So I was driving back to Maryland after putting some work into this truck. Its a 92 F-150 with a 302. The exhaust is pretty raspy. Im about 35 miles from where i needed to be and I heard a slight ticking, wasnt positive if it was the exhaust or not. So I kept going. Happen to look down at the gauges and noticed the temp was goin up a little. Right about that time I seen the oil pressure was bottomed out. Instead of stopping right there I pushed on wanting to get home. 10 miles later the ticking turned to knocking and I pulled off on the side of the road and got it towed. My question is how bad did i mess up the engine? If I replace the oil pump will the engine still run? I know its gonna need a rebuild but is it possible to get a couple months out of it?

 

Hard to say how bad the damage is. My guess is if you heard real knocking its just a time bomb waiting to go off. You could blow it up the next time you start it or you could get 500 miles out of it.

 

yea thats what i figured

 

Not good. Rebuild time, at least for crank and rod bearings. Who knows, on the cheap new rings, rehone, and bearings may last a while longer...all depends on the interior condition and wear of the motor. I did that to a Tahoe at 176k miles and 3 years later it's still running strong.

How many miles on the motor?

 

i was told it only had 18,000 after they rebuilt it, but apparently they didnt replace the pump. So what r u saying i should rebuild.

 

lol..

So next time your engine starts making noise as your oil pressure drops, I recommend turning off the engine and pulling over.

 

...you not only have issues, I think you have the whole subscription. Sounds like the engine gave up the ghost. Does it still crank?
Roger

 

If it's knocking, drop the exhaust, the pan and get to the mains. Check the rod bearings. You may find that before you pull the pan, you can get a visual simply by draining the oil. If there is metal debris, rebuild. If not, it may be a rod that has spun the bearing and is ready to throw.

I'm inclined to say start with visual, then go from there. Sorry to hear it's banging. Let us know what you find.

 

You now have permanently installed the famous Ford "death rattle" in the truck, and sorry to say, but odds are you have wiped a rod bearing or two as well as probably taking out some main bearings also. When you shut it down was it just knocking or was it vibrating also? If it was just knock, its probably just the rods, if it was vibrating too, then count on a main or two gone, and a good chance that the block may be toast as well. Sorry to have to say that. Either way the motor is going to have to come out and then pull the main caps and rod caps and hope for the best (that its just a rod, and you can *maybe* get the crank turned and replace the bad rod.) Keep in mind you will also (assuming the block is good) need to clean all the oil galleys out, as there will be metal shavings all thru them now.

 

All the above posts make sense to me. Both my trucks are very high miles, so have been fortunate. Good o'l fashioned proper care has worked.

 

Well tomorrow morning I will be bringing it into the shop to drop the oil pan. I should be able to replace the rod bearings without pullin the engine right? As far as the vibration I am not positive. But it never got close to overheating and it does start back up

 

You can replace the rod bearings without pulling the engine. But it's almost a sure bet that the crankshaft journal on the rod that is knocking will be bugared up. I would expect very limited, if any, service out of the engine doing this. Sorry.

 

well im hopin it will give me a couple months to save for a complete rebuild

 

Yeah, I'm very interested in what the mains and the rod bearings look like. Could be a quick way to make a "make it or break it" diagnosis.

Let us know what you find!

 

The vibration would probably not be noticable at idle or lower revs, but if you try and drive it, it would start vibrating like crazy once it had a load against it. If thats the case, you can count on a main bearing being gone and the block most likely toast. If its not vibrating you may still have a bad main, but not have ruined the block.



Exactly, whichever journal has spun the bearing will have bits and pieces of bearing now embedded in the journal surface, in addition to the grooving of the bearing surface. The amount that the crank would need turned is usually well beyond safe tolerances for machining, so the crank is most likely toast. Also, if its just a rod, depending on how hard it started banging, the rod end can egg shape out, giving you a rod that is not going to hold a bearing very long either before it spins out again, possibly having catastrophic failure this time and sending a rod thru the side of the block. There are some bandaid tricks that can be done (polish the journal with emery cloth as best you can, and seat the bearings with locktite into the rod and block) but those are only for something you are wanting to last a VERY short while without putting a bunch of money into (think demo derby car) and not something to do and expect to be able to drive it one the street again.