Question for the LS gurus. Blown head gasket LQ4

[mesquito_creek]

I am the original owner of a 2005 6.0L LQ4 chevy 2500. It has 190,000 miles an just blew a driver side head gasket on the rear side of head. Still runs an drives fine but is leaking coolant in a bad way. What is the right way to repair it?

1) just replace one head gasket and send the old head out to be inspected for any issues with warping etc...
2) replace both head gaskets and send out both heads.
3) replace both head gaskets and buy 2 new heads.

I am going to do the work myself in my garage/shop. This is an extra truck that only gets used a couple thousand miles a year for camping/fishing and towing some stuff around occasionally. It is not a daily driver.

 

[Cole Trickle]

New factory head gaskets (i think ls9 work)

Go through both heads add some springs,new lifters and upgrade the cam/oil pump while you have it apart.

@Bigbore500r can shed some lights on what parts to use.

 

[Backlash]

Pull the motor, pay $2500 for a low-mile drop-in motor and work on that original motor later on down the road. Rebuild it with all new components at your leisure. When the drop-in motor gives up the ghost in 5-10 years, you'll have a replacement motor ready to go with all new parts. Rinse and repeat!

 

[BigRedBryan]

I am the original owner of a 2005 6.0L LQ4 chevy 2500. It has 190,000 miles an just blew a driver side head gasket on the rear side of head. Still runs an drives fine but is leaking coolant in a bad way. What is the right way to repair it?

1) just replace one head gasket and send the old head out to be inspected for any issues with warping etc...
2) replace both head gaskets and send out both heads.
3) replace both head gaskets and buy 2 new heads.

I am going to do the work myself in my garage/shop. This is an extra truck that only gets used a couple thousand miles a year for camping/fishing and towing some stuff around occasionally. It is not a daily driver.

Do both heads at the same time, fresh valve job done, truck will last you another 200k, why do extra stuff if everything else is good, especially if it's just a spare vehicle?

 

[monkeyswrench]

TTY head bolts, so be ready for that, and factory MLS gaskets. The best thing is, you can grab the head with one hand. Sucks balls with a 2000 or early 01...iron LS heads!

 

[mesquito_creek]

Do both heads at the same time, fresh valve job done, truck will last you another 200k, why do extra stuff if everything else is good, especially if it's just a spare vehicle?

Jegs sells complete ATK reman heads for $440 with valves and springs… doubt I can get them done locally for less. Do I just reuse the bolt on rocker assembly?

 

[BigRedBryan]

Jegs sells complete ATK reman heads for $440 with valves and springs… doubt I can get them done locally for less. Do I just reuse the bolt on rocker assembly?

I'd personally have the original equipment (heads) rebuilt, as stated above replace all the head bolts since they are torque to yield. Yeah rockers should be able to re-use. At least I always do.

 

[rrrr]

I'd personally have the original equipment (heads) rebuilt, as stated above replace all the head bolts since they are torque to yield. Yeah rockers should be able to re-use. At least I always do.

Why? ATK rebuilds thousands of the heads every year and warranties them. What's the advantage of having an unknown automotive machine shop using unknown parts or reusing old parts doing the work?

 

[fast99]

We have always used a local rebuilder for head work. Why spend money for shipping, returning cores may get expensive.

Our shop has purchased a couple complete engines from ATK when not available locally, they ran fine.

From the ATK warranty. Good idea to read all of it.

DIY installations, DIY repairs, repairs performed by unlicensed repair facilities, or repairs made to units not originally installed by a Licensed Automotive Repair Facility do not qualify for labor reimbursements. Warranty repairs must be completed by Licensed Automotive Repair Facilities.

 

[Canuck 1]

How to fix an ls

 

[lbhsbz]

Jegs sells complete ATK reman heads for $440 with valves and springs… doubt I can get them done locally for less. Do I just reuse the bolt on rocker assembly?

I wouldn't buy anything that ATK touched.

 

[lbhsbz]

Why? ATK rebuilds thousands of the heads every year and warranties them. What's the advantage of having an unknown automotive machine shop using unknown parts or reusing old parts doing the work?

Because ATK is shit, always has been. Their parent company (LKQ) is in the junkyard business

 

[BigRedBryan]

Because ATK is shit, always has been. Their parent company (LKQ) is in the junkyard business

Couldn't of said it better myself, and I also like supporting my local machine shop along with keeping my stock GM heads. I avoid putting rebuilt Chinese shit on anything as much as possible.

 

[mesquito_creek]

I can run the heads over to local machine shop who I have used in the past. They can check for cracks and resurface for about 200 a pair or add valves and spring for another 200… so right in line with ATK, but local! Honestly the motor runs perfect even with leaking gasket, probably just check for cracks/resurface and bolt it all back together with new TTY bolts. The biggest issue I have is it doesn’t get used enough….

 

[Shlbyntro]

cylinder heads intl out of Flower Mound, TX

 

[LargeOrangeFont]

Are you sure this is the head gasket? Any evidence of coolant in the cylinder or in the oil?

2 options -

Buy a pullout and roll the dice- probably a good chance it will be fine.

Other option buy a set of heads and have them gone through if you are in a time crunch, or pull yours and have them gone through.


Gotchas - exhaust manifold bolts. Use penetrating lube on them, maybe even a little heat. If the heads are coming off it is not a huge deal if they break, just more money for the machine shop to fix.

Use new MLS head gaskets
Use a fresh set of the later style LS head bolts - Had good luck with Fel-Pro for OE replacements.
Put in new lifter trays.
LS6 springs are cheap
Use new exhaust manifold bolts.

If you have the timing cover off you could do a new oil pump. But you don’t have to pull the timing cover off to do the job.

 

[77charger]

Personally in your case I’d pull both heads have rebuilt reassemble call it good.

 

[BigRedBryan]

TTY head bolts, so be ready for that, and factory MLS gaskets. The best thing is, you can grab the head with one hand. Sucks balls with a 2000 or early 01...iron LS heads!

That's interesting, always thought they were aluminum, I just worked on a 99 5.3 gmc today and it has aluminum heads, original engine too.

 

[LargeOrangeFont]

That's interesting, always thought they were aluminum, I just worked on a 99 5.3 gmc today and it has aluminum heads, original engine too.

I believe it was just the early 6.0 that had iron heads and the weird crank.

 

[monkeyswrench]

That's interesting, always thought they were aluminum, I just worked on a 99 5.3 gmc today and it has aluminum heads, original engine too.

It may be a 6.0 only thing? The only 2 I have seen were both 2500's and 6.0. The first one was an oil soaked pig, dirty from dirt roads. Not paying attention, buzzed it apart, damn near lost a nut when I went to grab it

 

[mesquito_creek]

@LargeOrangeFont Is there anything else in the rear driver side that can leak? I degreased and power washed everything and the leak starts quick right in that area.

See if this video does anything but make you sea sick

 

[LargeOrangeFont]

@LargeOrangeFont Is there anything else in the rear driver side that can leak? I degreased and power washed everything and the leak starts quick right in that area.

See if this video does anything but make you sea sick
View attachment 1172576

There is a freeze plug there. And it looks like it has a trail below it..

Could still be the head gasket, hard to tell, and the result may still be the same if it is the freeze plug though.

 

[mesquito_creek]

I will drain the oil once the coolant stops running over the oil pan… either way I will have to remove a lot of stuff to get to the back of the motor

 

[mesquito_creek]

Besides an AC unit and typical stuff like water pumps/radiator…. First major repair on a 17 year old born and raised AZ truck, pushing 200k. I still like keeping it around!

 

[BigRedBryan]

Check your plastic connectors that go to the heater core, they fatigue with age. If they've never been replaced now is a good time. Only use dealer parts for them tho.

 

[mesquito_creek]

Check your plastic connectors that go to the heater core, they fatigue with age. If they've never been replaced now is a good time. Only use dealer parts for them tho.

I am intimately familiar with those and carry a spare!

 

[monkeyswrench]

What about the o-ring for the steam crossover? That just looks like a lot for a head gasket.

 

[LargeOrangeFont]

What about the o-ring for the steam crossover? That just looks like a lot for a head gasket.

Do those older trucks have the 4 corner steam system?

 

[Big B Hova]

Best option is 408 stroker with ls3 heads and twin turbskies.

 

[Shlbyntro]

better just drop a 502 with a blower on it in there and call it good

 

[mesquito_creek]

What about the o-ring for the steam crossover? That just looks like a lot for a head gasket.

I will drain the oil in the morning and if it’s clean then I will be suspect of my head gasket theory. Then I will do compression. It’s running normal and the coolant is clean that I am seeing. It looks like the steam crossover requires me to remove the intake?

 

[braindead]

Check your plastic connectors that go to the heater core, they fatigue with age. If they've never been replaced now is a good time. Only use dealer parts for them tho.

almost lost my engine in traffic the day I bought my first boat because of that shitty design, it was also a 6.0L.

now I use these, even got ‘em for SUVs. They also make other replacement parts around the vehicle such as the gears in the electric mirrors and power liftgate that strip out.

Billet Heater Core Outlets

Welcome to Gruven Parts, your online home for custom auto parts.

www.gruvenparts.com

 

[HALLETT BOY]

I’ve installed my share of ATK products over the years , their support and warranty leaves a lot to be desired .

 

[LargeOrangeFont]

I will drain the oil in the morning and if it’s clean then I will be suspect of my head gasket theory. Then I will do compression. It’s running normal and the coolant is clean that I am seeing. It looks like the steam crossover requires me to remove the intake?

Correct. If that is the issue it will be an easy fix.

 

[Ace in the Hole]

Best option is 408 stroker with ls3 heads and twin turbskies.

Shit just go junkyard Lq9 they will hold a lot of boost before they give up the ghost lol

 

[monkeyswrench]

I will drain the oil in the morning and if it’s clean then I will be suspect of my head gasket theory. Then I will do compression. It’s running normal and the coolant is clean that I am seeing. It looks like the steam crossover requires me to remove the intake?

Mirror and a couple pillows...the pillows are gut/crotch protectors to lay over the core support and intake. The big dentist mirror on a stick and a flashlight, or stick your phone back there and take a bunch of pics.

The older LQ9's I think had the X pattern crossover still. I have seen them crack, but always up front when someone was stupid. Each corner has a machined block with a bolt hole. The bottom sticks down maybe a 1/4 inch. I've seen both a rubberized aluminum gasket, and an O-ring. Pretty sure the aluminum one is factory, but don't know for sure. I think it's an 8mm bolt? You can do them with the manifold on, but it's a lot easier to pop the intake off. All I do with them is string them up and back a bit with bungee cords. Usually for knock sensors.

 

[mesquito_creek]

Mirror and a couple pillows...the pillows are gut/crotch protectors to lay over the core support and intake. The big dentist mirror on a stick and a flashlight, or stick your phone back there and take a bunch of pics.

The older LQ9's I think had the X pattern crossover still. I have seen them crack, but always up front when someone was stupid. Each corner has a machined block with a bolt hole. The bottom sticks down maybe a 1/4 inch. I've seen both a rubberized aluminum gasket, and an O-ring. Pretty sure the aluminum one is factory, but don't know for sure. I think it's an 8mm bolt? You can do them with the manifold on, but it's a lot easier to pop the intake off. All I do with them is string them up and back a bit with bungee cords. Usually for knock sensors.

After watching a few videos I think you got this correct in terms of what my problem is! I think I will just remove the intake (tie it up out of the way) The extra work to remove the intake is a fraction of what it could be if it’s head gasket. I can take my time and work my way through it!

 

[lbhsbz]

I will drain the oil once the coolant stops running over the oil pan… either way I will have to remove a lot of stuff to get to the back of the motor

Why,....just pull out the dipstick. No sense wasting 6 quarts of oil at the price of oil these days.

You have an external leak. External headgasket leaks DO NOT follow the typical protocol for failed headgaskets....you very well might not have combustion pressure leaking out of the cylinder or coolant leaking into the cylinder. You may not have coolant mixing with oil....actually, you probably won't.

If the dipstick doesn't show milkshake and the oil cap looks as expected (minor milkshake is expected with infrequent use and short trips)...then I'd proceed in the following manner:

Dry/Clean everything off

Get some dye...here's a kit https://www.amazon.com/FJC-4972-Fluorescent-Leak-Detection/dp/B008QEYTZ4/ref=sr_1_12?gclid=CjwKCAiAjs2bBhACEiwALTBWZVb1QAIFlRzbEvdeMpOPJuFjTLteaOJljiNmoeAD8UyLeKVf3gQraxoCuO4QAvD_BwE&hvadid=243372549017&hvdev=c&hvlocphy=9031092&hvnetw=g&hvqmt=e&hvrand=1723269426873889369&hvtargid=kwd-415463301108&hydadcr=7471_9322240&keywords=coolant+uv+dye+kit&qid=1668574992&sr=8-12&ufe=app_do:amzn1.fos.18ed3cb5-28d5-4975-8bc7-93deae8f9840

...or just find a bottle of dye and a blacklight, might save some $$

Fire it up and sit under the truck with your yellow cataract glasses and blacklight and watch the suspect area...as it warms up and builds a bit of pressure, you'll see where it's coming from. Solve that problem.

I see no point in pulling both heads and doing a valve job on either head when valve seal or valve springs or anything has nothing to do with the problem at hand. MLS gaskets don't fail....if that's what the LS has on it from GM. I dunno. If it's never been hot, then the heads should be fine, and so should the block, and so should the headgaskets.

Diagnose first, then form a plan of action. I'd much rather spend $75 on a dye kit and lay under the truck for 20 minutes sucking a rum and coke out of a cup with a piece of vacuum hose as a straw than yank of a pair of heads when they shoulda stayed on.

All these MFs suggesting a junkyard engine when yours has a wee coolant leak. Gimme a break lol. Just fixit

 

[mesquito_creek]

@monkeyswrench You did me right again! Pretty sure it’s the rear driver side steam tube block off. The rear crossover on the 05 Lq4 doesn’t have a crossover they just blocked it off. Mine is sitting inns little puddle!

 

[LargeOrangeFont]

@monkeyswrench You did me right again! Pretty sure it’s the rear driver side steam tube block off. The rear crossover on the 05 Lq4 doesn’t have a crossover they just blocked it off. Mine is sitting inns little puddle!

View attachment 1172876 View attachment 1172877

That’s a 10 min and $2 fix. Awesome!

 

[mesquito_creek]

New oring and some aviation/marine sealant!

 

[lbhsbz]

New oring and some aviation/marine sealant! View attachment 1172885

No way. Needs a junkyard engine for sure

 

[mesquito_creek]

No way. Needs a junkyard engine for sure

The most expensive part of the job was the 1/2 a can of permatex aviation sealant I spilled! Lol

 

[monkeyswrench]

The most expensive part of the job was the 1/2 a can of permatex aviation sealant I spilled! Lol

That staff's like gold! Have you seen what RightStuff is up to now?!

 

[lbhsbz]

That staff's like gold! Have you seen what RightStuff is up to now?!

Chemicals are outrageous. I just paid about $450 for a 5 gallon bucket of brake caliper assembly lube