Fj40 weird engine noise. (1 Viewer)

[Rusty72cruiser]

Hello, I have been on this site researchingfor awhile now and decided to now join. Anyway I recently bought a 1972 fj40 for a project and hopefully restore. Im usually good with engine work but this noise has me stumped doesn't sound like rod bearings or anything from the bottom end also not like a valve tap eventhough I will be adjusting them soon. A friend thinks it's the cam moving front to back. Has anyone heard of this? Or this noise in general? I have also noticed white smoke from the valve cover, I pulled the cover to and noticed these rockers have something on them might be just rust but only the last set has it.
Thanks, Ross

Video of noise


Video of valves/smoke

 

[78fj40mg]

Ross, It sounds like a crank shaft bearing noise than a valve noise, or perhaps the crank and/or the cam shaft have excess lateral movement. Interesting issue must do some research on it.

Welcome to MUD!

 

[reddingcruiser]

Rod knock?? Piston slap?? Those were my first thoughts. Doesn't sound like valve train noise, at least not with my low quality computer speaker.

 

[reddingcruiser]

Piston issues might explain the smoke in the crankcase.

 

[Rusty72cruiser]

I'm hoping it's not from the bottom end since I was planning on putting money into the body and such not the motor. It doesn't sound like a metal on metal knocking noise more of a popping kinda thing if that makes sense. Like I said I've never heard this type noise over years of working as a mechanic, but this is my first straight 6 motor I'm getting into so I could be wrong.

 

[Rusty72cruiser]

Piston issues might explain the smoke in the crankcase.

I plan on pressure testing the cylinders when I get my hands on the gauge from work

 

[reddingcruiser]

I was just going to suggest a compression test.

 

[Rusty72cruiser]

So much for body and brake work only, the learning experience begins haha. I will definitely do the compression test and read up in my service manual on checking the cam specs.

 

[CarDude]

I bad a similar noise and it turned out to be the oil slinger in the timing gear assembly.

 

[Rusty72cruiser]

I bad a similar noise and it turned out to be the oil slinger in the timing gear assembly.

That's interesting I'll have to pull my cover, was it not feeding oil and just needed that piece replaced? And was your noise only from the front of the block or front and back?

 

[lostmarbles]

Sounds like a bottom-end knock to me. (First video)

(and probably a big-end bearing)

 

[CarDude]

That's interesting I'll have to pull my cover, was it not feeding oil and just needed that piece replaced? And was your noise only from the front of the block or front and back?

It was from the front and at first it was kind of a knock them turned into a sound that resembles a card in the spokes of a bicycle wheel.I think the harmonic balancer was not installed correctly. The balancer holds the slinger against the crank gear.I think the slinger was just spinning freely and the stress and vibration tore it apart.

 

[shelfboy1]

is the oil pressure low ? that usally happens when you have a bearing problem .at an idle the noise inside the tin valve cover can sound like a rod .make sure the valves are adjusted right and eliminate that problem then go to the next one .dumb question but did you check the oil they take 8 quarts and i have seen to many 5 quart oil changes over the years almost sounds like the oil pan is empty good luck

 

[Steamer]

In the first video at idle I'm counting about 4 taps per second or 240 per minute. I'd say that relates to every other crank revolution. So it could be cam or valve train related. But then it could also be piston related just on the power stroke. Also the dizzy & fuel pump operate at half the speed of the crank. Just thinking out loud.

 

[Weber Sarge]

With the valve cover off , spin the push rods a bit and see if any are bent . Also , check the distributor shaft for up/down play...
Sarge

 

[Rusty72cruiser]

I did just change the oil with a full 8 quarts so I know I'm good there. If I do eliminate the other problems such as valves would you guys suggest rebuilding the F motor in it or finding a 2F motor to put in? Alot of people seem to do that. Or save for a toyota diesel haha.

 

[uae1020]

I did just change the oil with a full 8 quarts so I know I'm good there. If I do eliminate the other problems such as valves would you guys suggest rebuilding the F motor in it or finding a 2F motor to put in? Alot of people seem to do that. Or save for a toyota diesel haha.

Hi did you find out what is the problem. I have the same noise in my Fj40 1983