2006 Pathfinder: replacing timing chains, adjusting valves

Maintenance/Repairs
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1

So, I’ve got my Pathfinder (2006 / 160K miles) timing case opened, and this is what I see inside:

Basically, the passenger side chain ate through the tensioner shoe, driver side ate it not completely yet, but is on the last leg too. Obviously, both chains and tensioner shoes are to be replaced, passenger side tensioner is under question, I’ve still not seen if chain damaged the plunger.

I would not bring it up for the community attention (maybe after completing it), but I’ve hit a wall and need an advise, as Nissan Factory Service Manual contradicts to what I see in the front of me…

It instructs to get crankshaft to cylinder 1 TDC:

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Here I’ve immediately noticed that manual described marks do not result in valves to be up symmetrically, they are looking like they passed too far clockwise.

If I’m checking the proper chain placement page:

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Here what I see in my case:

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On both sides, all 4 sprocket are around 30 degrees to the right, clock-wise shifted.

The crank sprocket is also shifted clock-wise to compare to the shop manual:

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So, all looks to me like my harmonic balancer has wrong marks on it. Besides, the bolt is also supposed to have 60-degrees marks, but it has 90-degrees marks (?!?).

I’ve checked the cylinder 1 itself, and no way it is TDC, piston in not in top position.

So, I wanted to ask experts to verify my findings and to please give advise on an alternative TDC placement.

So far my idea was to get the best from the marks on the timing sprokets and make my own timing marks on the harmonic balancer, then go by the shop manual.

BTW, 19 out of 24 valves are in +0.02…0.06 mm over the maximum range, so I go for the valve lifters (fixed!) replacement in this job as well, but I need to get TDC issue resolved first.

2

It’s hard to see any timing marks at all in your photos. One thing I notice is there’s a clear mark on the bottom photo at about 10 am above the crankshaft sprocket, which seems like it should align with the little tab on the sprocket according to the diagram. So it appears to me that the crankshaft is rotated too far clockwise to be at TDC; i.e. the tab is pointed at 2 pm, not 10 am. Are you able to post a better photo of the timing marks that are supposed to appear at about 5 pm on the crank sprocket? Item 6 in the diagram.

3

One friend of mine just suggested he was fixing a 3.5L Maxima (similar engine design) and harmonic balancer had an outer ring to slip past the inner metal part: it has a rubber insert molded in and it rotated, but in his case it almost fell off. Mine looks OK so far, but looks like rubber has already detached form the metal

Looks like I would need to replace this part…

EDITED: looks to be not the case, I’ve checked few pictures of replacement good parts, crankshaft key and marks seem to be in the same positions I have:


4

I’ve never had to deal with that complicated of timing chain system myself. But when I set the valve timing on my 4 banger Corolla as part of a timing belt job, I didn’t rely on the crankshaft pulley (harmonic balancer) to set the timing, I relied on the marks on the crankshaft sprocket. I don’t recall there being any disagreement b/t the sprocket and the pulley, but I didn’t refer to the marks on the pulley when setting the timing belt. Only the marks on the sprocket. The angle you show the crank sprocket on your bottom photo blocks out any timing marks that might be present.

5

You’ve gone this far, so it seems like you should replace the harmonic balancer and then start from scratch. Set the crankshaft in the proper position with the new crankshaft pulley in place and then, with no chain at all, turn the right cam sprocket until it’s in the correct place.

6

Be careful when turning either the camshaft or crankshaft with the timing chain removed, b/c the valves could interfere with the pistons if this is an interference engine. You don’t want to make this a bigger job than it is.

7

I’[m gonna go by the sprockets. Looks like this is the safer approach.

8

Balancer seem to be not properly marked for TDC, no difference if this is the one I have or a new one.
Looks like Shop Maual has an error suggesting it is TDC.
At least, it seem to be that engine shafts are in balance: camshaft is not pushing on valves at this mark, so it looks like I’m not about to hit valves against the pistons.

9

That seems difficult to believe. Every engine I’ve set the ignition timing (which admittedly isn’t a lot, just a driveway diy’er) had a mark on the balancer for TDC, and a corresponding mark or pointer attached to the block. Sometimes the marking is a little confusing though. And the balancer can come apart, and cause piston TDC not to align with the mark. That’s not an uncommon thing in older cars. Seems unlikely in a 2006, but still possible. You can verify tdc by removing the spark plug from number one, and placing a wooden dowel into the hole until it hits the piston. If you want exact tdc you’d use a dial indicator to find the exact top of piston travel.

10

I’ve ended up watching piston movement with a stick and indeed balancer marks were not even close to TDC, although I’ve checked pictures of other balancers and mine seem to be not anyho different from the new one.

Anyway, marks on sprockets apparently had corresponding marks on the timing case, same as mark on the crankshaft key also had a notch on the case, so I’m all good now. Sure enough, Nissan dealer’s repair manual did not mention a thing about these marks, but YouTube was of great help.

Moreover, I’ve already removed timing chains and camshafts on one of sides, measured valve lifters there too. Having another side disassembled/measured tomorrow and getting ready to order parts.

Lifters seem to be a painful topic although: they are $20 a piece in the most discounted Nissan parts store, and I have 19 valves out of spec… I’m thinking about playing a “tetris game” with lifters I would have to remove - maybe I will be able to reuse some on other valves.

11

Does your Nissan use hydraulic lifters? If so once you get them back to spec be sure to follow the manufacture’s oil spec and oil and filter change out interval recommendations.

12

fixed lifters, will need to replace 19 of them, but before that I will have is to replace valve seals :slight_smile:

13

my dohc motor manual said to set crank to 60btdc if cam belt is removed. this puts pistons down in bores so cams can be rotated independently of crank. but it is not a nissan motor

14

on this V6 they seem to suggest a different approach: cylinder 1 gets to TDC, but valves are shut, the rest of valves are all around, but pistons are down

15

guys, I’m really hitting a wall I did not anticipate

I’ve just ran around the part stores to find a valve spring compressor tool, but it looks like nobody carries anything like what manual suggests to use:

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I did find some tools with similar number from Kent More, but the price is something around $500 (?!?!)

I’m not yet even talking about the tool to remove valve seals (step 5).

Likely need some advice from local professionals like @Tester or @db4690 !

16

The special valve spring compressor is required because the valve springs sit in wells.

So a conventional on-the-engine valve spring compressor won’t work.

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This is where you fabricate something in the shop that will do the same job.

Tester

17

I’m kinda scratching my head about fabricating something… but was hoping you will pull some trick like you did with a nylon rope :slight_smile:

18

How 'bout this?

Tester

19

You can buy a similar tool like this;

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This might work better;
Valve%20spring%20compressor2

I have replaced hundreds of valve springs with a magnetic valve keeper installer like this;
valve-keeper-remover-and-installer_300
Just push the tool down by hand to remove or install the spring and keepers.

20

This is essentially a generic version of the tool you showed us. Much less than $500. Less than $150, actually

But I can’t guarantee it will work for your application.

Click on this link. It’s schley tools, the manufacturer of that tool I just showed you.

https://www.sptool.com/product/91400b-updated-universal-ohc-valve-spring-compressor/