Bought my first Tahoe today. Need advice on what to watch out for and perhaps replace.

[04Z71w]

Hello,

I bout my first Tahoe today, a 2004 z71 with 275k miles. Bought it for a pretty good price and in above average condition for how old it is.
I'm a sports car person but decided I wanted a Tahoe for the occasional camping trips and what not.
Not knowing that much about them I'm just wanting some advice on what to look out for at 275k miles. The transfer case was replaced 6 months ago ( verified ) along with the rear main seal and a rebuilt transmission but not completely rebuilt just some parts or 780 worth of it.

Only issues I have with it are one or both the catalytic converters are going bad as its running super rich and reeks of unspent gas through the exhaust.
Steering is a bit loose, brakes are super spongy and the temp gauge hovers around 200 to 220 degrees, depends on the load but doesn't actually over heat just goes a little past 210 degrees then back own for a bit.

Saying that what should I watch out or possibly slowly replace? My plans are to replace the radiator, upgrade to better cooling fans as the ones on there now are super noisy. like loud as all get it out like a wheezy cough Look into buying a complete suspension kit and replace the front as well as with the steering components. I already have new coolant hoses and belts should I need.

Biggest things are the A/C front and Rear works like a charm which is needed in North Texas this time of year.
Any advice or preferred parts to use would be helpful. Right now planning no performance mods until normal stuff gets sorted.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

Replace all fluids that you do not know the last time that they were replaced. I would not recommend any suspension lifts with that many miles on the truck, unless you are going to replace the entire suspension in the process (which it appears that you may).

Good brakes are extremely important on these heavy beasts, so get the brakes replaced.

Regarding parts and their sources, I recommend that you use genuine GM or ACDelco replacement parts, whenever you can. The best prices for these genuine parts are RockAuto.com (5% discount for being a member here and using the promo code buried on this site), GMPartsGiant.com, and GMPartsDirect.com.

Other folks on this Forum will chime in with their thoughts and perspectives.

 

[Bill 1960]

Welcome. I would not condemn the cats before some analysis using a good scan tool that can view live data. Running rich could be O2 sensors, fuel injectors, or even a temperature sensor.

 

[Doubeleive]

First thing I would address is the brakes, you could maybe just need to flush and bleed them real good but inspect and if need be do pads and rotors at the same time
I would then move on to the cooling system, temp should be rock solid under normal conditions and should not fluctuate at all, being high mileage and unless you have evidence that it has been replaced in the last 5 years I would just replace the radiator and flush everything out real well, use some radiator flush first with just water and run it a couple days, drain and refill with water a couple times afterwards then use 50/50 coolant/water mix for the final fill. this should resolve the temp fluctuation if not then you need to move on to the thermostat and water pump.
you may want to invest in a good scanner like a tech2 it's what the dealers use, you could use that to see what is going on with rich mixture and go from there. cat's are pretty pricey right now due to covid and production being slow. so I would try to stretch that need out until the prices get better again. just for reference cat prices are double what they were pre-covid.

 

[OR VietVet]

Safety first=brakes and steering components. Then the slight running warm and the new fans when do the radiator and also the thermostat. Like @Bill 1960 said, the cats may be needed but something caused that problem/smell. Full inspection of that system is needed but at that mileage and age, will likely need O2 sensors and go from there.

 

[04Z71w]

Thanks for all the info!

I did manage to get out there and inspect the brakes. Rotors are fairly worn down and the pads are I would say 80% gone so I'm going to update them with better than OE parts. What's a good upgrade for rotors and pads? When I do those it'll get a full flush and bleed.
The suspension looks to be original and a bit worn so I'm going to have to do a complete front end suspension/steering tune up on it.
The cooling system is getting replaced as far as the radiator/fan/fan clutch and hoses. The ac works real well however the ac condenser looks real bad so I might change that out. I'm going to have a GM mechanic check out the steering this weekend that's beyond me and since it's a major component it's better a pro diagnose it.

It actually has an exhaust leak at the exhaust manifold and where it meets the y pipe. I'm guess that's why the CEL keeps popping on and off. Plus I can hear it ticking and hissing.

I'm not a lifted truck person so it'll probably remain stock height with better suspension or I may lower it a little for an even clean look but not lowered to the ground.

But yes this weekend I am going through all the standard protocol of restoring a car and start with the brakes/cooling/suspension and emissions parts and replace what needs to be replaced for normal operating conditions first. Thanks for the advice. Only picture I have of it right now is attached.

I have to say I am by no means a fan of chevy but love the Tahoe's so damn cool.

 

[OR VietVet]

The exhaust manifold leaks are likely from broken bolts at the ends of manifolds. Dorman makes special clamps to fix that instead of drilling out and tapping and keeps from pulling head(s).

I don't think your rig has a fan clutch, should have electric fans, unless I am wrong. I do see a fan clutch listed at RA but my 05 Z71 has electric fans. Plus I had seen another thread about an 04 Tahoe that talked about electric fans. Maybe they had done a conversion.

If you want to really set up that suspension and have a better feel, use OE parts and install front and rear Hellwig sway bar kits.

 

[Tonyrodz]

If you wanted a little better front brake upgrade you can use rotors and calipers from 07-14 Tahoe/Yukon/Suburban. They have bigger rotors and calipers, and it's all oem. Also be a good idea to get some steel braided front brake hoses.

 

[OR VietVet]

If you wanted a little better front brake upgrade you can use rotors and calipers from 07-14 Tahoe/Yukon/Suburban. They have bigger rotors and calipers, and it's all oem. Also be a good idea to get some steel braided front brake hoses.

@Tonyrodz, don't you have to go to a bigger 17" wheel for those bigger rotors and calipers?

 

[04Z71w]

The exhaust manifold leaks are likely from broken bolts at the ends of manifolds. Dorman makes special clamps to fix that instead of drilling out and tapping and keeps from pulling head(s).

I don't think your rig has a fan clutch, should have electric fans, unless I am wrong. I do see a fan clutch listed at RA but my 05 Z71 has electric fans. Plus I had seen another thread about an 04 Tahoe that talked about electric fans. Maybe they had done a conversion.

If you want to really set up that suspension and have a better feel, use OE parts and install front and rear Hellwig sway bar kits.

It has a fan/clutch I believe in 05 is when they started using efans. I saw various youtube videos of people using 05 and up efan conversions on 04 and down Tahoe's/Silverado's. It's probably some thing I'll do in the future. I think a new fan and clutch will work just fine for right now. It's just so noisy ...more than it should be. This one video explained the conversion real well and how and how to program the Efan to run of the PCM. Looked fairly straight forward.

About to start cruising the ol internet for the steering/suspension parts...I should be working but F it one of the joys of working from home.

I'll def look into the dorman clamps though. That's a huge help right there.