[andrew.ashton]

Hi forum members,

A cry for help (and a bit of commiseration wouldn't go amiss too).

My 2002 Gen3 LWB Auto paj and I have been in relationship since 2005 (since about 70k km).

I swear I have never mistreated her and have always been faithful.
I tow a Halcat from Jhb to Bronkhorstspruit once a year maybe.
In all the years I have had her I have never seen the water temp needle go above horizontal.
I rarely exceed 2600 rpm, preferring to travel at 2000 rpm highway driving.
She purrs along, does not use coolant, does not use oil between service oil changes, and gets better consumption than many despite ARB + long range tank + roof rack.

Knowing that grande dames of her experience - 225 k km (lets not talk about age) may experience some dental problems I promised to replace her upper timing chain guide.

So today I took off all the paraphenalia to get to this - my goodness - with my Beetle it just used to be a spring clip and you had the rocker covers off - nothing that simple for the cunning Japanese. (It leaves me wondering what you short guys do when you have a raised paj with an ARB bar?)

Sure enough the original upper guide was in the process of failing - a crack near the leading edge of the bearing surface of the guide.

Crack on chain guide at right hand end

Easy enough to fix with a new guide.

But wait - what's that? Cracks across the head on the section on which the second camshaft holder sits.

Crack below 2nd camshaft holder on inlet side

Crack below 2nd camshaft holder on exhaust side

Oh cr*p.
Q1. What do I do now? (Given that I must continue the relationship)
Q2. What can let go?
Q3. What can be the consequences of that letting go?

If I had not taken the rocker cover off I would have been none the wiser.

[4ePajero]

Are you sure those are cracks?
Clean the oil away and take more pics.

Sent by 4e, from my iPad using Forum Runner

[andrew.ashton]

Hi Gerhard,

Appreciate your prompt feedback.

I will strip again and take some more photos - but they look v much like cracks to me.

It would seem strange to have casting defects on both sides of #2 cap bases? And none of the other cap bases display that effect.

But like I said, no symptoms - so maybe (please, please) I am panicking unnecessarily?

[4ePikanini]

yours looks a bit rougher than mine but mine also has a "crack" looking joint there. I think it's just part of the manufacturing process.

If that was a crack it would fail very quickly due to aluminium's properties and the loads that will be exerted by the valve springs through the rockers onto the camshaft.

Here is a pic I dug up from a few thousand kms ago of my second cam caps.

[andrew.ashton]

Thanks Marius,

Really appreciate the feedback.
I didn't realise / expect the casting to be that rough / irregular - its the first time I have taken the rocker cover off. Somehow expected something better from Japan!

I know I have read somewhere that there is a design failure point (to prevent bottom end destruction if a piston collects a valve) but as far as I recall it is the cap that is supposed to fracture, not the head.

As I said to Gerhard, I want to be double sure so I will strip again and take some photos with my camera instead of my phone after blotting away the oil.

[paw_by_paw]

Andrew,
That looks like a casting mark to me.
The mould might be old already or just have not been bolted correctly before pouring the alloy. It makes me wonder about quality control fro Mitsu Normally these marks would be detected and skimmed off to make the job look nicer but it seems it skipped that process. I might be wrong though. Have you tried to insert a very thin feeler gauge maybe to see if it enters

[KaiV]

I also think that these are casting marks. In 4e's case, just a bit "nicer" looking.
If you really wanna put your mind at ease, buy some di pen and do a test.
Buy all three (cleaner, di penetrant and developer) Clean as best you can, spray cleaner, let it dry, spray penetrant, let dry and wipe excess away, then the developer. If it is a crack, the red penetrant will make its appearance known, trust me.

M2CW is that shes still good to go

[CATS]

Pretty sure that aint a crack. IIRC mine looks about the same. Maybe they came of the same dye?

CATS

[CATS]

By the way. This is what my top chain guide looked like when it was removed some many moons ago!



CATS

[andrew.ashton]

Hi Guys,

I REALLY appreciate all your feedback.

I also think that these are casting marks. In 4e's case, just a bit "nicer" looking.
If you really wanna put your mind at ease, buy some di pen and do a test.

I think that KaiV's suggestion of a dye penetration test is a good idea - as you say - to put my mind at ease. Will have to be a next week job. Any idea where I might source such a set?

Even if the original post makes me look a bit dom I am going to leave it up - others can learn from it.

By the way. This is what my top chain guide looked like when it was removed some many moons ago!
CATS

Yup - very happy that I tackled this before mine got to that state.

Andrew,
That looks like a casting mark to me.
The mould might be old already or just have not been bolted correctly before pouring the alloy. It makes me wonder about quality control from Mitsu

When you hear of paj heads failing then you wonder if something like this is not behind some of those (although most are probably brought on by other root causes).