FJ40 Wedding Day Knock (1 Viewer)

[FJ502]

Hey fellow Mudders,

Wanted to get some advice and direction for my FJ40 situation.

Last Friday we trailered my cruiser out to NE Oregon to get married. Cruised around Joseph/ Enterprise just fine the night before. Day of, ladies took my red truck (to keep their hair nice) and the dudes rode in the 40. About 20 miles out of town a knock started in the cruiser. We pulled over, checked fluids (all good) and decided we'd forge on to Imnaha (tiny town in the middle of nowhere). Knocked louder until we made it into Imnaha, make a loud kapap sound and lost all it's coolant as we coasted into a parking spot along the bar. She did her job and got us there, and the incredible bar owner loaned us his truck and we made it up to the prairie for the ceremony.



Next day we recovered the 40, it fired up to get on the trailer and idles great but under load it knocks pretty good.

Tony at LCNW told me to pull the valve cover and I discovered some bent parts. Haven't heard back from Tony, but any guesses on what I'm looking at and what direction I need to go for repair/ rebuild/ replace?

I got my 40 when I was 15 years old and have kept it mostly stock, looking forward to your advice.

 

[John Smith]

Your push rods don't look bent to me in the picture. How did all the coolant exit the cooling system? Was it overheating before this event? Is the water pump locked up, or does it spin? I would start with draining the oil and see what you find. And congratulations on getting married!

 

[bikersmurf]

Really difficult to tell from that video clip.

Does it sound like a knock on a hollow door in sync with the engine RPM? Not as noticeable at idle, but gets louder as RPM goes up?


Check water pump spins… heck, even remove the belts and start it up for a minute. Anything different?


My first thought is a connecting rod bearing has spun. You’ll want to rule everything else out first. In ‘96 I spun a rod bearing and I was looking at $3000 to rebuild the motor… which was a lot when I was only making 10k a year. These days it’s way more. I’d find a good 2F before rebuilding one now.

Your young marriage might not handle the bills that’ll come with rebuilding a 2F. I’d look to swap in another and if you’re a glutton for punishment, rebuild your original at a later date.

 

[Living in the Past]

Would suggest pulling spark plugs wires one at a time and check for change in knock. Could go further and pull each spark plug one at a time so that cylinder has no load.

I agree nothing looked bend on the rockers just those pulling the valve open.

 

[Paul_A]

How did the coolant exit the engine? Crack in a hose? Water pump/t-stat housing? Overflow tank? Fan hit the radiator? Curious that the sound might not be in the engine but on the engine.

 

[FJ502]

Thank you for the replies! And sorry for the novice response to the rockers looking bent, the more you know(that they have knuckles that can bend!)

Not sure how the coolant exited the motor.

Latest Update: Took the rig down to LCNW and they diagnosed on the trailer. Listened to it for a second and could tell it was grim (loud knock from cam area).
Pulled oil filter, used a pneumatic hammer to open it(as to not introduce metal shards to evidence) and started to see shimmers in oil. Then pulled the paper filters apart and ran a magnet over them explaining steel in the filter would be very bad. Well, steel in the filter.



I’ve got a 1977 motor lined up to purchase in central Washington for $1000 and it comes with the transmission. Figured I will check the oil filter on that one to make sure it doesn’t have the same problem, but otherwise should be a fairly direct Replacement

 

[sogncab]

Don't scrap the old engine. Somebody can use it as a core or rebuild it themselves.

 

[Paul_A]

Well, at least it got you to the church on time. Swap out to the new motor, rebuild the old one for a spare and learn a whole lot in the process. If you're still married after all that you done good

 

[dmaddox]

My guess, sounds like a spun bearing - #2 always seems to go first for some reason - I've had two go on me. Sounds just like that. Drop the oil pan there will be a pile of shavings under one connecting rod or another.

As others have said, keep that motor (probably the motor it came with) and rebuild it later on. A fun experience.

Congrats on the wedding!

 

[FJ502]

Thank you guys, acquired new (to me) motor and will clear out the garage for my winter project. The previous owner wasn’t even home but had enough trust in a fellow cruiser owner and my wedding story that he instructed me into his garage to use his tractor and get it loaded. Paid the neighbor and off we went!

The numbers on the side of my current motor don’t exactly match the vin and I know the rig had a major restoration in 1992 (so maybe new motor?). Either way I’ll keep it for rebuilding or find a mud member that wants a project.

Happy to have an accommodating wife and new heart!