Cam intake sprocket is VVT. Removed incorrectly. Is it damaged?

[LeWidget]

So, I'm not sure if I have an issue or not.

 

When I started removing the cylinder head for the head gasket job, I followed a manual I had for the Pulsar N16 which said to set piston 1 to TDC then holding intake camshaft with spanner, use breaker bar to remove intake sprocket bolt. Did that, removed the sprocket, did the exhaust, removed cams etc.. to where I am now.

 

Today I got my hands on Haynes service manual for the Nissan Pulsar N16 and while reading, the removal of the intake cams is different. The Haynes manual actually mentions something about using compressed air to engage/disengage a locking pin, then using a allen key, lock the pin in place. But it also says not to remove the allen key before installing otherwise it'll damage the pin & a new sprocket would be needed.

 

Well... I'm stumped here. I don't know what to do, how to check if there's issues, where to proceed.

 

I had hoped to have everything done in the next day or two but this may have set me back even longer.

 

Does anyone know what Haynes is talking about? What should I do at this point? How can I tell if this is damaged or re-usable?

cam sprocket removalNissan pulsar n16.pdf

[LeWidget]

 

[UPDATE]

So, my curiosity got the better of me. It's my biggest flaw imo. I pulled the VVT apart to have a look inside & see if anything's broken. I am really confused...

I expected there to be some sort of wound-spring creating a lot of tension inside hence why the 'pin' would shear. There's barely anything in here & nothing's under tension. The pin was in 'lock' position which I could pull out and move the internals. My mind is still boggled how these things work, why it's necessary to remove the sprocket the Haynes way & why Haynes would say the 'pin' would be damaged and shear if the allen key is removed while the sprocket it out of the engine .

Am I missing something? I'm not a smart person so I'm assuming I am missing a lot about this situation.. 

 

[joshuaho96]

7 hours ago, LeWidget said:

 

[UPDATE]

So, my curiosity got the better of me. It's my biggest flaw imo. I pulled the VVT apart to have a look inside & see if anything's broken. I am really confused...

I expected there to be some sort of wound-spring creating a lot of tension inside hence why the 'pin' would shear. There's barely anything in here & nothing's under tension. The pin was in 'lock' position which I could pull out and move the internals. My mind is still boggled how these things work, why it's necessary to remove the sprocket the Haynes way & why Haynes would say the 'pin' would be damaged and shear if the allen key is removed while the sprocket it out of the engine .

Am I missing something? I'm not a smart person so I'm assuming I am missing a lot about this situation.. 

 

The Haynes manual is basically telling you to retract the locking pin in the VVT cam phaser and then advance the sprocket all the way to the limit of travel and use a pin to hold it there. Why it tells you that I'm not sure. Go by the factory service manual instead for your car/engine. It's possible you have to do the same procedure but I have literally never heard of anything like this when timing a VVT engine. You can verify that the pin is not ruined by checking that it is straight, no visible gouging on the surface finish, and no cracks or anything like that. The pin is designed to basically work such that when oil pressure is removed from the cam phaser it will naturally retard and hit the lock position at which point the spring pushes the pin into the hardened lock pin seat. Cam phasing is adjusted from there by using a solenoid that controls how much oil pressure goes to each side of the cam phaser. You can see a breakdown of how it works on a Toyota version of the same idea here:

 

[joshuaho96]

This is another good video that focuses much more specifically on the locking pin.

[LeWidget]

Thanks Josh, much appreciated

It's getting clearer what these VVT gears are & how they function. As long as the solenoid is good & the oil passages are clean, the VVT gear-sprocket should function as intended?
I'm still boggled about what Haynes is saying regarding the damage to the pin & the pin sheering. Still has me a little concerned even though I can't see how it would sheer.
I might take everything apart tonight, give it a good clean, inspect & re-oil.

Regarding the factory service manual. The one I have seems to be a factory service manual for Europe, however, it says it was released in 2001, though my car is a late 03' built in Japan (imported to Australia), so I'm not sure if there's a newer / later release of the manual, or if it covers 'series 2' QG18DE, or if Europe models varies differently to Japan/Australia models. I've been looking for a different factory manual but no luck so far.

[EDIT] I took a photo of the compliance plate in the engine bay which has a model number stamped into it. Is anyone able to decode. Perhaps it would give more information on the engine or if anything's different with this variant ? CATARDAN16EMA-F---

 

Edited August 5, 2023 by LeWidget

[joshuaho96]

On 8/4/2023 at 11:23 PM, LeWidget said:

Thanks Josh, much appreciated

It's getting clearer what these VVT gears are & how they function. As long as the solenoid is good & the oil passages are clean, the VVT gear-sprocket should function as intended?
I'm still boggled about what Haynes is saying regarding the damage to the pin & the pin sheering. Still has me a little concerned even though I can't see how it would sheer.
I might take everything apart tonight, give it a good clean, inspect & re-oil.

Regarding the factory service manual. The one I have seems to be a factory service manual for Europe, however, it says it was released in 2001, though my car is a late 03' built in Japan (imported to Australia), so I'm not sure if there's a newer / later release of the manual, or if it covers 'series 2' QG18DE, or if Europe models varies differently to Japan/Australia models. I've been looking for a different factory manual but no luck so far.

[EDIT] I took a photo of the compliance plate in the engine bay which has a model number stamped into it. Is anyone able to decode. Perhaps it would give more information on the engine or if anything's different with this variant ? CATARDAN16EMA-F---

 

When I check nicoclub for the 2005 Sentra factory service manual it mentions this step, so I would follow it.

[LeWidget]

Thanks Josh :). As the VVT /VCT is already off, I'll be sure to follow when re-installing. 👍

You would happen to know the torque requirements for the 3 bolts securing the VVT/VCT housing? I've looked in my Haynes manual & a Nissan Almera (Pulsar in Europe) factory service manual, but can't see anything, unless I'm searching the incorrect name. If the VVT has 3 bolts allowing it to be disassembled as shown, there 'must' be a torque specification to tighten them back up, no? 

Thanks again

Edited August 9, 2023 by LeWidget

[joshuaho96]

14 hours ago, LeWidget said:

Thanks Josh :). As the VVT /VCT is already off, I'll be sure to follow when re-installing. 👍

You would happen to know the torque requirements for the 3 bolts securing the VVT/VCT housing? I've looked in my Haynes manual & a Nissan Almera (Pulsar in Europe) factory service manual, but can't see anything, unless I'm searching the incorrect name. If the VVT has 3 bolts allowing it to be disassembled as shown, there 'must' be a torque specification to tighten them back up, no? 

Thanks again

https://www.nicoclub.com/service-manual?fsm=Sentra%2F2005%2Fem.pdf

As far as I can tell there is no listed torque spec as it was not intended to be disassembled. It is probably either something like 7 ft-lbs or 12 ft-lbs. Assess what materials you're tightening into. If it's soft aluminum 5-7 ft-lbs is probably what you want.

[LeWidget]

12 hours ago, joshuaho96 said:

https://www.nicoclub.com/service-manual?fsm=Sentra%2F2005%2Fem.pdf

As far as I can tell there is no listed torque spec as it was not intended to be disassembled. It is probably either something like 7 ft-lbs or 12 ft-lbs. Assess what materials you're tightening into. If it's soft aluminum 5-7 ft-lbs is probably what you want.

Thanks again Josh, much appreciate the information  .

I used a magnet on the sprocket and it looks like the section that the bolts thread into is machined from steel (magnetic). As I hadn't found anything on it, I was considering just tightening them to 10-12nm (7.3 - 8.8 ft-lb), but maybe I should aim for a higher torque being it's inside the engine?

Do you think the use of threadlocker (blue) would benefit ?

[joshuaho96]

2 hours ago, LeWidget said:

Thanks again Josh, much appreciate the information  .

I used a magnet on the sprocket and it looks like the section that the bolts thread into is machined from steel (magnetic). As I hadn't found anything on it, I was considering just tightening them to 10-12nm (7.3 - 8.8 ft-lb), but maybe I should aim for a higher torque being it's inside the engine?

Do you think the use of threadlocker (blue) would benefit ?

Blue threadlocker + tightening by feel is probably the way to go then. You can feel fastener stretch. At first it will be relatively easy but usually you will hit a sudden increase in resistance. Once you get there don't go crazy with the force. A bit more is good enough.