The infamous Grid Heater Nut

[BigPapa]

I’ve searched and can’t find a thread specifically about the infamous Grid Heater Nut and I have questions. Is this a 6.7 issue or only certain years? Is it a Ram only issue?

I ask because we have 561 6.7’s in our bus fleet and 26 in our White Fleet, from 2007 to current year models, and to the best of my knowledge, we’ve not had a single instance of the nut coming loose and getting into the engine. We have replaced a total of 6 Intake Covers, the first one in 2017 on an ‘08 and the latest ones on a ‘14 model. The majority of these was due to the stud for the cable breaking off. I’ve assumed this was due the tech not being careful and snapping the plastic.

I’m also on a School Bus forum and there’s no talk of it there. There certainly is quite a bit of chatter on it here and thought I’d ask.

 

[NIsaacs]

Do the bus's even have a grid heater? I thought that was a Dodge/Ram thing.

https://www.turbodieselregister.com/posts/2653658/

https://r.search.yahoo.com/_ylt=AwrO_Xuewe5i4MAU0zBXNyoA;_ylu=Y29sbwNncTEEcG9zAzEEdnRpZAMEc2VjA3Ny/RV=2/RE=1659843102/RO=10/RU=https://www.youtube.com/watch?v=Hi2rkVto57Y/RK=2/RS=NJ_bM6DIEIQAlHiW6_Qz0lNG5wg-

https://www.cumminsforum.com/threads/2013-28-000-miles-possible-spun-bearing.2215329/post-25794977

https://www.cumminsforum.com/threads/grid-heater-bolt-falling-into-engine.2238009/post-26019497

 

[BigPapa]

Do the bus's even have a grid heater? I thought that was a Dodge/Ram thing.

Yes, they do. This is from the ESN for a ‘22 bus. The pics are from an eBay listing.
The bus heater grid is 12 volt, 194 amps. I have no idea what the Ram heater grid specs are. They aren’t on QuickServe.

 

[sag2]

The nut melts off because the relay sticks on. If they use a different relay they should be fine.

 

[Wiredawg]

Do the bus's even have a grid heater? I thought that was a Dodge/Ram thing.

https://www.turbodieselregister.com/posts/2653658/

https://r.search.yahoo.com/_ylt=AwrO_Xuewe5i4MAU0zBXNyoA;_ylu=Y29sbwNncTEEcG9zAzEEdnRpZAMEc2VjA3Ny/RV=2/RE=1659843102/RO=10/RU=https://www.youtube.com/watch?v=Hi2rkVto57Y/RK=2/RS=NJ_bM6DIEIQAlHiW6_Qz0lNG5wg-

https://www.cumminsforum.com/threads/2013-28-000-miles-possible-spun-bearing.2215329/post-25794977

https://www.cumminsforum.com/threads/grid-heater-bolt-falling-into-engine.2238009/post-26019497

I have a 2018 6.7L ISB in my 2020 MH and it has the grid heater too.

 

[NIsaacs]

The nut melts off because the relay sticks on. If they use a different relay they should be fine.

It seems like this issue has been ongoing for a lot of model years. My '21 had the Y76 recall, Intake Air Heater Relay. No issues were found, recall completed.

 

[BigPapa]

The nut melts off because the relay sticks on. If they use a different relay they should be fine.

Ah, hah! So, the real problem is the relay. That would pretty much make it a Ram issue and from Nick’s post about the “Y76 recall” Ram is taking care of it. What year models was the recall for?

 

[Newsa]

This may be related to the relay, but I remember Cerberusiam speaking about a combination of a ground path fault possibly causing the grid nut to conduct electricity and the EGR bringing hot unburned gasses. Not sure about specifics on the ground path fault and if it is a fault in the relay/control or not.

 

[NIsaacs]

This may be related to the relay, but I remember Cerberusiam speaking about a combination of a ground path fault possibly causing the grid nut to conduct electricity and the EGR bringing hot unburned gasses. Not sure about specifics on the ground path fault and if it is a fault in the relay/control or not.

It might be this recall, Y08. The fix is some RTV

https://r.search.yahoo.com/_ylt=Awr...9964.pdf/RK=2/RS=d8Z_syYXWTWyH9xUkyLNWqMEsB8-

 

[BigPapa]

That’s only for the ‘21 models.

 

[NIsaacs]

That’s only for the ‘21 models.

I didn't think the thread was year specific. Just grid heater problems.

 

[BigPapa]

I asked if it was specific to particular year models. If that recall is the only one, it would seem that Ram is saying it’s only a problem on the ‘21 models.

 

[sag2]

They changed the relay design in 19. That's the only ones there saying can stay on because of water intrusion.

 

[BigPapa]

This is the Relay on our buses. Freightliner 06-61156-000.

 

[ramshackle]

I deleted the grid heater and put on The GDP intake manifold.

 

[ramshackle]

Don't Drop!!