Head Gasket or Swap

[AWOLASAP]

I have a 2004 Tahoe LT 5.3 FFV with 205k miles. About 8 months ago a tick started, and through a busy work schedule finally eliminated just about everything but the head gaskets. I confirmed this with a test from Blackstone that says I have signs of coolant in the oil.

My question is, is it a good idea to swap the head gasket (I'd do the work myself) or should I just swap the engine? I assume the issue stems from about 14 months ago I had a coolant line (firewall t-connector) crack off on an offroad trail. I stopped my car pretty quick but I'd assume it left damage. Would this mean head warpage and more stuff to fix than just a head gasket? I've also head of valve jobs needing to be done and some other stuff, this is the deepest I would be in an engine to date.

 

[OR VietVet]

When you say swap, do you mean a reman engine or a used engine. Used means lots of unknowns. Less expensive but unknowns. Reman means more expense and lots of work. Either way, if you have not been this deep in any engine, be prepared to find unknowns, no matter which way the fix is decided.

Do you love the Tahoe and want to keep it for long enough to get your money back out of it? Decisions to be made.

 

[West 1]

I have had many of these engines apart and the pistons and cylinder walls show very little wear even at 200,000 miles. My concern would be the heads, if you are repairing I would at least have the heads refreshed, checked for cracks, surfaced, new valve stem seals. After overheat these heads are known to drop a valve seat which lets the valve hit a piston and the engine would be toast so not a bad idea to get new valve seats. Heads alone may be $6-700 for this repair. Head Set for the rebuild maybe an another $100, new head bolts and exhaust bolts another $75, plus all the items to check or replace while in there. Water Pump, Thermostat, Oil pressure sender, Radiator and Heater Hoses maybe $250 more. It all adds up but should buy you several more years of use if you want to go that route.

Check with local machine shops in advance, they may say it will take 3-4 days or 3 weeks to fit your heads into their schedule. Rebuilt heads can be purchased in advance from some sources, might be for about the same price as rebuilding yours and eliminate the time delay.

Final thought, these are not easy engines to repair, it takes a lot of time and good tools to do this job properly. Plan to remove some broken bolts out of the heads once the manifolds come off and the Head Bolts absolutely need to be replaced and there is a multiple step process to torquing your new head bolts or you will not succeed. It can be done just do not expect easy and follow the book.

 

[AWOLASAP]

When you say swap, do you mean a reman engine or a used engine. Used means lots of unknowns. Less expensive but unknowns. Reman means more expense and lots of work. Either way, if you have not been this deep in any engine, be prepared to find unknowns, no matter which way the fix is decided.

Do you love the Tahoe and want to keep it for long enough to get your money back out of it? Decisions to be made.

I don't know all the terms but I was thinking a remann or crate if I did swap. I can't swallow putting a used engine with a bunch of unknowns.

The deepest I've been is intake manifold and swapping rocker arms so I expect it to be a long weekend if I do either since its my daily driver. The car has served me well the fast few years, I've put a good bit of money into it, makes it hard to swallow selling it for cheap to buy something more expensive.

 

[strutaeng]

If you watch any YT videos, they make it sound like anyone with an engine hoist and basic tools can overhaul an LS engines in their backyard...which is kinda true, but I agree with @West 1 . It takes time, effort and elbow grease to rebuild an engine, any engine. Money and a space to work as well. Then vehicle will be down until you complete the work, if this is your only vehicle.

But if you do it yourself, you can save thousands of dollars. Last year I rebuilt the LQ4 on my 06 Suburban due to an intermittent lifter tick. Engine had 265k and the internals were in shockingly good condition. Just replaced bearings, piston rings, and gaskets. Not uncommon to open an LS engine up with 300k and only have marginal wear. I got the heads remachined/cleaned up and that was $350. Overall I spent like $1300 plus $200 for some tools I didn't already have, and that included a slightly mild camshaft. https://www.tahoeyukonforum.com/threads/tty-head-bolts-with-engine-in-vehicle.147231/page-3

An aftermarket 5.3 longblock is around $3800-$5000+ last I checked depending on OEM vs modified somewhat.

And you still have to swap the engine or pay someone to do it. Probably another $1500 if I had to guess? IDK on that, there's a lot of regional variations on labor rates across the country...

The good news is that just about anything on these trucks is relatively easy to work on and super common, so that should keep the cost down if you have a shop do the work.

 

[Marky Dissod]

About 8 months ago a tick started, and through a busy work schedule finally eliminated just about everything but the head gaskets.
I confirmed this with a test from Blackstone that says I have signs of coolant in the oil.

After 8 months of driving around with coolant in your oil, swap the engine.

 

[OR VietVet]

Plan on more than one weekend if swapping the engine and get some help.

 

[Joseph Garcia]

As @OR VietVet stated above, this is NOT a weekend project. If you believe this, you are deluding yourself, and you will end up most unhappy.

If this is your daily driver, then make arrangements for another vehicle during this project.

 

[rockola1971]

Stick a 6.0L in there!

 

[AWOLASAP]

Stick a 6.0L in there!

Is it much work to do so? I've read that it'll require an ecu tune and wiring harness, but that its a bolt up replacement even fitting the 4l60e.

 

[rockola1971]

Is it much work to do so? I've read that it'll require an ecu tune and wiring harness, but that its a bolt up replacement even fitting the 4l60e.

You can get a PCM tune OR just stick a PCM from 6.0L model in your vehicle. You can change any wires around at the plugs of the PCM so you wont have to replace main wiring harnesses. 4.8, 5.3, 6.0 all have the same bellhousing.

 

[Marky Dissod]

Is it much work to do so? I've read that it'll require an ecu tune and wiring harness, but that it's a bolt up replacement even fitting the 4l60e.

It will not require a wiring harness; it will require a tune, it bolts up like your old engine did, it's TOTALLY worth it.