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.

 

[OR VietVet]

I had to use 3 of the clamps and they work flawlessly.

 

[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.

You're right...upon inspection this morning 2 bolts are broken. One on the passenger side front and the other drivers side rear of which looks like a pain to get to. I went a head and bought the dorman exhaust clamps for all of them.
Flushed the coolant system and replaced the hoses and that seem to hold the temp better although it still slightly varies but not as bad as it did before. Bought a new radiator so when that get in I'm going to change that out a long the fan/clutch and thermostat for good measure. Then off to starting on the steering and suspension.

For now I just need this thing to pass inspection so I can get the title transferred over to me. Yea even though it past 9 months ago, In Texas, it has to pass within 180 days of transferring the title. So I'm just going to fix up the exhaust leak with the clamps for now and worry about a permanent fix later. Might go short tube headers. Even though LTs are better, I'm not after the most horsepower more of a mild cruiser. Plus I can get the bbk shorties for 1/2 off.

 

[OR VietVet]

Depending on the exhaust manifold bolts location, the head has to come off for the work. If inclined, may be the right time for new/reman heads.

When you do the radiator, the hose to the reservoir bottle needs a slight restriction for the temps to be in the right window. Several threads here about that. Can use a hose clamp on it and pinch slightly for the restriction. One member here got very creative and designed a restriction for the nipple on the radiator. Again, those threads are full of info.

I am confident that the exhaust clamps can last and do the job as long as you want them to.

 

[04Z71w]

reman heads is what I was actually looking at this morning. Few shops in my area have pretty good prices.
Another discovery is it looks like the water pump weep hole is leaking coolant so I have added that to my parts list run today.
Should be an interesting weekend changing out pretty much the whole cooling system.

The drivers side rear exhaust manifold bolt looks to be the hard since the hole is behind the block almost against the firewall. I think I can rig some thing up to get in there and tighten down the clamp.

 

[OR VietVet]

The clamps are different part numbers depending on the location of d/s or p/s front or rear. They are designed to allow for easy enough access to install. Don't settle for heads that are just the cheapest. Do the research and ask here for suggestions. Too much work to settle for inferior heads.

 

[04Z71w]

The clamps are different part numbers depending on the location of d/s or p/s front or rear. They are designed to allow for easy enough access to install. Don't settle for heads that are just the cheapest. Do the research and ask here for suggestions. Too much work to settle for inferior heads.

Of course not that goes with old verbiage ''get what you pay for ''. I'll probably get a set done where I got the heads sitting on my 68 mustang done at which has a 390. Little pricey but damn good work was just comparing average prices around my area. There are a good amount of LS engine builders here that I think I'll be fine.

 

[chevylade]

You should check all of the brake lines carefully as it’s not unusual for those to fail. I personally would go ahead and replace all of them. As for replacement brakes, I use the PowerStop Z36 kit on my ‘03 Escalade. They feel stronger than oem and don’t put out a lot of dust. I bought replacement calipers from NAPA that have a lifetime guarantee. I also replaced my front suspension with the higher end Moog parts. I sourced my parts from Amazon, Rockauto, and Napa.

 

[04Z71w]

You should check all of the brake lines carefully as it’s not unusual for those to fail. I personally would go ahead and replace all of them. As for replacement brakes, I use the PowerStop Z36 kit on my ‘03 Escalade. They feel stronger than oem and don’t put out a lot of dust. I bought replacement calipers from NAPA that have a lifetime guarantee. I also replaced my front suspension with the higher end Moog parts. I sourced my parts from Amazon, Rockauto, and Napa.

Thanks!

I did see Moog parts on amazon and was going to ask about those as well as the powerstop rotors. Looks like the suspension and steering components are worn out and just need a good over hual. Mechanic said the steering rack was ok but not a bad idea to change that out to if I was to go and replace everything else. I also got Bilstein B6 shocks on the list. This weekend the water pump, belt. fan clutch, hoses and radiator are being replaced and I might go ahead and do the AC condenser.

I'll def buy new brake lines through....I didn't even think about that.

 

[Tonyrodz]

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

Yes. Need to be at least 17's.

 

[Teamiez]

Thanks!

I did see Moog parts on amazon and was going to ask about those as well as the powerstop rotors. Looks like the suspension and steering components are worn out and just need a good over hual. Mechanic said the steering rack was ok but not a bad idea to change that out to if I was to go and replace everything else. I also got Bilstein B6 shocks on the list. This weekend the water pump, belt. fan clutch, hoses and radiator are being replaced and I might go ahead and do the AC condenser.

I'll def buy new brake lines through....I didn't even think about that.

I used the higher end moog steering / suspension parts on my tahoe and have no complaints. They have grease zerks and went 37,000 miles no problems so far. Your Tahoe should have a steering gear box, not a rack and pinion. If the gear box is good at that mileage consider your self lucky and keep it! Remanufactured ones that don’t have slop are hard to find! I learned that the hard way by replacing it anyways with everything else like you mentioned haha