Head Gasket Job LMM

[owntheroad]

Hi everyone.

Been looking at possible symptoms of HG failure on my LMM. Started with pressure after being shut off overnight, then slight coolant loss, and just recently seeing the temp gauge go from running temp, all the way down and then a few minutes later back up again within the first 15 mins of driving. It was in the back of my mind that this may be an EGR issue as well, however I no loner feel that may be the case.

Any tips on doing this job on a LMM? I seem to be hearing that pulling the en gang is possibly the best way to go about it. Also, I really don't have a practical way to get these heads to a machine shop. Has anyone done this without having the heads decked/machined? Are there any tips on prepping the heads or checking them myself?

I also may have to wait until the weather warms up a but before I can get this as the garage that I plan to work in currently has a boat inside and can't be moved out until the temperatures start to warm up. Is there anything I can do to minimize the risk of damage or major issues in the meantime while I wait for some normal temperatures? This is a daily driver but currently isn't doing any towing or hard work. I have heard of some running with the coolant cap loose or drilling a small hole in it to relieve pressure in the system. Would this be a bad idea?

When I do get to this job, I will be planning on using Mahle grade c gaskets as well as head studs. Looking at ARP and Xotic. Has anyone had any experience running Xotic studs, or should I just go with ARP?

Thanks everyone.

 

[08lmm72mm]

I've heard of people stretching the Xotic under stock power. Stay stock or go arp imo.

 

[owntheroad]

I've heard of people stretching the Xotic under stock power. Stay stock or go arp imo.

Good to know, thanks!

 

[Bdsankey]

I've heard of people stretching the Xotic under stock power. Stay stock or go arp imo.

Can't say I've seen that in the ~3-4 dozen sets we've used and sold here.

 

[08lmm72mm]

I've heard it, never witnessed.

 

[660catman]

I used ARP in my LML last year as recommended on here. I didn’t do the work but the engine was pulled. I was told it’s easier. Also recommended was a water pump change.


2013 Sierra SLE 2500HD Crew Cab

 

[2004LB7]

I used ARP in my LML last year as recommended on here. I didn’t do the work but the engine was pulled. I was told it’s easier. Also recommended was a water pump change.


2013 Sierra SLE 2500HD Crew Cab

Studding the back by the firewall can be difficult. Pulling the engine makes lifting and installing the heads a breeze. But you have the extra work of pulling and installing the engine, but it kinda offsets the harder work of doing it in place. There are even some that swear by removing the cab. Different people have different preferences

I think, if you want to try and do it in place, you can put the stud in the head before placing the head on the block. That gives you the clearance needed for the back studs. The rest can be installed after it's down. Might also only be applicable to the earlier generations as the cabs have been getting taller and taller every year

 

[owntheroad]

Thanks for the replies, I think I'm going to try it by pulling the engine.
As for the heads and not likely able to get them to a machine shop. Is there anything I can check or any specific surface prep that you can recommend before reassembling?

 

[2004LB7]

Quality straight edge like a machinist straight edge and not your typical level from the hardware store and feeler gauges. Check horizontal, vertical and diagonal

 

[ZeroGravity58]

I left the motor in when I just did my lbz, I did pull both fenders and it made a huge difference. Left the core support so I would have to charge A/C.

 

[Dozerboy]

No way I would do this job and not have the heads machined or buy new ones! What if your head is cracked? Your looking at 30hrs+ of work and over $1,000 in parts/gaskets. Just to maybe have the same problem.

I too did my LBZ without pulling the engine or cab. I just took the hood off. However I'm not a big guy, so it ain't hard for me to get in there.

I wouldn't worry about driving it until summer. I drove mine for a while. Even took on a 3,000 mile trip pulling my 9k+ lbs camper. Just watch the coolant and I would release the pressure on the coolant system when I stopped. More than anything else worried about damage to the coolant hoses and ETC with that much pressure for that long. I definitely don't recommend drilling the cap or leaving it loose. I experimented with that and I boil the coolant immediately. However I'm making a lot more power and drive a lot harder than you do probably. Also I'm in TX so it's hot. Maybe for the winter a loose cap would be fine.

 

[turbovan]

Sure its not the EGR cooler leaking?

Everyone Dmax head job, they've been machined and they are out of spec.

I have some pressure tested and planed heads I am selling, LMM units, only 60k miles on them.

I lift the cabs, but then I have a hoist. I've done one in the truck and never again.

just doing a Cummins now, first one, lifted cab, the other shops call me nuts but I'm old now, tired of bending over crap. Can't figure out how'd they get the studs in with the sitting over half the engine.