Diagnosing Slipped Cam Chain VE LEO 2006

[OZTRAX]

Looks good, you also dont have a lot of wear on your camlobes, so you may have gotten it in time, I was at your exact point then assembled the engine back together with new chains tensioners oil pump water pump etc and when we started her it was a no go as the chain must have slipped on the cog at intitail breakdown enough to cause my whole left bank to have bent valves.

Simsol, i had a read of your thread on slipped chain/bent valves.

My engine is a LEO and yours a LY7, LEO being lower power may have less interference valves/piston.
Secondly my right bank cam timing chain slipped at startup/idle, yours at higher revs.
After replacing my chains, i believe the cam chain slips at the idler gear. This would retard both intake and exhaust valves. Also why i had the strange delayed pop when doing compression checks.

I assume my cam chain slipped maybe 3 teeth or so, Simsol yours may of been much more as you were at higher revs.

In retrospect, if from now on any members here suspect slipped timing chains, a compression check would be a great next step.
Maybe do a compression check with chains on, then chains off to confirm if valves are bent.

 

[OZTRAX]

My thoughts on de-sludge and timing chain replacement.

THE DE-SLUDGE PROCESS

So, to go from this:

TO THIS:

It's going to take the better part of 1 week...........

Sludge removal is 70% of the work. oil pan and camshafts and cam followers' removal also required.
The oil filter housing will have to be removed as well.

We scraped sludge and used a cleaning gun with kerosene (all 60 liters of it) to start removing this stuff, which is very hard to get off your hands and clothes. my wife-soaked clothes 3 times to clean my clothes. Its evil stuff.

For the sludge baked onto the cases you need this:

Yes, it seems a bit rough, but it's pretty well the only way to remove sludge that's against the metal cases, oil pan, heads, valve springs etc.
Hand parts cleaning brushes won't remove it.
I have a collection of different size steel WIRE WHEELS and red nylon brushes for my drills as I do TIG welding alum and stainless.
Only use the red nylons ones on gasket surfaces.

After wire brushing, hit it with the Kero cleaning gun, may need to repeat process up to 4 times to get all of it off.
Camshafts, sprockets, idlers, bolts and cam followers can go in parts cleaner and soak overnight, but its best to scrape as much off as you can and maybe hit it with the Kero cleaning gun as well.

Cleaning heads in situ is hard but can be done with a collection of different size wire brushes, just bunnings quality, nothing exotic or expensive.

Under car cleaning crankshaft bearing caps isn't fun, but also required wire wheels and Kero gun.
Oil pan requires disassembling and cleaning the 2 plates and pickup inside.

Oil passages clean out with Kero gun and high-pressure air.
When block has dried off use high pressure air, my air compressor is a new oil less twin cylinder and was up to the job. (and quiet)
You will find even after all your cleaning efforts that bits of dried sludge will still be coming off. The air was enough for me but if your keen you may want to keep cleaning, particularly the crankshaft bearing caps and oil passages with Kero gun and then air again, so on and so on.
Thinking about it later, may have been a good idea to remove crankshaft bearing caps one at a time and clean them.
But I promise you will be sick of cleaning this crap by the 4th day.

I didn't remove oil pump, but if it was my car i would and replace with higher output unit from Rev High $120?

Allow 4 days to do all the cleaning.

 

[OZTRAX]

DISASSEMBLY:

A few things I have learned if you're doing this for the first time.

Harmonic balancer can be done with a 3-jaw puller, yes, the holden one is better at $200 plus.
With the 3 jaw it can fit into the spokes of the inner part of balancer, even if you have to grind a bit off the legs.
Leave the balancer bolt loose about a 1 cm or so, and the end of the puller shaft pushing on this not the crankshaft end itself.
Supercheap $58

After balancer off, oil pan can be removed, don't need to move K frame or steering shaft, will need 13mm ring spanners and maybe someone underneath and above. Negative will be you won't get a socket or torque wrench on Apon assembly.

The air-conditioning compressor and bracket are hard to remove, you need to have a look on you tube or wherever to see where the bolts attach. Again, someone underneath and above helps.

There is a link on this forum to an electronic copy of holden service manual. I think it's for a VZ but read through this and you will get clear pictures of what you have to do. Also, good when installing cam chains, guides etc.

Then timing cover off, most of the bolts are the same size but there are a couple that are shorter, take note.

Oil filter housing can be removed after aircon compressor bracket, the gasket is not included in the Rev High kit.

It was my first time, so took me 1.5 days to complete disassembly, including camshafts and followers.

I took the plastic guide off the oil pump, but the Rev High kit has the guide and bracket. (*only way to get the guide from Holden is to buy a complete oil pump)
I personally would replace the oil pump as well with a Rev High higher output unit.

Camshafts easy to remove, try not to mix them up. If you do the back end of camshafts have a number on them which will have "LI, LE,RI, RE) at the end, e.g. RI right inlet etc., the camshaft bearing caps are marked as well with arrow and number.
Cam followers I just threw them in the parts cleaner overnight, after cleaning check for wear and then I dropped them in a small bottle of engine oil.
Same with phasers and sprockets. This is where the Holden service manual is really good to have.

Cleaning around the valve springs is hard and may take a stiff brush and some parts cleaner. In addition to air nozzle and cleaning gun.
Clean all oil passages with Kero gun and air nozzle.

 

[OZTRAX]

ASSEMBLY:

For parts you only need to remember 2 words "Rev" and "High.....................
Their $520 kit has chains, tensioners, all seals, guides etc.

But you will need extra:
the camshaft lock plates: $25 from Rev High
oil filter housing gasket
oil sump pickup seal

The left one is from AUTO 1 and is no good, the correct one on the right form Rev High, you can see the difference. OEM is nearly $50, Rev high $20.

I took about 4 hours to install all the chains etc. and used both the Rev High guide printed in color and the Holden service manual.
Triple checked everything, used the Stage 1 and Stage 2 system.

Photos attached.

The double check is to turn engine over via the harmonic balancer bolt 2 turns DOR, and then turn back 2 turns. Everything should still line up perfectly.
Take photos like I did so you don't wake up next day wondering if you did it correctly.........

I ended up installing oil pan after timing cover because i was still waiting on the oil pickup seal to arrive.
Oil pan first would have been easier.

With timing cover and sump on (rocker covers off) the engine can be cranked from starter motor to prime.
I reckon 3 lots of 20 seconds and you will see the timing chains starting to pick up oil and fling it off.

Well, that's about it, take it for a test drive and enjoy

regards
OZ

 

[OZTRAX]

UPDATE:

Hard work seems to have paid off. 1600 kms later and oil is clean, filter had tiniest bits of soft sludge. I think the cleaning with kerosene is the secret as this definitely dissolves sludge quite well.
Manual desludge of these engines with rocker,timing covers off and sump off is the go, it just involves a lot of elbow grease/ hard work to give a good result. To pay a mechanic to do this would be cost prohibitive.

OZ