Engine Knock

Hey guys,
Been searching around on here to no avail. I have an 08 taco 4wd 4.0... I have been hearing a knock but only when the engine is warm and in gear (R or D). I was due for an oil change so I figured this was the issue...I just changed the oil last night and I am still having the problem. Any help would be greatly appreciated...thank you for your time and consideration

 

Not sure if this helps but the knock gets faster if in gear and let it roll on its own...sorry to bother yall I know there are a lot of "toyota tick" threads but this isn't the usual tick

 

Take a look at this thread: http://www.tacomaworld.com/forum/technical-chat/356603-knocking-sound-not-famous-tick.html

Might be what you're experiencing, might not. If not, a sound clip of your problem would be helpful.

 

Mooze,
Thanks for the reply...mine only does it when in drive or reverse. Similar sounds though...anyone else have any suggestions?

 

Might be a gas issue... Some of the 1gr v-6 engines develop a taste for 91+ octane fuel

 

LMAO, truth

 

I will try a fill up as well tomorrow...thanks for the replies...keep them coming

 

bump for the night

 

You need to post more. When does it Knock driving around? Putting it in gear? Putting it in 4x4?

 

The engine knocks when the engine is warm and in gear while sitting still...once you accelerate and begin to press the throttle the noise can not be heard...haven't notice any difference whether the A/C or heat is on...have not tried putting it in 4wd

 

Does the noise do it at all when the truck is rolling? Any noise when starting on a corner, like at a stop sign? If so, could be a motor mount. Just an idea since there isn't much detail posted.

 

I wouldn't worry about it I mean if you can't hear it when your actually driving or popping your hood and reveving it up. I'm not saying there isn't something there but its not bad enough to do anything about.

Could be a lot of things hard to say without more information but from what you told me your motor should be ok. Its probably the tranny, there is a bearing in auto's that will spin while your stopped sounds like its pitting but it could be something else just my 2 cents.

If you can get some where with a lift get it up in the air while someone is in it and put it in drive have them step on and off the breaks you might be able to hear it that way. Use a nice big screwdriver put your ear to the plastic end and the metal to the trany see if you can hear it.

 

58 Siesta,
If the truck is in gear and I let it roll in drive or reverse on its own the knocking becomes faster. Not sure what the heck is going on...I will try an upload a recording of the sound this afternoon.

 

Check your CV joints.

 

Here is a vid of the sound it's making I did last night...hope this helps

http://youtu.be/6rI0LdY72I8

 

Have someone sit in the Truck with the parking brake on and their foot on the brake in gear. This way you can trace the noise down. It does not sound like an engine knock. It could be something stupid like an exhaust rattle from a cracked weld for example. I was a master tech for Toyota until 4 years ago and have only seen one of these engines tore down. The only reason that one was done is because it was sent out with no oil from an oil change place. The only thing we had to do quite often was remove the upper plenum to replace the Knock sensor pigtails harness from being chewed by field mice or rats. They must be awful tasty to them. LOL! They are practically bulletproof. I never even seen a transmission having to be repaired on one. Was the AC compressor on when at idle and does the noise change when it cycles? I would take it to the dealership or stealership as some call it. They will probably diagnose it in less than 10 minutes. It is hard to diagnose from a video clip.

 

that should be pretty easy to track down have you got it up on a rack yet?

 

I haven't gotten it on a lift...i can get some help this weekend to check it out some more...if it is the knock sensor is there any harm in driving it?

 

I didn't imply that it was the knock sensor. I was just stating that was about as far as those engine were ever needing to be torn down to in my years working on them. I would be willing to bet it is gonna be something stupid. Again I would take it to the dealership unless you are mechanically inclined.