xj on the chopping block, bought a '01 2500 suburban. Update! I could use some help

[dfarm]

Hey guys. We've outgrown the old trusty xj, did the minivan thing for a few months, then decided that it didn't fit our lifestyle too well, then the suburban fell into our laps.

It's got the 6.0, auto, tons of power options, tow package, factory lsd (k80 option iirc), and what appears to be about 6"of lift and 35x12.5's on 17" wheels. I also have a dual fox shock setup for the front that isn't installed because the p/o changed the upper control arms because of bad balljoints and the lower mounts for the shocks are welded onto the control arm.

This is my first gm product, and my first 4x4 that doesn't have a live axle in the front.

I was curious what spare parts to start gathering, and what some common points of failure are that I should keep an eye on.

The only faults I notice right now are an oil leak that appears to be from the right VC and the left side of the oil pan( it doesn't appear that these will be terrible to fix) there is a "service suspension soon" message in the gauge cluster, which I'm 99% sure is from not having the "active" struts on it anymore. And some of the electronic options inside aren't working.

My plans so far include getting a few more floor anchors for the cargo area, building some storage "racks" to go over the quarter glass inside the back, and front and rear bumpers, probably with a winch on the front, and a swingout for a spare tire on the back, as well as some lighting.

Also, we're seeing about 11.5mpg right now, is this about right? I'm not sure if it was ever re programmed for the bigger tires or not.

Thanks in advance!

 

[superbuickguy]

11 is about right with 35s and a 6" lift - good thing you've got a 40 gallon tank, right?

Those Suburbans are bulletproof, however, if you go any bigger on the tires you'll want to keep control arms in stock - especially upper ones. Of course, it all depends on how you drive it - if you hammer your way down every trail, stuff will break. Nice part of IFS is they ride and drive so much better on rough roads than solid axles.

I've got dual shocks on a solid axle rig, and have had them on several rigs - and, unless the tire size is approaching 40" and/or a heavy brush guard and winch, I'm not convinced that they're necessary - and worse, they make the ride worse because the front is now stiffer than the rear (it feels like your tush is bouncing but your feet are staying in one place). On the Suburban, who already have tail-dragging tendencies - the feeling is even worse. If you do upgrade the front shocks, be certain you level the rear and add comparable shocks. I personally feel the ride of the 'burb is too cushy, so stiffening it up a bit is a good thing.

The 6.0 only has one common issue - the intake can start leaking cooling fluid. If you start getting a smell, odds are, that's the problem. The rest of the drivetrain is pretty standard, built-for-a-decade stuff.

You might be able to get that light turned off if you have a Tech2 computer - as that suspension was optional, and it's not Fed-mandated requirement.

Oil leaks, ugh. With any GM motor, be certain you know where the leak is coming from before you dig in. Often the leak is a sensor that's failed rather than a main (valve cover or pan) leak.

Enjoy your new rig, there's good reasons why Suburbans own 75% of the market.

And finally, acquaint yourself with a set of articles written by Rick Siemans called "The Wanderers"... fictional account of a retired Navy couple travelling the US in a Suburban on 44s with every creature comfort available.... he was overland before overland was cool.

 

[dfarm]

Thanks for that info.

Can anyone recommend a tuner for this truck?

Also, is the corvette shift solenoid upgrade worth doing?

Thanks again!

 

[superbuickguy]

PCM of NC or 150tunes.com I've done business with both - reputable, and customer-service driven.

I don't think the Corvette solenoid would do anything for you, your transmission is electronically controlled

 

[dfarm]

Sorry, I meant a plug in tuner like diablo, superchips, ect.

 

[RacerX29]

The only faults I notice right now are an oil leak that appears to be from the right VC and the left side of the oil pan( it doesn't appear that these will be terrible to fix) there is a "service suspension soon" message in the gauge cluster, which I'm 99% sure is from not having the "active" struts on it anymore. And some of the electronic options inside aren't working.
Thanks in advance!

More than likely, the code for the "Service Suspension Soon" is because the previous owner removed the autoride shocks. They are electrical, and if they're not replaced with OEM shocks, the system will throw off an error. You can trick the computer by wiring in a resistor. I did this with my 2000 Suburban 2500 6.0, and haven't had a problem since. I'm running Bilstein 5100s, and I think the overall ride is better. I've leveled out the truck by adjusting the keys. The details for the resistors can be found here:

http://www.fullsizechevy.com/forum/...maintenance/291516-autoride-disconnect-2.html

Good luck with your build, I'm interested in how things turn out & which direction you decide to go.

 

[RacerX29]

The only faults I notice right now are an oil leak that appears to be from the right VC and the left side of the oil pan( it doesn't appear that these will be terrible to fix) there is a "service suspension soon" message in the gauge cluster, which I'm 99% sure is from not having the "active" struts on it anymore. And some of the electronic options inside aren't working.
Thanks in advance!

The error that you are seeing is likely due to the autoride shocks being removed. There are electronic hook-ups that go into a body control module, and if the previous owner simply removed the factory shocks without reprograming or otherwise fooling the system into the thinking the shocks are still there, you'll get a warning light on your dash.

Rather than buying the expensive OEM shocks, I swapped mine out for Bilstein 5100s, and spliced a resistor into place at each corner. So far, no issues. There's a write up on another forum (Full Size Chevy) started by a guy named Jacqson that I used to get the idea. The resistors you need are 3.9 Ohm 25 Watt Resistors; cut off the old plugs, spliced on quick connects to both wires (again at each corner), plug in the resistors, shrink wrap them up for protection, zip tied out of way. I've had them set up that way for a couple years with no issues.

Seeing as how I have the older brother (2000 Suburban 2500 LT 6.0 4wd) of your Suburban, I'm curious to see how your project evolves. Good luck!

 

[dfarm]

Kicking this thing back to the front, hopefully for a little help.

The oil leak that I mentioned earlier has gotten a bit worse. I replaced the gasket for the oil cooler adapter, and spent what seems like a few hours looking for the source of the leak.

It appears to be coming from between the heads and running down the bell housing, wetting mostly the right side of the engine and starter, but the left rear of the oil pan is wet also(where the oil filter screws on).

The back and top edges of the valve covers don't appear to be leaking, and I'm 90% sure the oil pressure sensor isn't leaking.

Is there anything else up there that has a track record of leaking oil? I'm hoping for ideas before I get too frustrated with it and pull the intake so I can see back there. Lol

Thanks in advance!

 

[lam396]

No help on the oil leak but if you haven't got a plug in tuner yet I would recommend not. Get a custom tune from Blackbear and he will be able to fix the suspension light and fix your shift points so that you also wont need the Corvette servo. I have a few mods to do to my Suburban first but I plan on having him tune it.

 

[plumber mike]

I've heard nothing but good about the blackbear tunes.

I don't have a specific spot to check for the oil leak, but they were known to have intake manifold gasket issues so pulling that might not be a bad idea....just a lot of work. The only other easy fix option I can think of is high mileage oil. It has an additive that causes seals to swell. Might be worth a shot if that's the only reason your tearing into it.

 

[dfarm]

Looking at some stuff online, it looks like the intake shouldn't have oil or coolant in it, but what about the aluminum valley pan, are they known to leak? If the back of that were to leak, it would be the correct spot.

 

[twodollars]

Your new burb should have a 4l80e in it, sharing about no components with a 4l60 or 700r4. I don't believe there's a corvette part that's going to do what your looking for.

 

[plumber mike]

Looking at some stuff online, it looks like the intake shouldn't have oil or coolant in it, but what about the aluminum valley pan, are they known to leak? If the back of that were to leak, it would be the correct spot.

I'm fairly certain the known intake leak pulls air rather than leaking oil, but it can cause confusion for your computer. I seem to remember it a problem for the 5.3....not sure of the 6.0. If you don't have any codes, it's likely not a problem. Head gasket or valve covers? Have you fully degreased the engine to catch that first drip in the act, straight from the source?

Good luck and keep us posted.

 

[superbuickguy]

A common problem with the intake is the crack where the egr cross over is. the only repair is replacement (though, as far as parts go, isn't that expensive). Do keep an eye on this issue, if it cracks, it'll also crack the water crossover and fill the motor with coolant (extreme cases).

the 6.0 is a pretty bulletproof block - thus, anything I could say would be just guesses. You can put a photoreactive fluid in the oil, run the vehicle for awhile, then trace its source. there really isn't pressurized oil between the block and the head... and really, the only pressurized place for oil on the top of the motor is the oil sender. The oil itself gets to the top of the motor through the lifts, up the push rods and out the rockers. The traditional place for it to leak is the valve cover gasket....

 

[dfarm]

I had the idea of using dye in the oil, unfortunately, someone before me did too. Lol. I can see the back of the heads are dry, and I can see the sides of the VC don't appear to be leaking. It looks like its coming between the heads.