04 Z71 Should I tune it?

[Reuben0524]

Ok, so Im kinda new to tuning in general and I wanna know a good programmer/tuner to buy because I want to get more MPG and generally more power from the 5.3 but Im kinda unsure due to it having 290,000 miles on it. Should I tune it, if so which programmer should I buy.

 

[rockola1971]

290k? What you need first is a new or reman long block if you plan on running your engine hard. Not saying current engine wont last longer than it already has but its days are numbered. I personally have both a 5.3L and 6.0L over 300k now.

 

[Reuben0524]

290k? What you need first is a new or reman long block if you plan on running your engine hard. Not saying current engine wont last longer than it already has but its days are numbered. I personally have both a 5.3L and 6.0L over 300k now.

Thanks for the advice, Im not exactly planning to run it hard but a hp/torque boost will be nice and some MPG improvements. This is my first truck, and I my longterm goal is to make it look brand new of the lot in 04 and have it a little bit more power. I have another question have you had any major drivetrain issues after 300k?

 

[swathdiver]

Thanks for the advice, Im not exactly planning to run it hard but a hp/torque boost will be nice and some MPG improvements. This is my first truck, and I my longterm goal is to make it look brand new of the lot in 04 and have it a little bit more power. I have another question have you had any major drivetrain issues after 300k?

Have BlackBear tune it. He has the expertise, you and me don't. He's tuned 2 of mine so far. My Gen IV 5.3 puts down 315 horsepower to the rear wheels through the traps in the quarter mile and the tune is its only mod.

@BlackBearPerf

 

[Trey Hardy]

Ok, so Im kinda new to tuning in general and I wanna know a good programmer/tuner to buy because I want to get more MPG and generally more power from the 5.3 but Im kinda unsure due to it having 290,000 miles on it. Should I tune it, if so which programmer should I buy.

Black bear or a good local tuner who used HP tuners is the best any canned tuners suck and can cause issues.
I’ve personally always used HP tuners and always made a night and day difference
Anything I’ve tuned has had over 250-350,000 miles no issues and I run them pretty dang hard regularly

 

[Trey Hardy]

Thanks for the advice, Im not exactly planning to run it hard but a hp/torque boost will be nice and some MPG improvements. This is my first truck, and I my longterm goal is to make it look brand new of the lot in 04 and have it a little bit more power. I have another question have you had any major drivetrain issues after 300k?

Transmission will likely be the first to go them older 5.3s would last forever as long as you changed the oil but shit my uncle and father in law both had ones with over 400,000 miles on the original powertrain with nothing done to them besides a new battery and brake pads lol

 

[strutaeng]

1. Yeah, my thoughts too. Save the money for a transmission overhaul. You'll need one, if it hasn't already had at least once before.

2. Engine sounds good, but getting up there in miles. Maybe a valve stem seals is a good idea down the road? Run a compression test and leak-down test to see general valves and piston rings sealing performance.

3. I'm not sure on the programming. It's either a mail-order custom tune or learn to mess around with HP Tuners yourself. I don't know about the torque management stuff on the tune, a lot of folks remove that, but I think that stresses the transmission even more. See 1.

 

[rockola1971]

Thanks for the advice, Im not exactly planning to run it hard but a hp/torque boost will be nice and some MPG improvements. This is my first truck, and I my longterm goal is to make it look brand new of the lot in 04 and have it a little bit more power. I have another question have you had any major drivetrain issues after 300k?

HP/Torque Boost and better MPG dont usually happen at the same time. You get to choose one way or the other. The K chassis is not a racecar platform unless specifically built for the track. I havent had any drivetrain problems other than Tcase grenading but I got all 3 of my K chassis used with 240k, 252k and 290k on the odometer so I dont know any history on them. The wife's tahoe Tcase chain was stretched and ate into the case and come a peeking out. Yours has relatively high mileage, do you know any of its history? Things will start letting go 250k-310k so I would plan on tranny rebuild, Tcase rebuild and even the engine in your scenario. Wouldnt doubt the the front axle and even the rear axle need some attention. Also the frontend suspension likely need totally rebuilt. But it all depends on who had it before and what kind of maintenance they put into it and what it was used for (towing, family hauler, mountain and hills daily, hot/cold climate, road salt midwest, and ...............

 

[Marky Dissod]

Can't have MpG improvement AND horsepower / torque boost on a 300k mile engine at the exact same time.
If you drive Miss Daisy, MpG'll improve, moreso if you stay in 4th with TCC locked and your right foot stays CALM.
If you drive to work or play HARD, best your engine and transmission are both physically ready -
go over both with fine tooth combs.

If well-tuned for 89 or 91 octane, more MpG improvement OR more horses / torques are possible -
but not at the same time, depends how you are driving in the moment, see above.
The smaller the premium for 89 or 91 over 87, the more this will make sense for your wallet.

Too many people assume tunes are ONLY for releasing/increasing 'performance',
then narrowly define 'performance' as something they don't care for or about.
A 5.3L V8 that does what every other 5.3L V8 does while getting better MpG than the others, performs better, no?
It needn't be faster / quicker / whatever aspect they see as beneath or beside their narrow stereotype.

How do YOU define performance?
If you talk to your tuner about THAT definition -
- instead of asking those who prejudicially conflate tuning with a behavior they avoid -
- and have your pcm tuned to suit your tastes, it'll be the best money you'll've ever spent ...

unless your engine and/or transmission fail too soon.
So go over both with fine tooth combs.