Greetings All,

I've got a long-winded question about potential failure of a tired 351W. Here's the background.

My '84 F250 sees maybe 5000 miles per year. At 10mpg, it's no longer a daily driver. The truck has about 220k miles on it and does everything I could ask of it. In the winter, it's my ride to work when the roads are nasty. In the summer, it hauls a pickup camper, sometimes towing our Jeep, too.

This truck has been remarkably reliable. With one caveat (more on that later), I'd be fine running the engine as is, considering the limited usage. Even though the engine is getting up there, it could easily keep going reliably for many years like this.

My big question: What usually happens when an engine gives out due to high miles? Am I likely to be stranded with something like a rod through the oil pan? Or is it more likely I could limp home on 7 cylinders in a cloud of blue smoke?

Here's the rub. My wife and I often travel to some very remote locations when camping. That would be a very bad time to get stranded. I'm fine taking my chances around town. Worst case is I'd be late for work and have to spend $100 for a tow home. Not so out in the boonies, though. Getting home could get real spendy real quick, a thousand miles from home and hours from the nearest tow truck.

I'm fine taking my chances with "field-repairable" issues like a radiator leak or a carb problem. Those are the type of problems where I'd be fine after reaching civilization to get parts. No, my big worry is a major failure that can't be fixed (or at least patched) by the side of the road. Since I'm not going to abandon the truck, the only other options would be a very spendy long-distance transport or paying a local shop. Neither potential option is very appealing to my cheap nature.

So whaddya all think? What typically happens when a high mileage engine gives up the ghost? Catastrophic failure? Or just reduced performance, and/or smoke and noise, but still able to limp home? I'm not especially worried about saving this engine as a rebuildable core, if it comes down to that.

 

I think it depends on what you are doing to the engine. If it is low on oil pressure due to lots of wear and you are working it really hard with a camper on its back and a Jeep holding it back then it might have a rod bearing fail. But, if the oil pressure is reasonable then it isn't going to have a catastrophic failure w/o warning.

 

I should have mentioned the oil pressure is fine. The oil pump was even changed last year as a precaution when I changed the oil pan gasket. The pressure was good with the old pump, too.

 

My opinion, but I hope others will chime in, is that with good oil pressure you won't have a catastrophic failure. Especially since it has always been good. So, while you are surely down somewhat on compression and power, you should be fine for what you are doing.

 

Thanks, that's basically what I've been thinking. I'm interested to hear the opinion of others, too.

 

I drove my truck for a solid week,with a SERIOUS rod knock 22 miles each way because i had no choice. Believe me it will let you know . If it starts making noise,park it!

 

If you have good oil pressure and decent compression I wouldn't hesitate to take the truck on a road trip.

 

There are some that believe rods have so many cycles in them before they fail.

Think of it, how many times that rod holding a piston on top of it has to push it up, comes to a full stop then pull it back down to a full stop and do this all over again!
No one has come up with a set number just a thought.

BTW even a new motor car throw a rod. What if that rod had a defect that was not seen when it was put together. It then goes thru that start stop, start stop, etc and then BANG!

I think when it’s time it’s time and not much we/you can do about it.
Dave ----

 

Most rods fail from some sort of serious abuse, like a seized bearing, detonation, over-revving, etc. I'm doubting there will be a bearing problem when the oil pressure is good. And he's probably not experiencing pinging, much less detonation.

 

Um, thanks, I think. I guess that's strangely reassuring. On the other hand, it does make me wonder if I should live in a cave and never venture out, to be on the safe side...

 

Don't worry, it will give signs before something bad happens. If you keep an ear on things like I think you do(and like other non-car people don't) I think you would notice right away when things are going south and you can baby it after that and get home.

I had a 351w that was starting to give signs. It started to have a slight knock to it, only at brief times during hot weather and part throttle. It ran fine otherwise, but that was a sign to me that one of the bearings was getting a little bit loose and was something I listened for to get worse.

I had a 302 that started making a pounding noise, sounded like the exhaust was loose. I normally would have parked it till I figured out what was going on, but I was moving, pulling my junk cars on trailer trips and hauling junk and tools. Toward the end it sounded like someone was pounding on top of the cab when I had a pull on it. I kept driving it, had no choice. Finally I was pulling a hill and it suddenly got quiet. That was strange. After I got back home I went out and lifted the hood with it running, low and behold the crankshaft damper and pulley were wobbling around like crazy. My crankshaft had broken.

My next priority was to get it to the new house, we had to get out of the old house in a couple days. So I crossed my fingers and had my wife to follow me, and took off with it empty, hoping I would make it, the hew house was a hour away. Got 3 miles up the road and when I hit the brakes at a stop sign the engine quit. Got out and looked, the damper and pulley had been rubbing on the fan shroud, and it moved forward enough to bind the timing chain up.

How is that for running a engine to the very last gasp.

 

I'm in kind of a similar situation with my 5.8 f250 4x4 with abot 240,000 miles, and all original engine and engine management. It's a '90, and has an old '63 Alaskan camper on it. I take it to Mexico and Saline Valley in CA and other stupid places where if it breaks, I would have to be very creative to get the thing back to civilization.

I generally agree with the above, if you have kept up on the maintenance, and don't abuse it you'll be fine. I think of all the things that can go wrong, mechanical engine failure is pretty low on the list. Lots of other stuff can stop you first, so if the front end is reasonably tight, the brakes are good, the driveline is smooth and there are no leaks, I'd drive it anywhere!

 

Just make sure it's tuned. Check the timing and have a look at the plugs. I'd be nervous going long distance without knowing if the timing and carb are way out... and it sounds like a rattlesnake.

 

Define "good" oil pressure. 351's have "low" oil pressure from the get-go. and mine has had the oil needle on the "N" on "normal" for years.

Oil pressure is stronger as it warms up, but once up to temp is up to "normal," the oil pressure needle sits on the "N"

I was told years ago, 10lbs, 40lbs it does not matter, the heads are getting lubed ........

 

I would think its not the heads that get lube but the bearings!


Before they went to oiling thru push rods head oiling was thru a oil port to the rocker shafts. Do you know how many had this port plugged from bad/no oil changes and they ran for a long time?
Look at fords 292/312 v8 motors, they made a oil line kit to lube the heads.
How long will a motor run with no lube to the bearings?
Dave ----