Rod Knock or Exhaust Leak or something else...

[LS1FJ40]

1993 FZJ80 335k miles

She has purred like a kitten for the past 23k miles since I got her. Yesterday the low oil light came on (she burns a fair amount, no leaks). I dumped a couple of quarts of Delo 15w-40 in and drove on.

Today I pulled on the interstate and heard the noise below. I was on my way to an appointment so I said FAWK it and drove it about 150 miles.

Ideas? Thoughts?

 

[Red Merle]

The cadence of the sound makes me think valve something. I have used a mechanics stethoscope to listen to to the top end of mine since I had the head all done over. I don't think the crank turns that fast, but I could be wrong. Maybe valve seals? You are burning a lot of oil.

 

[AMX390]

Good thing you have spare Land Cruisers!

 

[LS1FJ40]

I'm leaning towards exhaust leak. Possibly where I deleted the PAIR system...

 

[Red Merle]

I'm leaning towards exhaust leak. Possibly where I deleted the PAIR system...

That is all above my pay grade. I keep all of that stuff in there because it seems to work and I am not sure I am ready to go "off the grid" yet when it comes to monkeying around with stuff.

 

[LS1FJ40]

That is all above my pay grade. I keep all of that stuff in there because it seems to work and I am not sure I am ready to go "off the grid" yet when it comes to monkeying around with stuff.

There are two bungs on the side of the exhaust manifold where the PAIR system attaches. I'm thinking one of those is leaking. Or an O2 sensor bung.

I'm crossing my fingers...

 

[Red Merle]

There are two bungs on the side of the exhaust manifold where the PAIR system attaches. I'm thinking one of those is leaking. Or an O2 sensor bung.

I'm crossing my fingers...

I actually do know where those are. So did you just cap them, or what?

 

[4G63 POWER]

Rod knock for sure. Why are you running 15w40 in the winter????????????

 

[LS1FJ40]

Rod knock for sure. Why are you running 15w40 in the winter????????????

I was running 5w-30. Didn't have any. It's 60 degrees out so I dumped 2 quarts of 15w-40 in so I wasn't running low.

 

[SmokingRocks]

The viscosity isn't the issue. You have some serious tappet knock

 

[LS1FJ40]

The viscosity isn't the issue. You have some serious tappet knock

What is tappet knock?

 

[gsi18867]

Did the low oil light come on while you were going uphill?

 

[LS1FJ40]

Did the low oil light come on while you were going uphill?

Nope. Flat ground. Pulled her over and gave her a couple quarts. And when I say "a couple of quarts" I'm guessing. I was filling it from a gallon. IIRC the low oil light comes on at 5 quarts.

 

[Andrew Bluemel]

Sounds just like my 60 did just louder. I adjusted the valves and now it's gone.

 

[LS1FJ40]

Sounds just like my 60 did just louder. I adjusted the valves and now it's gone.

Good ear!

Just left the muffler shop. We lifted it up. No echo at the pan. Doesn't sound like it's coming from the bottom end. Exhaust is tight, no leaks. My buddy there (not a Land Cruiser mechanic by any means) thinks it's lifter/rocker related.

"Dude, it's got 335k time for some maintenance!"

Never adjusted the valves on a 1FZ-FE. Is it difficult?

Can the rockers be adjusted?

I'm a mechanic...

Also noticed fresh oil leaking at the bottom front of the motor. What could that be? I've replaced the oil pump cover and crankshaft seal. Is there another seal down there?

 

[Milkm4n]

I had a similar knock, started out of the blue and I was sure it was rod knock. Ended up being a shot ac compressor bearing....thing is once you hear that knock coming from the compressor it's usually too late to just replace the bearing. I have a brand new Toyota compressor clutch kit with shims but it was too late had to buy a new compressor. Check your ac compressor if it is the culprit remove the belt.

 

[missouriman]

Mine just started the same sound, not quite as bad but it is there. Started out of no where. Please let me know what you find.
These motors are expensive to rebuild.

 

[nukegoat]

Good ear!

Just left the muffler shop. We lifted it up. No echo at the pan. Doesn't sound like it's coming from the bottom end. Exhaust is tight, no leaks. My buddy there (not a Land Cruiser mechanic by any means) thinks it's lifter/rocker related.

"Dude, it's got 335k time for some maintenance!"

Never adjusted the valves on a 1FZ-FE. Is it difficult?

Can the rockers be adjusted?

I'm a mechanic...

Also noticed fresh oil leaking at the bottom front of the motor. What could that be? I've replaced the oil pump cover and crankshaft seal. Is there another seal down there?

Distributor o ring dry?

 

[nukegoat]

And bro welcome to owning a cruiser. Enjoy the sickness. Some of us have been dealing with oil leaks for years! Let us know if we can help a newbie like you with anything else

 

[NLXTACY]

Get yourself a mechanic's stethoscope. It helps, a LOT! Just recently I was able to pinpoint my bad fuel injector issue.