Loud knocking noise

[briantedder]

I have a loud knocking noise in my engine. I removed the top left plastic that covers the timing belt, however I didn't remove the rest of the plastic cover. The belt felt tight, It couldn't be slapping at the bottom where I didnt' remove the cover, could it?

[amigo-2k]

With the cover removed run the engine and listen for the knock. The knocking sound is normally the timing belt tensor slapping around.

_Ryan

[rodeo02]

Originally Posted by briantedder

I have a loud knocking noise in my engine. I removed the top left plastic that covers the timing belt, however I didn't remove the rest of the plastic cover. The belt felt tight, It couldn't be slapping at the bottom where I didnt' remove the cover, could it?

Did you remove the right hand side T-belt cover too? Gotta get them both out of the way. The belt travels very close to the inside edges of the covers so any slack caused by a weak tensioner pusher will cause the belt to hit the cover. The "knock" should subside at higher RPM's (if it's a weak tensioner) does it do this for you??
G/luck!
Joel

[briantedder]

The belt feels tight, and I drove the vehicle down the road at around 2000rpm. It sounds like it is coming from the right side of the engine, the vibration is stronger there. I have 100 psi on one cylinder, it should be at a minimun of 128. I am going to rebuild. When I bought it, someone had a gallon of oil above the full mark!
I think they didn't check the oil, and it got to low and then they thought they could fix the problem by adding a lot of oil.

[amigo-2k]

If you're determined to rebuild it, first replace the timing belt tensor. Run it and see what happens. If the sound is still there, then by all means rip into it.

[rodeo02]

Brian- I'd definately tap a pressure gauge in somewhere & get an accurate (hot) oil pressure reading before I tore down this engine for a suspected rod bearing issue. Just for grins, did you run it (briefly) with the serpentine belt off, just to verify it's none of the belt driven accessories making the noise?
G/luck
Joel

[briantedder]

Yea, I took the serpentine belt off. The sound of the knock seems metallic. I am going to take the rest of the cover off of the timing belt, and if that doesn't make a difference, my dad and I will continue to dismantle. My dad is a machinist and we have to move his milling machine out of the way before putting the rodeo in the shop, that'll give me a few more days to think.

Brian.

[2eyefishclaw]

with the pass side timing cover removed start the eengine shine a light down in there if the timing belt looks sike its about to jump out of the engine like a bear busting out of a cage your tensioner is shot
something else to try is a screwdriver handle on your ear and the other end on the oil pan you should be able to tell if it from there that way
but as Ryan said oil pressure readings would be real good

[briantedder]

Took the entire timing belt cover off (3 pieces), including the drive belt, fan, power steering pump, water pump. Cranked the vehicle up, and it still knocks very loud. Must be a bearing.
Brian.

[2eyefishclaw]

its going to be a time consuming job
dont just throw bearings at it remove the crankshaft haev it checked out by a machine shop you trust # 1 journal may not be round anymore

[briantedder]

My dad is a machinist, and it is in a machine shop.

[briantedder]

We just finished the rebuild. The bearings on piston #1 were completely gone. Replaced the crankshaft, rings, main & rod bearings and one rod. Runs like a dream.

[rodeo02]

Originally Posted by briantedder

We just finished the rebuild. The bearings on piston #1 were completely gone. Replaced the crankshaft, rings, main & rod bearings and one rod. Runs like a dream.

SWEET! glad to hear you got thru it. How 'built' is the bottom end on the 3.2? A guy on a vehicross (3.5L) board had his apart & said that the 3.2/3.5 have 4 bolt mains and REAL stiff blocks any confirmation on this? Thanks for the info Brian. Hope the 'new' 'zu holds it's own for you.

G/luck
Joel