• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

FMTV 3126 Engine options

Wingnut13

Well-known member
235
562
93
Location
Strafford, NH
I’ve got a 3126 and the same ballpark too. With 13k miles on the clock I swapped my oil pump(used school bus take out). And just for fun I’m running 10W30 as spec’d and it’s ok. 40psi at speed when warm but will flash the low oil pressure light at idle. I will switch back to 15w40 soon and I’ll check my oil cooler plate too.
 

Attachments

GeneralDisorder

Well-known member
Steel Soldiers Supporter
2,034
5,224
113
Location
Portland, OR
I’ve got a 3126 and the same ballpark too. With 13k miles on the clock I swapped my oil pump(used school bus take out). And just for fun I’m running 10W30 as spec’d and it’s ok. 40psi at speed when warm but will flash the low oil pressure light at idle. I will switch back to 15w40 soon and I’ll check my oil cooler plate too.
The Army only allows OEA (Oil, Engine Arctic) in -15F to -50F operation. For all other environments the Army uses 15w40.

As for what OEA actually is - depends on when you ask. Right now it's something synthetic that is thinner...... that's all I know. Probably a 10w30 or a 0w30 synthetic. It didn't used to be synthetic. It's been changed over the years.

I would not run 10w30 in these engines. Honestly I don't run that dishwater in anything I own except maybe the lawnmower (but likely that's just SAE 30 since cold operation isn't a concern). All my civilian vehicle engines get Amsoil 5w40. I prefer the larger viscosity spread for all-year operation and I have literally millions of miles on the Amsoil 5w40 - we run it in 95% of the oil changes we perform at my shop. Everything up to about ~400 wheel HP on a 4 cylinder. Above that we run 5w50. Where we make the call to switch to 50 depends on engine size and output...... Not a single lubrication related failure to be seen that wasn't the operators fault for running it dry.

That said - you have a 3126b with a flashing low oil pressure light..... GO DIRECTLY TO ->CHANGE YOUR PUMP. Do not pass go. Do not collect $200.

My C7 in my A1R runs Amsoil Signature 15w40. I don't foresee having any lubrication related problems. Also changed my oil pump - no change in pressure (~22 psi hot idle before and after) - just a huge change in piece of mind now that I know what's in there.
 
Last edited:

Skyhawk13205

Well-known member
157
269
63
Location
Alaska
The Army only allows OEA (Oil, Engine Arctic) in -15F to -50F operation. For all other environments the Army uses 15w40.

As for what OEA actually is - depends on when you ask. Right now it's something synthetic that is thinner...... that's all I know. Probably a 10w30 or a 0w30 synthetic. It didn't used to be synthetic. It's been changed over the years.

I would not run 10w30 in these engines. Honestly I don't run that dishwater in anything I own except maybe the lawnmower (but likely that's just SAE 30 since cold operation isn't a concern). All my civilian vehicle engines get Amsoil 5w40. I prefer the larger viscosity spread for all-year operation and I have literally millions of miles on the Amsoil 5w40 - we run it in 95% of the oil changes we perform at my shop. Everything up to about ~400 wheel HP on a 4 cylinder. Above that we run 5w50. Where we make the call to switch to 50 depends on engine size and output...... Not a single lubrication related failure to be seen that wasn't the operators fault for running it dry.

That said - you have a 3126b with a flashing low oil pressure light..... GO DIRECTLY TO ->CHANGE YOUR PUMP. Do not pass go. Do not collect $200.

My C7 in my A1R runs Amsoil Signature 15w40. I don't foresee having any lubrication related problems. Also changed my oil pump - no change in pressure (~22 psi hot idle before and after) - just a huge change in piece of mind now that I know what's in there.
5w-40 is a good range, looks like from -30 to 122F, cat has a good chart for the temps to run. I end up running 15w-40 in my 3126. I wonder if the HUEI system puts more stain on the oil pump? My oil pressure seems to be around 20-30 at temp at idle, and about 60-70 in cruise. I have the 6pz just waiting for the day when my oil pump starts to die.4A09CB16-6599-4EE9-B6B9-81663FC68B77.jpeg
 
Top