MaxxForce 7 aka 6.4L Ford PowerStroke

I know the Duramax likes to break the crankshaft. Maybe this could be happening also? All I hear about the 6.4 is how unpredictable it is. It is capable of gobs of power, but it is unreliable. I've never owned a 6.4, only speaking on what I've been told from others. Good luck

Check for endplay on the crank, had a few with issues.

If belt too short the belt may be touching itself around the pulleys….or possible water pump bearing…also if turbo was really bad it can kill the particulate filter,,not replated to belt problem …but we had that happen on one..also had one that had wrong tensoner and someone stretced the belt on to tensioner but actualy the spring in it worked the opposite direction form the way it should have

Hi Rex, The Ford version 6.4 is built different than the MaxxForce 7 MaxxForce 7 vs. Ford PowerStroke- Medium Duty Truck Diesel Engine Comparison - Bing video There is a link at the end that has some interesting failure information, you might want to read about. The MaxxForce engines have some issues, but so does everything else. One big issue is the fuel dilution problem and the other is…

Glenn, very interesting. Will read and watch this tonight. Some other thoughts below. I think the MF 7 can be kept alive by adding or using the regen inhibit feature. And frequent enough oil changes to keep the soot level down or the addition of some type of soot separator oil filter. I think the DPF's are under-sized on a lot of these engines. Most are in stop-and-go operation. So when they…

Hi Rex, In my experience with DPF, idle times are the biggest enemy. These DPF's require constant high temps to minimize soot accumulation. That means run them at higher RPM consistently. I have dealt with regen problems on farm tractors and trucks too often because people were not running them hard enough. Stop and go running and prolonged idling is the worst thing for these systems.

Something that seems to be ignored by all builders of anything is insulating the exhaust system. i know it can be a PIA to install, maintain and move when access is needed. But if the DPF can be kept at 600F or better some soot will burn off on it own. If I had stationary or off road equip or skid steers or whatever I would at least try to insulate.

The video compares the 6.7L to the MF7, Not the 6.4L. I don't fully agree with his conclusions about implied durability with iron vs aluminum. The 6.7L has shown to be quite reliable in it's 10+ year run, The 6.4L/MF7, not so much!

The Duramax is also a success story when talking about cast iron being mated to aluminum.

I am not familiar with the ford power stroke engine but we had a Sprinter with the Om642 diesel engine a few months back that was shredding the accessory belt every couple of days. We went through 2 belts and tensioners until I decided to drive it after putting the third one on. I noticed after a short test drive a shiny drop of fluid on the inner edge of one of the pulleys. The belt appeared…

Hi Alan, That is great to know, that happened a lot with the old Ford 4.0 engines also, they were always spinning balancer rings. I suspect this will become more common with this engine design.

As a side note: Maybe using a paint pin and marking the center and outer ring would possibly confirm this problem? Just a thought, if a chassis camera is not available. Years ago, I even used a compact HP camera set to video mode to capture test drive events. That was hard on the camera though. I have seen a couple of posts where people used their Go Pro cameras also. I have not tried that.

You can get on eBay now and buy the little micro mini– cam and micro mini cube cam's for $8 or $10 each glue them on and go take a ride if they fall off. well you did not have a lot to lose. Happy Easter to you and yours . And God Bless

Alan, very interesting. I have a Go-Pro type camera. I will give that a try. Have to get it out of the box and RTFM. Sat. I got pictures of the balencer from several angles and it looked fine. My gut said balancer when problem was called in. Belt Installation can be a little tricky but not that tricky. I do not know the other shop but assume (I know) they aren't 100% incompetent. Your answer and…

Post a pic of belt set UP​.​MAYBE some one can see the problem…like I said we had one that tensioner was spring loaded backward but someone had got the belt on anyway

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