Is this a Rod knock?? (2 Viewers)

[jhennessy]

Can anyone tell me if this is a rod knock? Video quality is bad but you should be able to hear it ok. It gets louder from about 900-1500 RPM and then goes away in higher revs.

YouTube - VID 00034 20110415 1605

Thanks in advance for all of your opinions.

 

[guzzla]

Mate, that does not sound good at all. I'd be getting it looked at my a good mechanic to be sure and I'd be getting it towed there just to be sure.

 

[Kernal]

What model, engine, miles, symptoms (white/blue smoke, coolant in oil)? Can you post a longer clip in daylight (I can hear better when I can see what I'm lookin at ).

 

[jhennessy]

Its a 97 fj with 140k. Has zero problems besides the noise. It drives normal, is quiet at highway speeds, no smoke, no oil leaks, no codes. To give you a better visual on the "video" I had my blackberry inside the bay to the right of the block, so it sound much louder than it does if you are just standing over the engine.

I'll try to take a better video after dinner. Thanks-

 

[Kernal]

Some people have used a section of hose and held one end near different components and the other end to their ear to narrow down where the noise is coming from (be careful you don't stick your hand into a fan belt or pulley). Is it louder when you start the engine cold. To my ear sounds like at least three different noises: maybe an exhaust leak along with some valve train and belt/pulley noises??

 

[jlm43]

I am no expert but I have been told that if it is a rod knock, it will not go away. You may not hear it at low RPM's, but it only gets worse with higher RPM's. I have something similar that recently started with mine. The local opinion is that the valve train is starting to make more noise than just the usually start up tick.

 

[BrotherRob]

The frequency changes with the RPMs, that would mean something that moves at or near engine speed. The first thing I would check is everything driven by the belts, including ac, alt, PS and idler bearings. Turn the fan and see if it moves freely or is hitting something. The other thought would be a stuck timing chain tensioner which would cause the chain to slap against the cover.

It does sound like a rod knock, but at 140k, that shouldn't be an issue unless it's been abused. I agree you probably shouldn't drive it until you can assess it thoroughly.

 

[jhennessy]

Since my wife is a nurse, I "borrowed" her stethascope and i seemed to hear the noise most concentrated around the AC compressor. The top end sounded quiet across the length of the engine, the water pump also sounded quiet. Where is the timing chain tensioner? I'd like to listen around that area too.

Its also running non-toyo belts which my mechanic has recomended changing.

 

[BrotherRob]

Since my wife is a nurse, I "borrowed" her stethascope and i seemed to hear the noise most concentrated around the AC compressor. The top end sounded quiet across the length of the engine, the water pump also sounded quiet. Where is the timing chain tensioner? I'd like to listen around that area too.

Its also running non-toyo belts which my mechanic has recomended changing.

IIRC, the chain tensioner is on the PS of the cylinder head. If it's stuck, you're likely to hear noise anywhere on the timing cover.

The ac compressor makes a lot of sense, if it's making noise, you might want to pay it some attention.

 

[jhennessy]

Would the AC clutch make that loud of a noise? It gets somewhat better when i turn on the AC but doesnt go away completely...I guess I can try taking off the AC belt.

 

[BrotherRob]

I've not experienced ac problems on mine so I'm not the best guy to ask, but anything driven by the belts can make a bunch of racket when they start to go bad.

 

[kerrye]

It mimics the pattern of a rod knock. It's quiet at idle then gets progressively louder with rpm's. But it doesn't seem metallic enough to be a rod knock to me. If there was a history of running the engine out of oil I might think it was a rod knock. But without something like that, I'd look elsewhere. Starting by removing the AC belt is a good idea in my view.

 

[jhennessy]

Update: Changed all accessory belts with OEM ones. Noise is gone. Thanks!

 

[CarlSeattle]

I suspect anyone viewing this thread is also, like me, concerned about rod knock from their Cruiser. Therefore I will post a few observations that might help.

1. Try to identify the exact source of the noise. "Rod knock" apparently can actually be a result of loose or leaky exhaust/EGR components. Apparently also if the AC compressor has issues. If engine internals it could be piston slap or stuck timing chain tensioner. Some owners feel it's a benign noise that can be ignored, likely due to hydraulic chain tensioners.

2. Before planning any kind of teardown, change the oil and see if that affects the noise. Also have the oil analysed. $30 through the mail with Blackstone Free Test Kits | Blackstone Laboratories

3. If your Cruiser knocks only at cold startup (like mine), it's likely due to low oil pressure. There are a couple options. This thread has some good discussion from mechanics 1FZ cold start engine knock...whose got it?

4. Oil + filter upgrades. There are a million threads on ih8mud about oil. fj80toyman reported quieting his knock-on-cold-startup by upgrading oil & filter to NAPA 1515 filter and Mobil 5000 non-syn 5W-30, + 1 quart Lucas synthetic additive. FXR UPR reports better results using 5w30 over 15w40. (He also replaced the chain tensioner, which quieted things)

5. Engine Internals. If you have to tear into her, it's wise to start with the cheapest, most likely culprits. Some owners report improvements by replacing their chain tensioner. Replacing the main bearings is relatively cheap.

I have PMed other FJZ80 owners reporting cold-start knock. Will update this list as responses come in.