2008 Tahoe New to me but have some issues

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BG1988

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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.
The alternator on my toyota corolla went at 89k.. can happen on any car... 103K on it now

had it rebuilt(not the pulley) the diode went on it though..

my pulley were the alternator goes on my tahoe is going out starting to wobble and make noise 121k miles. 45$ to replace (just replaced the tensionor )
 

BG1988

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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
needs the gen4 tahoe hybird corvette variable oil pump ..... were pushing 58-60psi at 1100+ rpm.. gotta keep the parts lubricated....
 
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Stage2Tahoe

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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.
I disabled the DOD/AFM with my HPTuners so it won't be coming back on. I did it to save the lifters and hopefully save the valvetrain. The reason for blocking the bypass is to help with oil pressure. It was suggested by a friend of mine that has been building LS motors since the early 2000's
 
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Stage2Tahoe

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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
Thanks for the positive outlook. Its hard going from one setup to another and seeing all of the different changes. Going from an 03 that shows steady voltage and oil pressure too the 08 has been nerve racking. Especially because of me having mechanical issues from the start. everytime I see something different it makes me nervous. I need it right so I can focus on getting the motor built for my 03 and get it tuned. Then I can take my time with the 08 and keep the mileage down on both.
 

EddieC

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Besides the usual maintenance items, our '08 has had front hubs, front struts, upper ball joints, and a rear end.
Mechanic said they are known for hubs needing replacement.
The only thing that really was a surprise was the rear end. And it was a struggle to get that straightened out starting with just replacing carrier bearings to a full rebuild and it still has a slight whine. Who would know it takes a doctorate to work on a differential.

Besides that it has been and is a great modern "sedan delivery".
All back seats were removed long ago and is a good dog hauler to shows and is big enough to sleep in traveling and camping.
 

dkmoneypit

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Thanks for the positive outlook. Its hard going from one setup to another and seeing all of the different changes. Going from an 03 that shows steady voltage and oil pressure too the 08 has been nerve racking. Especially because of me having mechanical issues from the start. everytime I see something different it makes me nervous. I need it right so I can focus on getting the motor built for my 03 and get it tuned. Then I can take my time with the 08 and keep the mileage down on both.
Dont forget about the drivers side motor mount. My 08 started leaking red fluid and it took me awhile to figure out it was the liquid filled motor mount. Didnt know there was such a thing. Replaced it with a H3 solid motor mount.
 
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Stage2Tahoe

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I know this isn’t engine/drivetrain related but I have had good feed back from you all. I have to replace the washer fluid tubing due to dry rot and need a full system. Has anyone had to do this? If so did you buy a kit or build yourself?
 

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