Strange Knocking... - Toyota Nation Forum : Toyota Car and Truck Forums

WreckedCamry · 12-26-2005, 04:19 AM

My '96 has the 5S-FE (I4) with a knock on Cylinder #1. The EEC said the knock sensor was bad for 4 months. I never heard a knock so I kept driving. Just recently,Within two days' it went from the usual to knocking. If you pull the spark plug boot,It quits knocking. It just runs off the 3 cylinder. Re-connect the boot and it resumes knocking. Could it be the spark plug? Crankshaft problem? Wrist pin? Exhaust valve stuck shut?
Sorry for this to be my second post,But I never had any problems 'till now.

Thanks.

luisitol · 12-26-2005, 05:40 AM

Ok well it can't be rod knock or the pistion hitting the cylinder walls because the woudl happen regardless of whether eor not you have the aprk plug boot in there or not. I would first check your spark plug (make sure it’s not loose) and make sure you are getting appropriate spark. Come back if that doesnt work

lalo · 12-26-2005, 07:07 AM

Maybe check your timing, the knock sensor is there to Advance-Retire your timing so you dont hear knocking. IF it was bad then the timing might have been advanced too much, or retired too much and so you hear knocking now because the cylinder is not detonating at the correct time.
Edit: (most engine knock is there, to some small degree. People just dont feel the vibration until it gets excessive.)

WreckedCamry · 12-26-2005, 03:28 PM

The knock is coming from the lower half of the engine......Like a wrist pin or bearing....At Idle it don't really knock. Its when you get on the throttle it knocks. Could it be the timing belt? Spark plug looks good. It has them Bosch platnums,Same for the wires. I replaced the knock sensor,still does it.

BlueFusion6851 · 12-26-2005, 03:32 PM

First problem is the Bosch plugs. Swap for Denso plugs or the like. (i forget the name)

WreckedCamry · 12-26-2005, 03:38 PM

Lol,Whats wrong with Bosch plugs? I know the plugs with dual contacts are a rip off. Could It be carbon build up? Just throwing ideas out there. Do you all think a can of sea foam would clear it up?

Gary_602Z · 12-26-2005, 09:08 PM

Lower engine knock? Sure sounds like a rod bearing or wrist pin bearing. Yes it can go away when you take pressure off the cylinder (which you are doing by by taking the wire off the spark plug)

Gary

WreckedCamry · 12-26-2005, 09:33 PM

I drained and strained the oil and there isn't any metal shavings in it,So I'm hoping it isnt a bearing. I've been told if it's a wrist pin,I can replace it just by dropping the oil pan.
I'm a newb with foriegn cars,I'm used to older domestic cars.
Thanks for the help.

88 LE · 12-26-2005, 09:59 PM

Quote:

Originally Posted by WreckedCamry

I've been told if it's a wrist pin,I can replace it just by dropping the oil pan.

Nope. Even with the oil pan removed, the crank is in the way.

1. Remove the cylinder head and knock the piston + rod out the top of the block.

or

2. Tear the entire engine apart.

WreckedCamry · 12-26-2005, 10:19 PM

Is there a "tutorial" online how to do this? I have a chiltons,but it isn't too good. Thanks guys.

88 LE · 12-27-2005, 02:10 AM

^ See link below to download the factory (Toyota) service manual.

http://www.toyotanation.com/forum/t62501.html

WreckedCamry · 12-27-2005, 02:23 AM

Thanks for the link 88.

I pulled the oil pan and its not a wrist pin....It's the rod bearing.....lot of shavings in the pan......and the rod has plenty of slack on the Crankshaft....

WreckedCamry · 12-27-2005, 07:47 PM

Bump

WreckedCamry · 01-24-2006, 03:55 PM

Got the bearings replaced and fired it up yesterday,
Runs perfect now.

Gary_602Z · 01-24-2006, 04:40 PM

Great! Knew it had to be a wrist pin or crank bearing.

Gary