This is actually not that uncommon. The pulley is actually 2 seperate parts bonded together with rubber. Over time the rubber dries out cracks and eventually seperates. I personally wouldn't be driving it with the pulley like that.

AC Compressor is fine. Idler pulley is seized

Sooo, I am gonna swap over the crank case pulley assembly, and put everything together, except for the AC crap :/

Calling ABC now to see how much a new pulley goes for.

quote:

Originally posted by Sand Bag:Calling ABC now to see how much a new pulley goes for.

les than ten bucks for the bearing
http://nissan4wheelers.com/eve/forums/a/tpc/f/376607843...10939011#96210939011

Easy fix.

Already ordered a new assembly

I will have to do this to my current one anyway, and save it as a trail spare

I am done. Got the new crankshaft pulley installed, new belts on, and I am rockin out.

I am working on a write up w/ pics, so look for that soon.

quote:

Originally posted by Reserector:
Good point, Datz. Come to think of it, how is the idler pully?

Damaged Idler Pulley bearing:


Damaged Crankshaft Pulley Assembly:


New pulley installed. I think I am gonna have to do the timing chain mod... you can hear it slapping around in there:
New Pulley installed

What is the timing chain "mod"?

you need a new chain?

There's an adjuster or guide or something in there that gets worn, and it lets the chain slap around. I guess it's just a trait these motors have.

It doesn't just slap a little at startup and go away after oil pressure comes up- it slaps all the time?

Wasssa mileage on thta puppy?

not as much as yours... about 170k.

Slapping comes and goes.

Maybe it's an oil pump issue... But it sounds like you'll have to go back in, pull that pulley, and the head too. YOu tried seafoam in the oil trick right before an oil filter change?

There's a main chain, and another that takes that power to drive the cams. CAn't really explain it off the top of my head, but when you look in the FSM ,the picture becomes more clear.

ANd it clearly states the head must come off to do the deed.

not the easiest TC to swap out.

POssibly all DOHC motors are like that?

Not all, but a lot of them

I can check Alldata in a few minutes. You might be able to get around having to remove the head.

The 4.0 V8 in the Jag XKS and XJ have a similar problem, but the guides would fail, the chains would screw up, then the cams would break, then half the valves would get bent. I've done a few of these in the past year. One failed at 75k miles...

SomeData didn't have much to say. There are 2 chains, and 2 tensioners. The tensioners and guides look like they can be replaced without removing the chain. The tensioners are the type with a grenade pin, so if they are still working properly you'll have to remove them and put them in a bench vice and insert a suitable pin, then reinstall and remove the pin. It takes the guesswork out I guess.

Somehow a chain replacement requires removing the head. It didn't say why and the pictures sucked. Nobody at the shop has ever had to go that deep into a KA. I only know 2 people who have killed one: Andy and my friend who ran one with no oil...

I would take all the crap off the front of the engine and look around. It almost sounds like one of the tensioners is acting up, or one of the guides is worn out, from what you described.

edit: just read the thread again, and it appears that you already knew this

I did the chain mod on the KA24de in my Altima. Pull the valve cover and you will see the two chain guides on the top & exhaust side of the chain that drives the cams. Those can both be removed. THere is a TSB about this from Nissan. They determined that those guides are not needed and are the source of the noise. My altima sounded like a can of marbles before.. it is silent now.

To remove the exhaust side guide, you will need to pull the front upper timing cover. Not too bad of a project, but it will take a good solid evening to do it and then get everything sealed back up and together.

Here is a how-to on removing the guides:

http://forums.nicoclub.com/zerothread/105618