Hello,

I am making a post to share my experience in case any one is searching and looking for advice.
I have a 2015 Class C RV on a Ford E450 chassis with the V10 Triton 6.8L engine. The vehicle only has 21,000 original miles on it and we have done about 3 years of trips on it no problem. I did an oil change only 1,000 miles ago at the most & the oil level looked fine, used Ford Motorcraft oil filter as well. We bought it with 17,000 miles and it ran just fine - no concerns, well maintained.

I was about 100 miles into our next trip and gauges looked fine and all that. I was driving up slight grade at 5,000 RPM and next thing I know, the gauges catch my attention. Oil pressure had dropped to 0, the oil light was on, and it started to rev down to a complete stop within 60 seconds. Nothing sounded strange, just the engine revving down through the gears. The battery, fuel, coolant gauges were reading normal, but oil pressure was 0. I go to start it again and the starter was engaging but not turning over. We got towed up a little bit to a safer spot to troubleshoot more. The next day, I got a 18" breaker bar and an 18mm socket on the crankshaft pulley to try to turn it over by hand. It was stuck. I let up tension on the belt and all the accessory pulleys spun freely, so it's not a locked up accessory.

Anyways, justing posting here for ideas and anyone else who does a frantic google search like I did the past 48 hours to dig as much info as possible. From what I read from other posts, it looks like if it is seized, an engine swap is needed. I was going to drain the oil and check for metal / shavings. Before I start pulling it, are there things I can do in the disassembly process to check out? One major problem is that I can't turn it over to separate the flexplate from the torque converter. What would I do from there if I cant end up separating it? My engine hoist is rated for 2 tons.

 

Definitely sounds like it is seized. You won't be able to turn it over with a 10' breaker bar. Block is probably ruined.

What viscosity of oil did you use?

How steep was the grade? A "slight grade" normally wouldn't have the engine at 5,000RPM.

The only way to get the transmission off of it when it is seized is to leave the torque converter on the flex plate, and take it off after. If you're careful, you can do this while it is all underneath, or you can pull them out together, which is what I'd recommend. With the cost of repairing/replacing the engine in front of you, the cost for a stronger engine hoist is miniscule.

 

Thanks for the response. It was 5w-20 oil, 7 quarts. The grade was 3% and I had it in Tow/Haul mode for all of the trip.

 

I wouldn't personally call 3% a slight grade for a motorhome. Baker grade, for example, averages ~3.5% and it is well-known for taking its toll on normal cars and everything else. Vail pass is about the same.

It should be happy enough with 5W-20 unless you used an obscure brand or something without the proper certifications. Personally, I'd use 5W-30 for this kind of service. That may or may not have helped your situation, but probably would have just delayed whatever happened here.

 

What probably happened when you were going up the grade at that high of rpm the oil got hot and broke down causing bearing failure, most likely a spun bearing. To get it to turn over pull all the plugs and remove the pan and disconnect the rods one at a time and push the piston up in the cylinder. If you find a spun bearing you should be able to turn it over.
Denny

 

Thanks for the reply. I'm hoping it is as simple as a spun bearing. I got to work on it this weekend. I drained the oil and there was close to 6 quarts and there was a slight metallic haze to it. No big chunks or anything catastrophic looking, but definitely a small amount of shiny particles floating on the surface. The oil filter was practically dry - I spun it off and turn it over, just a few drops. I got the whole front end off but had to call it a day. The RV is 90 minutes away from me at a family property, so I think next time, I will be able to pull the engine out and get it on a stand.


A few bubbles & some grass that fell it.

 

The swirls in that oil are the interesting part.

If it lost oil pressure, the filter should still have some oil in it. That's weird.

I'm curious: What make and model of oil and filter were on it?

 

It was a genuine motorcraft FL820s

 

That should be fine. What about the oil?

 

Sounds like the oil pump failed on you .

 

I got the Walmart store brand 5w-20, Supertech Full Synthetic.

 

This is a long shot, but you really have nothing to lose at this time.
Take a filter cutter and open up your oil filter. If it collapsed, or if it (somehow) was the fault of the oil filter, perhaps you can get Motorcraft to buy your replacement engine.

 

Thanks, I saved the oil filter and I'll take a look at it more in depth. It was practically new looking when I took it off and was super clean (and empty)..

 

Here's an update after the teardown and some history.
I bought the RV with 17,000 miles on it. Did an oil change around 19,000 miles with OEM Ford filter. I don't recall what brand was on it before, but it wasn't OEM. The engine seized at the 21,000 mile mark.
As you see in the pictures, the first four pistons were heated to black and were seized to the crank shaft. The oil sump filter is clogged with a fibrous material - which I am thinking is it filter media. If so, that might have been the issue & caused the oil starvation. Then it started eating away at the bearings and sending metal material to the oil pan.

 

That looks bad. Did you cut open the oil filter to see what is going on in there?