First time - Valve Clearance & Upper Timing Chain

[scoott]

Hi all,
I am just looking at checking the valve clearances and to change the upper timing chain on my Diesel 2006 NP Pajero, and was hoping to ask a few rookie questions to gather some further information and be prepared for getting into the job. So I hope you don’t mind the bombardment of questions, I am just looking to gather as much info as I can prior to the job so it goes as smoothly as possible.

I have a copy of the Hayne’s manual as well as some digital content to go along with it. So if there are any other good sources of information please feel free to let me know!

My main questions were, how often do people check their valve clearances. I have heard the manufactures guide is 45,000km while a mechanic I have used who has worked on these engines multiple times as well as the Haynes manual recommend every 10,000km. I’m happy to do preventative maintenance but would be great to get an idea on how often you all have been checking yours.

Secondly, when re-installing the rocker cover. Is there an actual gasket or is there just a bit of gasket sealant you use to re-seal the cover, and is it recommended to change the seals on the valve cover mounting bolts each time? As I have been quoted around the $130 for a kit from Burson’s which include both gasket and bolt seals however not sure if this is overkill replacing every time, especially if checking every 10,000km.

With regards to the upper timing chain guide. I have read varying things on having to reset the tension on the chain when replacing. From what I can see in the photos, it simply looks to unscrew, and be replaced. Is this the case, or is there a reason when replacing this you must re-tension the chain?

Finally, while I have a good selection of tools. Are there any special or unique tools for these jobs that would make life easy or be wise to have in the kit?

Info on car:
81,000km on the clock
3.2L Diesel NP – 4M41 Engine
Unsure when last valve clearance would have been done. Most likely inline with manufactures recommendations as previous owner was very meticulous.

Cheers in advance!

[Morville]

The Gen 3 (NM, NP) owners manual says every 15k. However my experience with Gen 3 and Gen 4 is the clearance changes very little over time and every 60k is sufficient. I would do it now though to ensure the clearances are correct. There is detailed info about doing the job in Gen 3 and in Gen 4.1 by Goodsy I think. The Gen 4 valve adjustment procedure is similar to Gen 3 except on Gen 4 the injector lines need to be removed. Do not turn the engine backwards when doing the job as the timing chain tensioner will be damaged.
Peter

[El_Freddo]

I found when I did my timing chain guide that I had to remove the tensioner and reset it. It’s super easy and I was quite impressed about how simple thenwhole setup is.

Be sure not to over tension the cable guide retainer bolts. I think I may have stripped one of mine but left it as is to check on later.

My guide was the original unit and was cut half way though and bent up at about a 45 degree angle. Dodged a bullet there!



And an original 85,000km?! That’s a good find!! We love our NP, and continue to be pleased with our move to this model from a 2wd vehicle.

Cheers

Bennie

[scoott]

Thanks for the info guys, much appreciated. I'll have a look for those forum threads with the details to go along with the manual I have and hopefully give me some nice pictures which it lacks.



It certainly is Bennie, it actually just had over 70,000 when I bought it not too long ago and when I saw the ad I was a little doubtful. But it just hadn't seen a lot of use and was spotless. Love the motor in these things! Although fingers crossed my guide isn't like yours!



Cheers again guys

[Morville]

Hi Scoot, there is a sticky in the mechanical section called "I did my valve clearances today" by Goodsy. It is for a Gen 4.1 NS which requires the removal of the injector lines which yours doesn't. However the valve adjustment procedure is identical.
I did a writeup on doing valve clearances on my Gen 3 NM in about 2005, which appears no longer on the forum as it doesn't go that far back, unless someone can point out where to find it.
By the way that NM is still going strong today with about 400,000 on the clock. Apart from wheel bearings, a water pump and new radiator the only major issue was the Dual Mass flywheel failing at about 180,000. It still runs perfecly using very little oil and still has the original injector pump.
the current owner says they will scrap it if the pump fail rather than spend about $5k.
Peter