4.0 V6 Cologne timing chain explosion!

[RatCav]

I removed the RH (rear) tensioner and it only partially compresses 1/4" at most. It then goes solid. It isn't any harder or easier to depress than the new one up to that point. Reading your advice I am going with the new tensioners. You mentioned that if the tensioner doesn't compress it can cause further damage. Not going to risk it .. especially as you need to remove the engine to replace the rear chain guides.

Strangely the RH chain and guide set are about the only thing intact. Everything else has been destroyed (except the main chain static guide and balance shaft static chain guide).

I spent ages rotating the crank to TDC (2 complete revolutions each time). At no point did the marks on the balance shaft sprocket line up with the 4 mm hole. I have a big suspicion that the engine has been out before due to missing bolts and such like. I also seem to recollect the previous owner saying that the chains had been done (was a selling point) but was unsure if the rear one was done. It is entirely possible that the balance shaft chain was changed, and the person doing it failed to time it properly before fitting the new one. I am going to have to sort that one out when assembling it.

 

[RatCav]

After a bit of time double checking everything and making sure I have got it right so far I made up a tool to lock the front jackshaft sprocket. Found a bit of 4mm flat and drilled three holes in it and cut out a notch. I bolted it to one of the bolt holes for the A/C compressor/Power Steering Pump mount bracket, using another nut as a spacer. I then cut down an M10 rod I had lying around to two small lengths around 70mm long. Fixed those into the other holes. Once mounted the notch allows access to the torx bolt that is in the end of the shaft.

So that is the Crankshaft locked, the Camshafts locked, and the front Jackshaft sprocket locked.

All that is left to do is modify a tensioner to use as a setting tensioner.

 

[C420sailor]

Those plastic cassettes suck. I'm in the middle of swapping my tired (and noisy) '98 SOHC engine out for a '11 Ranger engine. I popped the valve covers off and discovered that the outboard front chain cassette was completely gone---it had broken off and was sitting, largely intact, in the bottom of the engine. The tensioner was fully extended, and doing a half decent job of keeping the chain taut. Engine had 205k on it, and I'm very surprised it didn't jump any teeth and start sh!tting out valves...

 

[RatCav]

The land Rover boys and girls complaining about the petrol V6 in the Discovery 3 is a very common thing over here. Also coupled with the cost of repairing it and the high servicing costs. It was only recently I found out that it is the same engine and now I understand why it is such a pain. Land Rover parts aren't the cheapest for this sort of thing. In fact it is cheaper, and as quick (in some cases) to buy a good OEM spec parts from the States and have them shipped than it is to buy pattern parts over here.

 

[dezufo]

What is the progress on this?
Was hoping to see the dimensions of your custom tooling

 

[RatCav]

Firstly apologies for the delay. Family crisis intervened.

Glad to report the engine is in and running well (on petrol). Had a couple of incidents. Leaking thermostat housing, and I bust the oil pressure sensor on engine install. Slight air leak between the inlet manifolds and a fuel line o'ring split. All that is now fixed. Only thing left to do is re-fill the air-con gas and tune the LPG system. It ran well on LPG before, but now it just doesn't idle at all and will stall on LPG all the time. I must of put it back ever so slightly out (or it was out before hand) to make the difference. On petrol however she is performing wonderfully. Pulls like a train and sounds really smooth.

Some pictures:

Old Cam chain left, new Cam chain right. Difference of about 4mm on the length. This was the same both front and back.

Old rear tensioner left. New rear tensioner right:

New front chains and guides. I had to remove the balance shaft to get it timed up properly and fit the chain on. However all the bits are present and correct now (as opposed to floating in the sump and the balance shaft was out of time)

Front timing chain install:

Rear timing chain install:

Thing to note on the chain set install. The front guide is a pain to get in with the recommended method of assembling and holding together with an elastic band. Getting it past the top of the head of the main block is tight. I eventually took the elastic band off. I lowered the guide down into the hole and opened it to get past the castings. I then lowered the chain down and dropped the lower pulley into the loop of the chain. placed the top pulley into the loop at the top and then wriggled everything into place and bolted down.

Fitting the engine back into the car is easier by putting the torque converter onto the gearbox input shaft first. Then mate the engine onto the gearbox. Then you can turn the torque converter until the studs line up with the holes on the flywheel (all accessed through the starter motor hole) and put the nuts on.

All in all relatively painless. I will recover my locking set later and draw it all up and make a fileset for download for peoples benefit.

 

[dezufo]

No need for apologies family is more important.
Good to see that you have got it up and running.
Looking forward to your fileset.
With regard to the LPG side;
Is it a multi-point?
Does it stall when pulling away from a stop and just after it has switched over to lpg?
Does it stall once the temp gauge has reached the minimum mark, thats the first line up from the C mark?
Did you disable the lpg for the first road test?

 

[RatCav]

We ran it on petrol for a while to shake everything out. Then I connected the multipoint injector LPG system back in. It will switch over to LPG but runs lumpy and will not idle. Just wind down and stall. If you have any throttle it won't stall at all. It is definitely a mixture issue as opposed to a mechanical one. Just needs plugging in and tuning.