Bad pulley or what?

[paroxysym]

So I've noticed a banging/rattling at idle so I crawled under my jeep and have kind of pinpointed it to the front bottom end of the motor. I want to say its the crankshaft pulley, however I am wondering what else it could be? It's a 4.7 with 115k on her. Thoughts??

[Matt]

is it a consistent sound that's always there at idle, or is it intermittent?

happens when the engines warm or cold, or doesn't matter?

[paroxysym]

is it a consistent sound that's always there at idle, or is it intermittent?

happens when the engines warm or cold, or doesn't matter?

Doesn't happen at start up, takes a minute but once the rattle gets going its pretty constant at idle.

[Matt]

Take the serp belt off. Manually spin all of the pulleys to see if there's a dead giveaway. If you're unsure, start the engine with the belt off and see if the noise is there (won't hurt anything to run it like this at idle for a few minutes... just watch the temp gauge)

[paroxysym]

i noticed it does it more when there is not load per say on the engine- when im sitting in neutral, foot on the brake just idling its more constent. when its in drive and i have my foot on the brake it does it but its more intermittent.

[paroxysym]

well.... found the source of the sound- bad crankshaft pulley. after stopping for gas yesterday and popping the hood while it was running, you can see the crankshaft pulley has some play it in at idle, theres a bit of a wobble to it.

so im thinking ill be ordering a new one from rockauto, local shop wants $200 to install it

[07JeepXK]

well.... found the source of the sound- bad crankshaft pulley. after stopping for gas yesterday and popping the hood while it was running, you can see the crankshaft pulley has some play it in at idle, theres a bit of a wobble to it.

so im thinking ill be ordering a new one from rockauto, local shop wants $200 to install it

$200 to install a crank pulley?!?!? You can do that yourself. I'd recommend changing out the front seal while the pulley is off.

[paroxysym]

$200 to install a crank pulley?!?!? You can do that yourself. I'd recommend changing out the front seal while the pulley is off.

yea $200 to drain and fill the radiator since that has to come out and the fan and stuff, as well as install the new balancer. i didnt see a seal on rockauto..

i just priced one on rock auto and a new belt- those along with new front brake pads and new wheel speed sensors was $180 shipped, i love that site.

i cant believe coolant is so much- she is due for a flush

[06JeepXKHEMI]

I think he's referring to the crank seal..

[07JeepXK]

yea $200 to drain and fill the radiator since that has to come out and the fan and stuff, as well as install the new balancer. i didnt see a seal on rockauto..

i just priced one on rock auto and a new belt- those along with new front brake pads and new wheel speed sensors was $180 shipped, i love that site.

i cant believe coolant is so much- she is due for a flush

Ummm who told you the radiator has to come out to replace the crank pulley?!?!? I hope it wasn't your mechanic or I'd highly recommend finding a new one ASAP. As far as the seal I got mine right from the dealer to ensure I was getting the correct seal.

[paroxysym]

I think he's referring to the crank seal..

found it, $7 lol

[07JeepXK]

Did you read my last post? I too have a 4.7 liter and have had that pulley off to replace the front main seal. The radiator doesn't need to come out.

[paroxysym]

Did you read my last post? I too have a 4.7 liter and have had that pulley off to replace the front main seal. The radiator doesn't need to come out.

ah missed that post- im thinking i had it mized up. i called to get a price on the install and i know they have to remove the fan and stuff, mayeb i threw in radiator. im swinging by there this week to have them take a look.

how much was the dealer part?

[07JeepXK]

I can't remember the price but I know it wasn't all that expensive for the seal.

[paroxysym]

timken or national is the brand that rockauto carries, as for the harmonic balancer the brand i found on rockauto is dorman.

[07JeepXK]

I prefer Timken but that's just me.

[paroxysym]

Found the source and fixed it in 3mins. Apparently the bolt closest to the firewall that holds the heat shield in place for the exhaust manifold has snapped off. So the heat shield was rattling against the manifold. I took a pry bar and pried it back enough so it wasn't making any contact- noise and rattling gone. So glad I just saved myself $250.

Now what's my move with this? Let it go? Idk how I'd repair this... Unless I replaced the manifolds and fixed it then.

[07JeepXK]

Pull that manifold, weld a nut to what's left of the broken manifold stud and back it out. I had the same issue. It's very common for that bolt to snap on the 4.7