.
 
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Stage2Tahoe

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I don't have any idiot lights on the dash. I had the SES pop up when the pressure sensor crapped out on Christmas. When you say sender are you referring to the oil bypass valve on the oil pan? If so I am planning to pull the pan and block it. While I am doing that I will change out the pickup o-ring. I haven't checked for an oil cooler, but I am going to speculate that it does not have one. Mine is the LS trim package. I am having issues with the power windows not wanting to work on the individual doors, but I can control them all from the drivers door, and the rear window defrost doesn't work. I have done an oil change though. After finding all of the other issues I couldn't trust anything that the lot should have done. I figured out they were just trying to move it quick, and I was the sucker that ended up with it.
 

Doubeleive

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I purchased a 2008 tahoe Flex fuel thinking it was a good deal but already want my 03 fixed. I wanted to ask if there is anything I need to watch out for as I repair what is wrong. I bought it with 89000 on the odometer, but I have had problems since I got it home. So far I have disabled the DOD/AFM, Replaced the Oil pressure sensor, Sway bar links, front struts are coming and then Alternator crapped out on me on the way home from the lot I purchased it from. So saying I'm not happy is an understatement. This is the 1st and last time I will ever buy a vehicle from a smaller lot!

All of that being said... I am asking for any suggestions on thing that you have had to do. I felt that this would be the best way to get advice rather than trying to search for issues that I haven't dealt with yet. Thanks in Advance.
sounds like the previous owner did not maintain it well, allthough none of the mentioned issues are out of the ordinary
the struts are known to start failing around 85k, it's even worse on the newer trucks 2015+ those start to fail around 45k
oil pressure sensor fails without warning on all sometimes even a new sensor fails in short order right out of the box
sway bar links on the gmt900's are pretty much a lot of plastic and they break and fall off (normal)
alternator's generally go twice that lifespan at least, typically you see them and various other things start fail at around 160k or so
once you get it all buttoned up though you should be fine for a good while. change all the fluids, coolant, brake, steering, trans, transfer case, rear diff.
since it is a 08 you might want to consider changing the heater hose's and T connectors, those will be next to fail simply due to age, the plastic weakens over time and they are known to just snap off and spit all the coolant out in nothing flat.
add some ground wires under the hood like a (big 3 upgrade) that might help with the windows, who knows,,,,,
 
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Stage2Tahoe

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I will check this stuff off. I looked at the chassis and everything is astonishingly clean. It was originally from Texas and spent some time in south Florida. It looks like it baked in the sun, but the paint is in great shape. I have found some of the plastics are all deteriorating. I am one for upgrading as parts fail so I will make it better. I can only sarcastically chuckle when I share what’s happening because the lot felt good about selling this turd in this condition. A person can only check so much in a lot. I do have one more question though. Oil pressure…. Where abouts should it be? Mine is at about 30 when up to temp and increases with rpm up to 40+ depending on driving conditions. Being a flex fuel vehicle it is a little different than my gen 3 vehicles.
 

Doubeleive

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I will check this stuff off. I looked at the chassis and everything is astonishingly clean. It was originally from Texas and spent some time in south Florida. It looks like it baked in the sun, but the paint is in great shape. I have found some of the plastics are all deteriorating. I am one for upgrading as parts fail so I will make it better. I can only sarcastically chuckle when I share what’s happening because the lot felt good about selling this turd in this condition. A person can only check so much in a lot. I do have one more question though. Oil pressure…. Where abouts should it be? Mine is at about 30 when up to temp and increases with rpm up to 40+ depending on driving conditions. Being a flex fuel vehicle it is a little different than my gen 3 vehicles.
oil pressure will vary on this gen from 40 down to 20 with a hot idle. that is 100% normal for it to move around. It was a bit hard for me to believe coming from a 00 with a solid 70psi and others that sat on 40 pretty much anytime
if it is dropping below 20 then you might have something going on the low oil pressure trigger is 10psi.
on these the oil pickup tube o-ring can be problemtatic causing the pump to suck in air when most of the oil is moving around already
usually happens from age. fixable with new o-rings and or/pickup tube, requires dropping the pan
 

j91z28d1

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the windows are probably just the switches if they work from the drivers door. cheap and easy to replace. mine had one bad when it got it and a buddy of mine was telling me he had a work truck of these gens back when they were new enough to be in their fleet and he said they replaced window switches all the time. tossed one in every glove box lol.

funny how every newer Gen seems to get worse in their fleet of about 20 trucks out surveying. crews fight over the older ls trucks as anything with an LT has been in and out of shops and randomly leaving them stranded around the state. so as much as your 03 was probably the most reliable gen engine wise, it does get worse than what you have now. you've got good oil pressure and dod deleted. from what I read a upgraded torque converter by around 140k and you're pretty solid.

definitely do those T's thou.
 
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Stage2Tahoe

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The driver side interior door handle has broken plastic so I will check all of the switches in it first and go from there. As for this whole journey.... I didn't want to buy this 08, but I was in a tough spot with the 03 going down. It lost either a rod bearing or a lifter. I had already started buying all of the parts to upgrade it to a 5.3 from the 4.8, but it didn't last. I can't complain though. I bought the 03 with 221k on it, and got just past 398k before the motor said NO MORE. I hope to get the 03 done buy summer, but have to spend my parts money on the 08.
 

iamdub

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I will check this stuff off. I looked at the chassis and everything is astonishingly clean. It was originally from Texas and spent some time in south Florida. It looks like it baked in the sun, but the paint is in great shape. I have found some of the plastics are all deteriorating. I am one for upgrading as parts fail so I will make it better. I can only sarcastically chuckle when I share what’s happening because the lot felt good about selling this turd in this condition. A person can only check so much in a lot. I do have one more question though. Oil pressure…. Where abouts should it be? Mine is at about 30 when up to temp and increases with rpm up to 40+ depending on driving conditions. Being a flex fuel vehicle it is a little different than my gen 3 vehicles.

Going by your posts in this thread, it sounds like it might've been owned by an older person or couple and not driven a whole lot. The issues you've had are all very common items for these things, especially one that doesn't get used often. The alternator crapping out is about the only oddity.

Some Gen 3 vehicles were Flex Fuel. About the only thing unique with your Gen 4 is it having AFM, which you've disabled. Honestly, I wouldn't plug that pop-off valve in the oil pan unless you had AFM disabled in the tune or deleted (mechanically). If you're using a plug-in module, and you removed it for whatever reason and AFM is restored, it'd really mess up some things the first time AFM engaged.
 

Dustin Jackson

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@Stage2Tahoe Hey buddy sorry to hear you encountered some hangups when you first got the Tahoe but all of those things can be fixed very cheap if you do it yourself. Some of the downsides of a lower mileage vehicle is that some of those components wear faster when not in use. Low miles can mean that it sat for most of its life and the rubber and other wear materials degrade faster.

Stay positive and I think you will be happy when it's dialed in.

I bought my Tahoe with 160,000 miles on it and had to immediately redo the entire suspension and then after having it for 2 years I had a lifter failure but after all that I can say I love this thing
 

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