Cummings 5.9L Head Gasket

[johnyquest69]

I have a Case power unit 6590T that is a 5.9L 12 valve Cummings motor. I had an exhaust leak and went to replace exhaust manifold. After removal, I found head had been damaged. I ordered a new head from one of the online tractor parts stores. After replacing, I now have seepage from head gasket. It cranks great and runs well, but noticed now I have what looks like wet stacking coming out of exhaust. I did not see this issue before replacing head. Coincidence that it has went bad? I plan on getting another gasket and maybe taking new head to machine shop for them to check if it’s within specs although it is new. I’m just wondering if I need to order a turbo also, or if the slight leak at head would have anything to do with it. Thanks for any advice!!!

 

[Ericp351]

Did you at least chase all studs and check block + head for flat? Would be helpful to know how original head failed/ what was problem.

 

[timcasbolt]

*Cummins

 

[johnyquest69]

Did you at least chase all studs and check block + head for flat? Would be helpful to know how original head failed/ what was problem.

I did not chase threads. I should have checked head, but it was new. Two of the exhaust ports rusted away on head that was removed. Thanks!

 

[johnyquest69]

*Cummins

My bad! I knew that! LOL!

 

[showcrop]

Before your repair was the exhaust leak fairly dry or was it pretty oily?

 

[johnyquest69]

Before your repair was the exhaust leak fairly dry or was it pretty oily?

Pretty dry

 

[Fritz Maurer]

You do not indicate whether the head was complete or bare. If you used all your old valves you may have an issue here.
If the head was loaded then anything is possible. Take it apart very carefully and pay attention to any clues like any wet with fuel cylinders, any evidence on the head gasket of compression or coolant crossing boundaries into areas where they’re not supposed to go…and don’t let anyone help you unless they know what they are doing. Too many people unbolt things as fast as they can and fling them to the far corners of the shop…. this is the last thing you need right now.
I wouldn’t order a turbo right off… unless you see oil at the turbo outlet and it is dry where it bolts to the manifold.
Mark the injectors to the cylinder each came out of, so if you see a suspicious wet spot in a cylinder or a port, you will know which injector(s) to look at.
What is this seepage you speak of? Between head and block? Possible blowing of coolant out exhaust?

 

[Destroked 450]

There’s been a good bit of talk on the Cummins forum about new heads not being flat resulting in head gasket issues
5.9 Cummins has reusable torque to yield head bolts, those bolts have a max bolt length allowed for bolt stretch.
What brand head gasket did you use, Cummins, Felpro, Mahle are the better brands
Although the head gaskets come with print o seal sealant on the gasket for dry insulation, I spray a coat of Copper Spray O Gasket adhesive on both sides of the head gasket before insulating it

 

[Levi81]

There’s been a good bit of talk on the Cummins forum about new heads not being flat resulting in head gasket issues
5.9 Cummins has reusable torque to yield head bolts, those bolts have a max bolt length allowed for bolt stretch.
What brand head gasket did you use, Cummins, Felpro, Mahle are the better brands
Although the head gaskets come with print o seal sealant on the gasket for dry insulation, I spray a coat of Copper Spray O Gasket adhesive on both sides of the head gasket before insulating it

What is your go to head gasket brand?

 

[waugh621]

What is your go to head gasket brand?

The question wasnt adressed to me but i like OEM or felpro
Nate

 

[Levi81]

The question wasnt adressed to me but i like OEM or felpro
Nate

Thank you for the response

 

[Ericp351]

Given the info on hand- I'd tear her back down asap. No need to tolerate trouble with new head. Cost- bit of time and $55 in gaskets. Your new/ rebuild may have been crap! Reason it was "in the system". Ain't right = ain't right! Good luck and this time try to work slowly and check well- step-by step. The snake a guy didn't look for bites. Don't forget to gauge any bolts for stretch! Even cheapy card-stock templet better than nothing! Can queer your day. My smallest cummings = C series, but similar set-up.

 

[used red MN]

On your turbo check for side to side play, should be minimal. If the compressor wheel is found touching the housing it obviously needs replaced. This is a power unit so what service is it in? Have you ever idled it much? If not it just may be that you never saw “wet stacking” before because you basically started it and put it to work. Now you have probably idled it more than it has been for a long time checking this gasket leak. May give this a consideration, disable the fuel solenoid and just crank the engine. Listen for an even cranking sound, each compression stroke should load the starter equally. If it sounds uneven, it may indicate a cylinder that is not producing as much compression as the others which may produce the wet stacking(is the head really a POS?). If there are concerns from the cranking test and this is a mechanical engine it can be followed with an injector line “crack test” to verify all cylinders are doing their fair share.
It looks like Eric likes running them “cummings” engines as well!

 

[Destroked 450]

On your turbo check for side to side play, should be minimal. If the compressor wheel is found touching the housing it obviously needs replaced. This is a power unit so what service is it in? Have you ever idled it much? If not it just may be that you never saw “wet stacking” before because you basically started it and put it to work. Now you have probably idled it more than it has been for a long time checking this gasket leak. May give this a consideration, disable the fuel solenoid and just crank the engine. Listen for an even cranking sound, each compression stroke should load the starter equally. If it sounds uneven, it may indicate a cylinder that is not producing as much compression as the others which may produce the wet stacking(is the head really a POS?). If there are concerns from the cranking test and this is a mechanical engine it can be followed with an injector line “crack test” to verify all cylinders are doing their fair share.
It looks like Eric likes running them “cummings” engines as well!

Their good engines
I have a 5.9 12 valve in my F-450
8.3 12 valve in my F-800
Had Big Cam 400’s in my Ford LTL9000 and 359 Pete

 

[used red MN]

Their good engines
I have a 5.9 12 valve in my F-450
8.3 12 valve in my F-800
Had Big Cam 400’s in my Ford LTL9000 and 359 Pete

The point is the actual name is “Cummins” I would be a fool to question the quality of their engines.

 

[johnyquest69]

You do not indicate whether the head was complete or bare. If you used all your old valves you may have an issue here.
If the head was loaded then anything is possible. Take it apart very carefully and pay attention to any clues like any wet with fuel cylinders, any evidence on the head gasket of compression or coolant crossing boundaries into areas where they’re not supposed to go…and don’t let anyone help you unless they know what they are doing. Too many people unbolt things as fast as they can and fling them to the far corners of the shop…. this is the last thing you need right now.
I wouldn’t order a turbo right off… unless you see oil at the turbo outlet and it is dry where it bolts to the manifold.
Mark the injectors to the cylinder each came out of, so if you see a suspicious wet spot in a cylinder or a port, you will know which injector(s) to look at.
What is this seepage you speak of? Between head and block? Possible blowing of coolant out exhaust?

 

[johnyquest69]

Pulled the head today. It was a complete unit. Abilene Machine. Seepage was coolant and maybe oil also. Not a turbo issue. Saw oil on 2 pistons. Not from rings.This all started with an exhaust manifold leak. Not burning oil and run good. Manifold leak made thermostat hot. Maybe head…maybe gasket. One water port on gasket questionable. Carrying head to machine shop tomorrow. Checked valves ok I think. I have a friend who is pretty sharp helping me and he is somewhat stumped. Thanks for the reply!

 

[johnyquest69]

On your turbo check for side to side play, should be minimal. If the compressor wheel is found touching the housing it obviously needs replaced. This is a power unit so what service is it in? Have you ever idled it much? If not it just may be that you never saw “wet stacking” before because you basically started it and put it to work. Now you have probably idled it more than it has been for a long time checking this gasket leak. May give this a consideration, disable the fuel solenoid and just crank the engine. Listen for an even cranking sound, each compression stroke should load the starter equally. If it sounds uneven, it may indicate a cylinder that is not producing as much compression as the others which may produce the wet stacking(is the head really a POS?). If there are concerns from the cranking test and this is a mechanical engine it can be followed with an injector line “crack test” to verify all cylinders are doing their fair share.
It looks like Eric likes running them “cummings” engines as well!

Thanks for the info!

 

[johnyquest69]

Given the info on hand- I'd tear her back down asap. No need to tolerate trouble with new head. Cost- bit of time and $55 in gaskets. Your new/ rebuild may have been crap! Reason it was "in the system". Ain't right = ain't right! Good luck and this time try to work slowly and check well- step-by step. The snake a guy didn't look for bites. Don't forget to gauge any bolts for stretch! Even cheapy card-stock templet better than nothing! Can queer your day. My smallest cummings = C series, but similar set-up.

Thanks!