One of the write ups I have read on how to do it didn't mention the drain plug and just removed the lower hose form the water pump. I will try the drain plug but it is good to know if it doesn't come out it is not the end of the world.

I am not going to remove the exhaust manifold I am just going to unbolt it and move it out of the way, I know this is possible because I have replaced the manifold gasket recently without removing it.

Do I need to remove the glow plugs and injectors? It looks like some do and some don't. I will need to buy the required tools first if I need to remove the injectors.

Finally, is it worth rebuilding (after checking the cam sprocket, and assuming it is fine) the timing belt/cover/front end, before removing the head. This way I have less to risk going missing and there is no connection between the two jobs?

You don't need to pull out either glow plugs or injectors to remove the head. You only need to the fuel delivery lines to the injectors, remove the manifolds, the rocker assembly and drain the coolant via the drain plug on the side of the block so as to ensure that no coolant seeps into parts that it shouldn't when the head comes off.
The way I see it, valves are opening out of phase, and if you've confirmed that none are bent as you say you have, I would really be taking a closer look at the cam drive/timing.
What exactly are you on the lookout for with the head removed?
 
One of the write ups I have read on how to do it didn't mention the drain plug and just removed the lower hose form the water pump. I will try the drain plug but it is good to know if it doesn't come out it is not the end of the world.

I am not going to remove the exhaust manifold I am just going to unbolt it and move it out of the way, I know this is possible because I have replaced the manifold gasket recently without removing it.

Do I need to remove the glow plugs and injectors? It looks like some do and some don't. I will need to buy the required tools first if I need to remove the injectors.

Finally, is it worth rebuilding (after checking the cam sprocket, and assuming it is fine) the timing belt/cover/front end, before removing the head. This way I have less to risk going missing and there is no connection between the two jobs?
From (a poor) memory the injectors protrude slightly but if you lie the head on the manifold edge it'll be ok. I would take them out though if you end up working on the head, you don't want dirt getting in them.
Build the front end up first if you want to, it won't affect the head work.
 
The way I see it, valves are opening out of phase, and if you've confirmed that none are bent as you say you have, I would really be taking a closer look at the cam drive/timing.
What exactly are you on the lookout for with the head removed?

As was suggested earlier in the thread to test the valves are sealing correctly I removed the rocker shaft and span the engine over on the starter. With no rocker shaft fitted all valves should have been closed and sealed. However I go the same "chuffing" out of the intake manifold as was previously shown in the video I uploaded. This indicated that the valves are not sealing correctly regardless of the timing issues there may also be.

I am going to check the cam sprocket this evening and providing there is no damage and I do not need to wait for replacement parts will then rebuild the front end after timing everything up.
 
I would take them out though if you end up working on the head, you don't want dirt getting in them.
I am assuming they are no more difficult to take out on of the head on the bench than fitted if I remove it for inspection and then find it needs work? If I need to remove them for other work I may get them refurbed a the same time as this is on my list anyway and they have done nearly 300k.
 
It's easier to remove them with the head on. I've never had an issue getting them out thus far anyways.
You can twist them with a spanner to help loosen them, clockwise only or they will come apart.
 
Cam shaft sprocket and keyway shown in the pics below:

IMG_0775.JPG IMG_0776.JPG

I spent last night in the cold, wet, and dark refitting the timing belt, and the rest of the front end. However as I type this I cannot remember if I torqued up the camshaft retaining bolt, I definitely tightened it down with the ratchet but cannot recall if i then checked it with the torque wrench. I am sure I will have done but will probably strip it back down to double check! Once I have doe this I will remove the head and see what horrors await me.

I am supposed to be out for dinner with friends this evening so not sure how far I will get but will hopefully at least get the timing belt boxed off and completed.
 
Quick video of the same test as before (no rocker shaft) but with the intake removed in an attempt to see which cylinders are causing the problem:

(apologies for the poor quality it was dark and wet)

 
Managed to remove the head fairly easily, below are the pictures of what I found. To me there was nothing immediately obvious the was damaged but this is the first time I have head the head off so am probably missing something. The only thing I noticed was there is a fair amount of carbon build up around the valves.

IMG_0783.JPG

Cylinder 1
IMG_0787.JPG

Cylinder 2
IMG_0786.JPG

Cylinder 3
IMG_0785.JPG

Cylinder 4
IMG_0784.JPG

And then the cylinders themselves:

Cylinder 1
IMG_0789.JPG

Cylinder 2
IMG_0790.JPG

Cylinder 3
IMG_0791.JPG

Cylinder 4
IMG_0792.JPG
 
Now I have got to this stage what would by my next course of action. I was kind of hoping to see an obviously mangled valve making it a simple case of replacing it. Would it just be to clean everything and re-lap/re-seat the the valves? Or is there something I am missing?

I am also going to put in a parts order as I need a gasket and bolt kit, from the photos above what other parts will I need to resolve the problem/what else is it worth replacing as I have already got this far? If I can get them ordered today hopefully they will be here ready for the weekend.
 
Number 1 piston looks like it's got a valve contact mark in it?
I'd pop them all out and check them, decoke and grind them in.
Check the valve guides for wear too as well as the valve stems.
It's a pity a compression test wasn't carried out before the strip down.
 
Number 1 piston looks like it's got a valve contact mark in it?

Yes Piston 1 looks to have a contact mark and that is the one which can be seem exhausting out of the intake in the video.

I'd pop them all out and check them, decoke and grind them in.

I am assuming that in order to do this I need to first carefully remove and inspect them as suggested by @jamesmartin before decoking and lapping back in. Any suggestion for the best method to decoke, looking online people are suggesting all sorts of methods and fluids, some of which seem very inaprotiave (e.g. scrape off with a knife). Best I have found so far so far seems to be toothbrush on a drill with either white spirit or brake cleaner.

Check the valve guides for wear too as well as the valve stems.

What am I then looking for or will it be very obvious? Is the guides the test where you withdraw the valve halfway and check for movement?

It's a pity a compression test wasn't carried out before the strip down.

It was suggested to not bother with a compression test and just pulling the head would tell you all that was required.
 
Yes Piston 1 looks to have a contact mark and that is the one which can be seem exhausting out of the intake in the video.



I am assuming that in order to do this I need to first carefully remove and inspect them as suggested by @jamesmartin before decoking and lapping back in. Any suggestion for the best method to decoke, looking online people are suggesting all sorts of methods and fluids, some of which seem very inaprotiave (e.g. scrape off with a knife). Best I have found so far so far seems to be toothbrush on a drill with either white spirit or brake cleaner.



What am I then looking for or will it be very obvious? Is the guides the test where you withdraw the valve halfway and check for movement?



It was suggested to not bother with a compression test and just pulling the head would tell you all that was required.
various wire wheel heads on a drill and some brake clean the ports dont need to be spotless just mating surfaces and no loose stuff that could drop between them
bench grinder with wire wheel is ideal for valves, to check guides you hold valve just proud of head and rock side to side and flat sharp blade is ideal for the head,finding the area of blow by is first priority
upload_2018-12-5_11-55-13.jpeg

33270g_02.jpg
 
I mount the valves in a pillar drill for cleaning, it's great for decoking the heads quickly.
 
finding the area of blow by is first priority
Completely agree, my plan is to give it a quick clean to remove the loose debris and then to remove the valves one cylinder at a time. I will check each valve to see if it was causing the blow by and clean the the valve and the cylinder head. I will then regrind, and refit the valves before moving onto the next cylinder.

While doing this process what else is worth replacing. I know on older vehicle fitting new valve seals, valve springs, caps etc was done as a matter of course are these still needed on newer engines or can they all be reused with no problems?
 
Completely agree, my plan is to give it a quick clean to remove the loose debris and then to remove the valves one cylinder at a time. I will check each valve to see if it was causing the blow by and clean the the valve and the cylinder head. I will then regrind, and refit the valves before moving onto the next cylinder.

While doing this process what else is worth replacing. I know on older vehicle fitting new valve seals, valve springs, caps etc was done as a matter of course are these still needed on newer engines or can they all be reused with no problems?
just the stem seals and any damaged parts you find
 
Completely agree, my plan is to give it a quick clean to remove the loose debris and then to remove the valves one cylinder at a time. I will check each valve to see if it was causing the blow by and clean the the valve and the cylinder head. I will then regrind, and refit the valves before moving onto the next cylinder.

While doing this process what else is worth replacing. I know on older vehicle fitting new valve seals, valve springs, caps etc was done as a matter of course are these still needed on newer engines or can they all be reused with no problems?
Fit the valves all together when you've given the head its last final clean. Just poke them one at a time through some card with cylinder number wrote on it. Springs etc should be measured but can be reused, replace stem seals though, tappets etc can be reused if the case hardening hasn't broken through.
 

Similar threads