Hi everyone,

So since my last oil change I've had a knock/tick that's occured in the engine for a brief moment at startup then subsided. Again this didn't happen at all until immediately after my last oil change. I was a bit taken aback by it, but it's an old truck and so I just put it down to lifter noise until the oil pump started going.

Fast forward to today, where upon leaving work I started up my truck and the knock lasted an unusually long time. I didn't think too much of it until it popped up on my drive home. I pulled over to take a look and found it to be coming from the heads, checked the oil and saw it was frighteningly low contrary to what my oil gauge read, and shut the engine off. I started it back up and again, the gauge read normal, so I figured the dip stick was just conservative with respect to oil level, and revved the engine a bit. The knock went away and I drove home. The knock came back after another 10 minutes or so of driving and prompted me to stop and pick up some oil before heading home. I topped the oil up and the knock changed to where there was no more knock or tick at idle, but now I have a rather intense knock at 1000+ rpm. My concern is that I ran the engine with lower oil than I thought and that I've done damage to bearings. I've got some videos that I'll post momentarily.

If you guys could give my your best guess as to what I should do I'd really appreciate it.

I'm worried it may need a rebuild at this point, in which case I'll have to get a new daily driver... Either way let me know what you guys think.

Thanks,

Ray

 

Here is a video where you can hear the knock...

https://youtu.be/H_gg2YaR77Q

And here's another video with the RPM gauge to give you an idea of where it's occuring

https://youtu.be/xRJca1PnLn4

 

"checked the oil and saw it was frighteningly low contrary to what my oil gauge read, and shut the engine off"

the way i read this, you are checking oil with the engine running, which will give a false reading.

 

Oil pressure (the gauge) may read normal as long as the pick up screen in the sump is covered. You could be 3 quarts low, and under some conditions, like when the engine is cold/cool, still get normal oil pressure.

It may see obvious to many, but your statement does suggest you checked the oil with the engine running. The engine must be off for a few minutes and the truck parked on level ground to get a proper dipstick reading.

Anyway. It sounds like a rod bearing to me. You can isolate which cylinder it is by pulling the plug wires. The drill is this so you don't get a jolt:

Remove a wire, start engine and rev like you did. If no difference, shut it down, re-connect that wire and pull the next one, then re-start and so on. When you find your bad one, the noise will go away since that piston/rod assembly is just floating along with no ignition to power it. You can do this at the distributor if you can trace the wire if it's any easier.

This can't be fixed with just pulling the pan and fitting a new bearing to the connecting rod. either. The journal gets egg-shaped from the pounding and then it's time to grind the crank if it can be saved. Engine has to come out. Sorry.

 

You should rebuild, but if its going to be a while, throw in a full synthetic 10w30.

 

The oil gauge is pressure gauge not a level gauge first off, two separate things. Second engine has to be off for you to check oil level, on Fords you don't usually have to let it sit, you can check them pretty close to right after shutting it off. From the video it sounds to be a rod bearing, you need a motor brotha

 

Thanks for the replies guys. Yeah as you mentioned, I'm an idiot and checked my oil while it was running, so my reading was completely un reliable... My main point on the oil gauge was that there was a reading to indicate that it wasn't excessively low on oil which was my major concern.

The knock has subsided again after doing an oil change, but still pops up momentarily at startup then goes away after less than a second. At the time of the video the knock was consistent. You guys are probably right in that it's a rod bearings that's on its way out, but given that it's intermittent I'm gonna drive the truck still while I get a more fuel efficient daily driver lined up.When that happens then I'll take the time to do a rebuild and clean the truck up.In the mean time I'll just keep a closer eye on my fluids.

 

Not using a Fram filter are you?

 

Yeah, a fram synthetic. Think that may have something to do with it?

 

Using the "Orange Can of Death" I see... And they sold you on the "Synthetic" hype.

Ford and Dodge/Mopar guys only run Motorcraft and Wix filters. I even ran Motorcraft FL-1A filters on my '04 Hemi. Hell, I wouldn't use​ Fram on my riding mower. Only Chevy guys ,with BIG ego's, run Fram filters.

 

Although I use a Motorcraft FL-1A on my 351 in the F250 and on the 292 in my '56, I doubt that the use of a Fram oil filter caused this. Funny (?) though that the knock started after the oil change....odd. You may as well drive it like this until you get it together to fix it. Won't make much difference at this point. Put some of that motor honey stuff in there...

 

Lucas oil stabilizer is your friend. Lots of it.

And save for a rebuild, you have a bad rod bearing. run it too long with the knock active (i.e. audible), and you'll need a crank and rods too.

 

was this the first time you've changed the oil?

there is a good chance the previous owner had thicker oil or additives in it to quiet it down

 

I am still stumped by this statement. What reading would tell you that it is low on oil? It is a pressure reading not a quantity gauge.

The knock is there at startup because the filter is allowing oil to drain back out of it overnight causing a dry start until the filter is refilled.

 

Just as a side not, so fram filters are defiantly no good? Ive got one on my pontiac but on my Ford and Chrysler Ive got wix and next change have a motorcraft there ready to go for the Ford.