2006 Suburban 2500

[imi4tth3w]

Well, i made a bit of an unfortunate discovery today.

I found out why the fuel gauge isn't working...

Took some time to look under the truck today to see if I could troubleshoot the fuel gauge issue. I ended up finding some extra hoses and some hacked up plugs and duct tape.. i also read that these 2500 burbs have dual fuel tanks but i only saw one...

i only saw one fuel tank.. the auxillary fuel tank that is supposed to be above the spare tire is literally non existent lol.

Google tells me that the replacement tank part number is 23306963 and runs about $600 + shipping + whatever else i need to install this thing.... fuel pump/sender, fuel tank straps, any hoses or bolts to go along with that, etc... could be worse i guess.

Probably end up replacing both fuel senders while i'm down there mucking around with things. Guessing this will be a $1500 repair.

But i will say i'm just glad i never had any issues in my 500 mile drive home from where i bought it. I will definitely not be driving this thing until i get this fixed. Duct tape fuel lines is just a giant safety issue.


2nd fuel tank is MIA



The filler hose has a Y in it, so both tanks get filled at the same time when filling up. The pipe that supposed to go to the 2nd fuel tank is duck taped.... -_-



2nd fuel sender plug is taped up... Definitely explains the CEL error i was getting



No tank from the other side.




some hoses above the MIA spare tire


So it looks like this weekend i'll be dropping the tank. I was actually already trying to drain the fuel tank anyways and according to hp tuners it's got about 6-7 gallons left in the primary tank so it shouldn't be too bad. Just want to figure out the routing of all the hoses, what's missing, and what needs to be replaced. go from there.

I did win an auction on a set of cats for this thing which should be here next week. So it's looking like fuel tank teardown this weekend, exhaust replacement next weekend, then fuel tank replacement/fixes the following weekend assuming i can get all the parts in?

That's all for now

 

[imi4tth3w]

Excellent work!

I love the 2500 Suburbans. Looked at a 2013 2500 Suburban before I bought my 2016 Tahoe. They are days I think I should have bought it. Especially when I drive the pot holed streets in NYC and New Jersey as I am up there often. With that said I am very content with my Hoe.

I generally do not keep up with this section due to time restraints. But since I started from the beginning on this thread will do my best to keep up.

Thanks for the comment!

The 1500 Tahoes and Suburbans really do make great daily drivers. My daily is an 08 Tahoe and i will likely continue to daily it and leave the suburban for overlanding/weekend duties.

I'm still partial to the GMT800s though. The nnbs style trucks just don't quite do it for me. But i will admit i inherited the 08 Tahoe so i can't complain there.

 

[imi4tth3w]

Quick update:
Made a fun 500+ mile drive today to pick up this!


It's a little dirty, but this is the replacement auxiliary fuel tank! (the one that came in my truck was lovingly "deleted" by the previous owner for unknown reasons...)

Tried to find a new one, but it was basically unavailable from GM and on "backorder". Seeing as I highly doubt GM is going to be manufacturing more of these anytime soon (if ever?), i ended up picking this one up from a junk yard for 1/10th the cost.

There's a couple more pieces I need for this puzzle (sending unit, straps, and the big one... ????) so it'll be a minute before i get it under the truck. Definitely glad to have this hard to find part waiting patiently in the garage.

Here's a couple more pics



Still not sure exactly what the fuel capacity is of this tank. Chevy says 15 gallons but most online says its 11. I know for certain the total fuel capacity of this truck is just over 38 gallons and I've heard the main tanks are 27 gallons. Simple math says the auxiliary tank is about 11 gallons.

Here's some diagrams I've found.

Auxiliary tank is item #2 (GM PN 2330696)


I believe i'll probably need the following:
Fuel Tank Straps #4 (GM 15757605)
Fuel Tank Strap Bolts (not shown) (GM 11515767)

I'm having trouble finding diagrams of the fuel lines for this dual tank system so i'm really hoping i have everything i need. worse case some weird hose or something is missing and there's no way for me to get a new one which would really suck. Although i supposed i could always use aftermarket parts to make it work.

 

[imi4tth3w]

more updates!

Got the aux fuel tank cleaned up and a new fuel sending unit in.




There's two connections inside the fuel tank


The small one is unfortunately missing a small fitting. It came with some extra hoses but it looks like this blue clip is 3/8 and i need a 5/16. Amazon should have me a clip sometime tomorrow


I also found a great diagram of the hoses for the aux tank so it should hopefully be smooth sailing to install everything.


I also picked up a new sending unit for the main tank so while i wait on this clip i should hopefully get the main sending unit replaced tomorrow.

If there's any time left over i've got some surprises for the exhaust system..

 

[Bill 1960]

I really appreciate your sharing all this. Although my wallet may have a different opinion. I’ve been thinking ahead to what project I want to play with this winter. Maybe some HD parts grafted into the Tahoe; or maybe sell it and start fresh with a 2500 Burb.

A 2500 Tahoe would be my ideal vehicle. Just have to decide if I want to build a Frankenstein or go with a longer vehicle.

Looking forward to seeing your build progress.

 

[imi4tth3w]

So this weekend was certainly... interesting..

to start, i went underneath the vehicle to remove some duct tape. Found this in the aux tank fuel filler hose






I'm assuming the previous owner was using all this to block off the hose... just seemed really random.. But it looks like i'll need a new hose. Gotta call the dealership to figure out the part number as the online search tools are all ******* up for these trucks (doesn't even show this has dual tanks?)

Anyways since that hang up there i went ahead and played with some exhaust goodies...

 

[imi4tth3w]

I went ahead and splurged on some nice JBA ceramic coated short tube headers! Passenger side original exhaust manifold has a stripped bolt where it bolts to the cats so i figured might as well.




I had previously removed the passenger size exhaust manifold and found that the missing bolts were just not there (instead of being broken off in the head) and assumed the driver side would be the same story.... not the case.

Drive side exhaust manifold has two broken off bolts deep in the head (front and back side bolts of course). Plan is to get the dorman exhaust manifold support brackets for now as i'll need to pull the engine to properly drill and remove the broken off studs. Although i might pull the engine sooner than later as the rear main seal looks like its been leaking like crazy. Hard to tell right now with all the grease still coating everything down there. More work with the power washer in the near future..

So other than the broken bolts in the head, the header install went very easily.

Next was to bolt in my new catalytic converters. All my research got me the part numbers of 10395213 and 10395214. Well it looks like these are the part numbers for the 1500 trucks that came with the 6.0 and not the 2500..... Its like they ALMOST fit but there's a couple strange differences. The driver side 10395214 cat had 2.5" pipe instead of 2.75". The passenger side was 2.75" but the exhaust hanger was completely off.




So after a call to the dealership so they can look up my vin number, the actual part numbers are 15793201 & 15793200. They quoted me $1200 + $400 core charge.. each.. and the cores have to be 100% unaltered or they won't accept them... yikes.. and i still need to figure out how to unload these wrong cats i got. I was really excited when i saw the pair for $900 on ebay but it was too good to be true.

But i did at least get some validation that the cats in this thing were done. If you knock on the original cats they seem hollow, but had no signs of being modified. Not sure if the catalyst material inside them just deteriorates over time. The new cats i got were nice and solid when you knock on them.

Anyways not sure what i'm going to do about the cats for now. It also exposed just how bad a job the exhaust shop did. You can see they didn't even seal the weld around the whole exhaust (just visible in the above pictures).

Since both the fuel system and exhaust system are on hold, i figured it was time to move on to stripping the interior for deep cleaning..

 

[imi4tth3w]

Made some progress stripping out the back of this thing. There is thick dirt EVERYWHERE.



Its going to be a real nightmare tearing down the rear AC for cleaning. But, i'll be happy i did with how dirty this thing is..

Also, for those who got stumped like me removing the passenger side 2nd row seat, it can slide forward!

This is the bolt i could not figure out how to remove


I then realize this mechanism here allows this seat to slide forward. This was only found on the passenger side and this is presumably to allow the seat to slide forward and load passengers into the 3rd row.

Of course my mechanism was also broken, so i had to manually release the "claws" in order to allow the rail to slide forward for seat removal.


I superglued the piece back together but it still doesn't seem to be operating correctly. Going to leave it as is for now and worry about it once i get things put back together.

That's about as far as i got this weekend. The biggest issue with tearing down the interior is finding a place to put all the parts while its disassembled for cleaning... The things i would do for a nice big shop to work in lol.

That's it for this week.

 

[Tonyv__]

Never knew the 2500 burbs had dual tanks. Only truck I knew of with that feature was really old f150s

while I’m learning. Do them beef up the rear suspension with leaf springs on the 2500s. Vs coils

Edit. I answered my own question. I can see leafs in one of the pictures. Nice truck have fun building it up

 

[Tonyrodz]

Can you have the new cats welded to the old pipes? You can sell the old cats to a scrap yard--for good money.