..Yep..5.9 runs fine with cracks but if your 30 miles off shore and the crack goes all the way its hard to call a tow truck in a Gale Storm...On land no big deal at all i'll agree. This was Equipment but i have done many Marine also.
heck that is nothing, i lifted the head on my 99 24 valve cummins @44psi boost and blew out some coolant when they pulled the head and sent it out the guy quit counting cracks at 70, i could not believe how many it had, and it was running great still. It had 275k miles on it at the time.
have hardened seats put in that puppy and keep on using it! cracks from intake to injector hole are usable as long as a machine type seat is installed. there is no water passages in that area on the 2 valve heads. both intake and exhaust seats should be changed over while it's at the shop and taken apart. the factory induction hardens the iron integral seats,and they become brittle,and prone to cracking.
The Cummins 5.9 head can have these cracks and not have any symptoms as the cracks don't make it to the coolant side.If they do it blows combustion pressure into the rad side and overheats,but it may put so little at first it is'nt noticeable!
..Yep..5.9 runs fine with cracks but if your 30 miles off shore and the crack goes all the way its hard to call a tow truck in a Gale Storm...On land no big deal at all i'll agree. This was Equipment but i have done many Marine also.
krismaze 6 months ago
heck that is nothing, i lifted the head on my 99 24 valve cummins @44psi boost and blew out some coolant when they pulled the head and sent it out the guy quit counting cracks at 70, i could not believe how many it had, and it was running great still. It had 275k miles on it at the time.
nsaanity 6 months ago
how did the cracks form?
arnoldt14 11 months ago
This reminds me of the head on my Mercedes 300-SDL, it was cracked into the injector cup and NFG.
dollman0 1 year ago
thats a 5.9 characteristic, almost all 5.9 heads crack, guys even reuse cracked heads on a rebuilt engine and they run fine.
NathansBackwoods 1 year ago
ouch that hurts
WMH435 1 year ago
have hardened seats put in that puppy and keep on using it! cracks from intake to injector hole are usable as long as a machine type seat is installed. there is no water passages in that area on the 2 valve heads. both intake and exhaust seats should be changed over while it's at the shop and taken apart. the factory induction hardens the iron integral seats,and they become brittle,and prone to cracking.
jmh11962 1 year ago
I didn't know cummins had two valves per cylinder, i thought they had 4 like the dura max.
I guess we learn something new everyday.
5stars
roboman79 2 years ago
@roboman79
12 valve cummins have 2 per cylinder. 24 valves have 4 per cyl
Dodgeram901 2 years ago
the valve holes look like eye balls.
chevy490 2 years ago
The Cummins 5.9 head can have these cracks and not have any symptoms as the cracks don't make it to the coolant side.If they do it blows combustion pressure into the rad side and overheats,but it may put so little at first it is'nt noticeable!
krismaze 2 years ago
So what were the symptoms from the cracks?
2253benjamin 2 years ago
It looks like that thing had a hard life.
NathansBackwoods 2 years ago
This comment has received too many negative votes show
that's what happens when you buy cummins
sk8forlife90 2 years ago
@sk8forlife90 dude this can happen with any engine any make.
roboman79 2 years ago
cummins especially
sk8forlife90 2 years ago