MaxxForce 7 engine

[vnorvi]

They have a rough reputation, but it always boils down to 1 issue. The clamp on the air intake hose from the turbo was weak. When it comes off, you are in limp home mode. It’s and easy fix. Either a massive clamp, or drill through the COSMO and out in a couple of sheet metal screws. If you don’t, this will happen for sure. If you do, it’s all good. I’ve always been surprised they didn’t do a recall.

[Trapper2022]

My advise is go and look at the bus company sites. Mixed bag but some people are not to happy with the engine. Good luck with what ever you choose.

Enjoy the journey

[VestaDave]

Trapper makes a point. These engines it seems, are not well suited to stop and go driving. Most of us driving RVs don’t use them like a delivery truck or a bus.

[VestaDave]

One more thought on the MF7. Your Serrano would be considered extreme use so I would suggest that you change oil @5k miles instead of 10k.
Also, the post 2010 diesel world was impacted by EPA rules. No manufacturer has been immune from issues. Last year, Cummins recalled 500,000 vehicles because of faulty emissions systems. VW paid a huge fine because of cheating. Ford is now being investigated. Yes, Navistar’s emission on their big rig engines was a disaster. I believe however that the MF7 might have been the only engine in the Navistar line that was actually certified by the EPA.
So, I’m thinking the 7 is no better or worse than what else is out there.

[Jdsandb]

Originally Posted by VestaDave

One more thought on the MF7. Your Serrano would be considered extreme use so I would suggest that you change oil @5k miles instead of 10k.
Also, the post 2010 diesel world was impacted by EPA rules. No manufacturer has been immune from issues. Last year, Cummins recalled 500,000 vehicles because of faulty emissions systems. VW paid a huge fine because of cheating. Ford is now being investigated. Yes, Navistar’s emission on their big rig engines was a disaster. I believe however that the MF7 might have been the only engine in the Navistar line that was actually certified by the EPA.
So, I’m thinking the 7 is no better or worse than what else is out there.

I really do appreciate all the feedback / input. We've now gone ahead with purchase of the Serrano and for the first two, relatively brief outings (350 mile day trip and another 150 mile trip), everything seems to be running well! Never having experience driving a diesel motor before, I'm starting to get used to it AND to navigating around in the 34' RV! So far - so good!

Thanks again for the input...

[Jdsandb]

Originally Posted by vnorvi

They have a rough reputation, but it always boils down to 1 issue. The clamp on the air intake hose from the turbo was weak. When it comes off, you are in limp home mode. It’s and easy fix. Either a massive clamp, or drill through the COSMO and out in a couple of sheet metal screws. If you don’t, this will happen for sure. If you do, it’s all good. I’ve always been surprised they didn’t do a recall.

Thanks Vnorvi. I'll definitely look into this turbo clamp issue and pursuing this fix, if it hasn't already been done. I'm assuming I can best get access to this part of the motor via the 'dog house' inside, right?

[vnorvi]

Yes the clamp in the top very easily seen in the dog house. It is a about a 4 inch tube going into the engine. The clamp looks like a radiator hose clamp, and in fact I think that was what they originally used. They saved 5 dollars in the clamp but created a huge reputation issue. The engine maker has a repair kit which amounts to a more robust clamp and some glue. (Seriously). We used that but my mechanic also drilled through the clamp in two spots and pit in sheet metal screws to hold it on. All good since.

[Jdsandb]

Originally Posted by vnorvi

Yes the clamp in the top very easily seen in the dog house. It is a about a 4 inch tube going into the engine. The clamp looks like a radiator hose clamp, and in fact I think that was what they originally used. They saved 5 dollars in the clamp but created a huge reputation issue. The engine maker has a repair kit which amounts to a more robust clamp and some glue. (Seriously). We used that but my mechanic also drilled through the clamp in two spots and pit in sheet metal screws to hold it on. All good since.

OK so now - how in the world do you remove the engine 'dog house'?? I've loosened the 4 holding clamps but can't even get the cover to budge! Clearly it must slide backwards, but...

[Jdsandb]

Originally Posted by Jdsandb

OK so now - how in the world do you remove the engine 'dog house'?? I've loosened the 4 holding clamps but can't even get the cover to budge! Clearly it must slide backwards, but...

Finally removed the dog house and can see now the turbo hose & clamps in question. Ordered the replacement kit and hope to get it installed in the next week!

[s3anpow]

can anyone help me out with a mf7 low pressure fuel pump? The fuel pump is not sending fuel to the secondary filter. The lift pump does but it drains back down after awhile. I'm not used to these pumps so if anyone could help me out i would appreciate it a lot. Thanks

[Hork]

Originally Posted by Jdsandb

Finally removed the dog house and can see now the turbo hose & clamps in question. Ordered the replacement kit and hope to get it installed in the next week!

Where do you order the kit from?

[Jdsandb]

Ordered the kit from; Buddy Gamel - bgamel@alternatefuel.com. He has access to warehouse parts for Maxforce 7 motors.

[Hork]

Thanks for the reply. Pulled the trigger on a Serrano today; pretty excited about it.

[Marty1096]

Originally Posted by mooka

Hi All

New member here hope this posts. As owner of a 2015 ghost with maxx force 7 with 20,000 miles now and have had zero problem with the engine.

Update on engine please...