FZJ80 Knocking

[gabew]

Hello! I recently became the owner of a 1996 Land Cruiser with 230k on the clock. It runs and drives really well, but I've noticed it has a knocking sound coming from the engine. At first I thought it might be valve clatter, but I'm concerned it might be something more serious. It had the sound when I bought it and it didn’t get any worse after I drove it 130 miles home. Oil pressure seems fine, at hot idle it's at the lower middle line on the gauge and stays around the upper middle line while driving. I tried to test for rod knock by removing each of the spark plug wires one at a time with the engine running listening to hear if the knocking quieted, but it didn't. I have a video of the engine running . Does it sound like rod knock? Or could it be something else like detonation?

 

[Red Merle]

I can hear the knocking sound, but it also sounds like you have exhaust issues.

 

[gabew]

Yeah, I noticed it sounds like there’s an exhaust leak somewhere near or in the engine bay. Could the two be related?

 

[Red Merle]

Yeah, I noticed it sounds like there’s an exhaust leak somewhere near or in the engine bay. Could the two be related?

Maybe. If something is rattling or it has a hole in it, that could cause a sound like that.

 

[gabew]

I took off the heat shields and inspected the manifold and pipes up to where they connect to the cat and didn't see any cracks or holes. I wonder if the manifold gasket be the problem, the valve cover leaks a bit and there's some buildup around where the manifold meets the head so maybe that oil ruined the gasket.

 

[slow95z]

well i would start with sending in an oil sample to blackstone. if its a rod knock they will see metal in the sample.

the most common places to get a knock are the power steering gear being put on wrong or exhaust.

 

[80proof]

My belts that looked fine but made noise similar to that. Replacing them fixed it.

 

[gabew]

well i would start with sending in an oil sample to blackstone. if its a rod knock they will see metal in the sample.

the most common places to get a knock are the power steering gear being put on wrong or exhaust.

Ok, I ordered a sample kit from Blackstone, said it should get here in 1-2 weeks.

My belts that looked fine but made noise similar to that. Replacing them fixed it.

I noticed that my belts looked somewhat sketchy, so I'll do this as well. The noise seems to be more pronounced towards the front of the engine so it's definitely a possibility!

 

[80proof]

I thought I had a failing waterpump bearing or something. Turned out just my belts! Toyota belts are cheap, like $20 for both. GL!

 

[gabew]

Well I changed the belts (which were really cracked) but the knocking sound persists. Guess I'll try not to drive it too much until I can send the sample into blackstone and see if there's any metal in the oil.

 

[slow95z]

Take the power steering pump off and crank it up. Only for a few seconds but see if your knock goes away.

 

[BILT4ME]

When you had your belts off, did you spin your idler pulleys by hand to see if they felt rough or wobbly?

 

[80proof]

When you had your belts off, did you spin your idler pulleys by hand to see if they felt rough or wobbly?

I actually remove the "idler" pulley that is on the DS of the block. I took my tensioner out, cleaned and repacked it. The belts were my culprit. Obviously check all pulleys and bearings while you have them off.

 

[gabew]

I found it! I followed slow95z's advice and took off the PS pump and cranked it up; it ran as quiet as a mouse! Looks like I'll be ordering a new pump and gear. Thanks guys for all the help!

 

[slow95z]

I have a few good used ones if you want to save some cash. The pump isn't your issue, it's the gear. That isn't supplied at the local parts store.

 

[MudSlider80]

I have a few good used ones if you want to save some cash. The pump isn't your issue, it's the gear. That isn't supplied at the local parts store.

Do you still have extra gears? I’m experiencing the same issue

 

[slow95z]

Do you still have extra gears? I’m experiencing the same issue

I do but it's not cheap. Send me a private message