Hi All, I'm pulling the head on a 2003 2.5 engine. It's all going well, but the intake sprocket bolt is just not busting loose. It makes me wonder if it is a left-hand thread (loosens clockwise)? We've heated it a couple times, but no luck. The exhaust sprocket bolt came out no problem. Any advise?

Thanks,

Filippo

Hey, welcome to NICO Club!

It doesn't seem to be reverse threaded, besides, it spins the same direction as the other cam. Be sure to use the FSM for your work and mark all your stuff as you go.

This will help if you don't have it already:
http://www.nicoclub.com/service-manual? ... 0Altima/EM

Thanks for the manual reference. Unfortunately it is lacking to reality:
Secure the hexagonal part of camshaft with a suitable tool.
Loosen the camshaft sprocket mounting bolts and remove the camshaft sprockets."

This is akin to, "hear a miracle occurs". The exhaust sprocket bolt comes off no problem, with a bit of heat. The intake sprocket bolt is a whole nother matter. I've heated it up to about 250 degrees several times. I secured the camshaft with a 15/16" wrench (fits tighter than the metric wrench). I first tried with a 17mm impact socket on a 2' long breaker bar. No luck. I then busted out the Milwaukee 1/2" High Impact torque wrench. I could get it on there with a flex impact extension and 17mm impact. Heated again to 250 degrees. No dice. Heated the camshaft as well. No dice. Oil continues to exit from the bolt side (must be in the variable cam timing sprocket housing?) ... but nonetheless 4 or 5 attempts with heat and I cannot get the intake sprocket bolt to loosen up.

Any wisdom to share? Thanks.

Filippo

Just to close the loop for any other poor bastard that might come along and find this thread. I heated the bolt at least 4 times to 250 degrees or so. Two times I heated the camshaft as well. 1/2" breaker bar didn't do it. Milwaukee High Impact 1/2" M18 torque gun didn't do it, though I had to use a flex extension on the 17mm bolt which likely killed the impact enough to not work. Finally I took a 1/2" extension breaker bar, put a pipe on it, and it took my pushing on it about 3-4 feet out to break the thing loose. It is a b****. Also one other trick. A 15/16" Snap-On combination wrench worked better on the camshaft than the correct metric wrench. I put a block of wood between the wrench and intake, which kept it from moving. Guys ... I read about it on the Internet, and I'm here to say they were right - the bolt is a b****. 4' breaker bar is what you'll need.

Filippo

Dang! So it's practically welded on? Well, I'm glad you got it off and didn't bend or strip anything. Thanks for the feedback also. It does screw off, you just gotta use a lot of force.

Why are you taking all of this apart anyway?

Like I read on several forum posts, the intake cam sprocket bolt is on there super hard. Screws off counter-clockwise.

We bought the car with 130k miles. Ran great but I now know the previous owner did a head gasket, and obviously did not send the head to the machine shop to be milled flat. The new gasket worked for a while but eventually blew (given the less than flat head). I'm now rectifying that issue.

Filippo