Doing Head Gaskets looking for pointers

[thecritter]

Looks like I am going to be replacing head gaskets. Engine was not hot but was at operating temp. Heading home, turned into my driveway got out to check mail 2 min tops. Get back in Jeep all the dash lights are on figure ok driveway is ,25 miles so no problem. In the .25 mile trip down driveway it puked all the coolant out the exhaust. Pulling heads today to take a look and see the extent of damage. Engine was a new long block replaced by jeep 90K ago had cam issues.

So far will be replacing
Head gaskets
Head Bolts
Thermostat
Water pump
Spark Plugs

Are there any other parts that should be replaced while this far into the engine? T

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[JEEP4U]

I would utilize ARP head studs/nuts. Instead of the stock torque to yield bolts.

 

[thecritter]

I would utilize ARP head studs/nuts. Instead of the stock torque to yield bolts.

Used those on my 6.0 did not know were a thing for the 3.6 Pentastar. Thanks for the suggestion will look into it.

 

[fat_head]

Your second engine? How many miles total do you have on the Jeep out of curiosity? Are you going to have the heads machined?

 

[thecritter]

Your second engine? How many miles total do you have on the Jeep out of curiosity? Are you going to have the heads machined?

Yes the second one. My guess they did not loosen head bolts and retorque headbolts but that's just a guess at this point. Miles = 168k other than front suspension needing bushings still solid as a rock.
Made it this far this afternoon... more to come

 

[fat_head]

Yes the second one. My guess they did not loosen head bolts and retorque headbolts but that's just a guess at this point. Miles = 168k other than front suspension needing bushings still solid as a rock.
Made it this far this afternoon... more to come

Nice! I love pics. Also examine them rockers/cams closely! Won't get any easier to fix them now!

 

[Joe S]

The timing chain has to come off to get the heads off, so timing chain. Once you are there the oil pump is also attached to the timing chain. At this point, might as well rebuild it. But, I hope you have better luck than I did. I rebuilt my JK 3.6 during the china virus so parts were hard to find. I ended up buying a complete rebuild kit, including the timing chain set, water pump, oil pump, lifters, gaskets, bearings, etc. for $500. A name brand timing chain set is about $400 by itself. Once it was back together, it wouldn’t start. The bolt holding the timing chain idler pulley broke. I tore the engine down again and replaced the bolt and triple checked that it was torqued properly. The jeep ran great for about 200 miles before that same bolt loosened up and ended up stripping the block. Moral of the story, use quality parts and avoid eBay. My only guess is that the timing chain wasn’t to spec. I ended up buying an engine with 31,000 miles for $4k.

 

[drrags]

Dang... I gotta do the same thing next week. 60 psi in #2 cylinder. 2018 JK with 59,020 miles, but one year over the warranty. I'm following your thread.

 

[roaniecowpony]

Looks like I am going to be replacing head gaskets. Engine was not hot but was at operating temp. Heading home, turned into my driveway got out to check mail 2 min tops. Get back in Jeep all the dash lights are on figure ok driveway is ,25 miles so no problem. In the .25 mile trip down driveway it puked all the coolant out the exhaust. Pulling heads today to take a look and see the extent of damage. Engine was a new long block replaced by jeep 90K ago had cam issues.

So far will be replacing
Head gaskets
Head Bolts
Thermostat
Water pump
Spark Plugs

Are there any other parts that should be replaced while this far into the engine? T

Mine did something similar at 34K. I pulled it out and put in a take out from a 2024 Gladiator.

Invest in a precision ground, machinists straight edge along with some feeler stock from about .001 to .005" so you can check the deck of the block and heads for flatness. Look for small local dips. The block is diecast and can have residual stresses that can cause some warping. The head gasket blew for a reason. Best to find out why, before you put it back together.

 

[Old Jeeper]

Looks like I am going to be replacing head gaskets. Engine was not hot but was at operating temp. Heading home, turned into my driveway got out to check mail 2 min tops. Get back in Jeep all the dash lights are on figure ok driveway is ,25 miles so no problem. In the .25 mile trip down driveway it puked all the coolant out the exhaust. Pulling heads today to take a look and see the extent of damage. Engine was a new long block replaced by jeep 90K ago had cam issues.

So far will be replacing
Head gaskets
Head Bolts
Thermostat
Water pump
Spark Plugs

Are there any other parts that should be replaced while this far into the engine? T

Here is a TRICK that may save you time. Carbon can build up inside the cylinders and on the valves and bottom of the head. Its not as bad now as it was back in day when gas had LEAD into, WOW, cleaning the head was an all-afternoon job with scrapers and steel wire wheel etc.

But there is a way around it: IF you can start your Jeep and let it run up to operating temp, then with the engine running and a couple of 12 oz cans of WATER and a helper.

Pour (drizzle) the water down the intake while your helper is revving the engine.

This is legit, been doing it to the ranch truck, tractors, daddys car, mama caddy, my corvettes since the 60's

Now I am an engineer and to answer your question: Hot engine, Cold water, Carbon builds up and when it is hit with a splash of water, the carbon explodes and breaks off the combustion chamber, water turns to steam.

I do suggest you disconnect the exhaust pipe right before the converter, if not the carbon will burn off anyhow.

Go for it East Texas, we had a farm and ranch out side of Texarkana...

 

[thecritter]

A little late with my update. After pulling valve covers and seeing scored cams I was not in the best of spirits. Engine got much hotter than first thought.
The lower intake is slightly melted strike 1
The cams are bad strike 2.
Too many miles not necessarily strike 3 but why not start over at this point.

Ordering a new complete engine includes everything with not enough miles to burn 1/4 tank of gas on the odometer. It's not the cheapest route, but best for longevity hopefully.

My new question most of the videos online show pulling transmission with the engine. Is it easier to pull together and disconnect out of the Jeep? Most are swapping both so need to pull both, but do I or should I just pull engine and leave transmission installed.

 

[CarbonSteel]

Make sure the heads or block are not cracked as well. A number of us on the forum have experienced it. High operating temps and 11:1 compression is a good recipe for either.

 

[mwilk012]

That engine is smoked, not even a viable core imo. Replace the complete assembly.

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