Cylinder Head Removal

[Funkshen92]

Hey guys,

I'm currently in the process of removing the cylinder head from my 2010 D22. I took the vehicle to a Diesel Mechanic and was told that there was exhaust gasses present in the coolant system. Having done some research (and after reading their quote) I've decided to have a crack at fixing it myself. I've printed out the relevant service manuals and am working from the Haynes D40 and R51 Service Manual (with a fair amount of cross referencing for any discrepancies). I do however, have a couple of questions if anyone has any experience doing this before, especially considering the most mechanic work I've done before this is changing oil.

The car has just under 200,000 on the clock so while I've got the thing half apart I was thinking of replacing some things that might be worn out/due for changing. Here's my list so far.

Water Pump
Thermostat
Timing Chain (Dual Chain)
Intercooler (old one is leaking)
New Belts
Radiator

Considering I have to take the injectors out I was also thinking of sending them away to get tested.
Is there anything else you would recommend either replacing or inspecting?

I also spoke to a guy from a local workshop while ringing around for crack testing quotes who said that due to the head being aluminium he recommends just replacing the head if its cracked and that anyone saying they can recondition it is talking trash. Thoughts?

Also, is there anything specific I should take note of before starting/during the job?

Thanks for any help

 

[Old.Tony]

Welcome to the forum.

Plenty to be aware of, the manuals should have covered all the important stuff. Taking your time is important, these engines have some expensive parts (the pump is like $4K on its own). Mark things, take photos before disassembly, and most importantly don't disassemble the thing on grass, you'll never find that washer you dropped (hint: it's under the centre where it's hardest to reach).

You will need a torque wrench. Estimating is not sufficient, these diesels have high compression engines (around 16:1) and they need to be torqued properly in order to work smoothly.

Otherwise, it's a good experience. Get the fuel tubing done properly, it has to withstand pressures up to 24,000psi (no joke). You could send the injectors for a sonic cleaning, that's not unreasonable. They do seem to respond well to products like Liqui Moly Diesel Purge. Ask the injector place if they have any issue cleaning piezo injectors.

While you're stripping it down like this: consider adding a catch can (to reduce the oil vapour entering the intake manifold) and consider blocking the EGR valve (to prevent diesel soot accumulating in the intake manifold). When you look inside the intake manifold you'll understand why.

 

[tweak'e]

with such low km's i would be wondering why the head has cracked.
most common is due to overheating, so replacing water pump and radiator would be the first thing.
also intercooler, as any air leak means the engine runs richer (which is bad).

you will need torque wrench and also turn gauge for doing head bolts. head bolts are not reusable.
injection manifold is meant to be replaced each time but generally its ok to remove/refit a few times.

just watch for any catches like sizzor gears that need locking and how timing chains go back on.

 

[Funkshen92]

Thanks for the welcome and the tips gents.

Definitely looking to install a catch can. Was looking at the Provent 200 ( AECO4x4 Provent 200 - D22 YD25 bolt in catch can kit | Ae Co 4x4 ).

Fortunately enough I've managed to wrangle my Pop (retired mechanic) in for the job which has given me access to a torque wrench and a turn gauge. Had a decent enough first day today. Managed to remove the radiator, belts, intercooler and the turbo. The turbo gave me absolute hell, had to remove the exhaust elbow which meant jacking the transfer case and removing the sandbar so the exhaust elbow could drop. An hour later working on a rounded bolt and we got it out.

with such low km's i would be wondering why the head has cracked.
most common is due to overheating, so replacing water pump and radiator would be the first thing.
also intercooler, as any air leak means the engine runs richer (which is bad).

you will need torque wrench and also turn gauge for doing head bolts. head bolts are not reusable.
injection manifold is meant to be replaced each time but generally its ok to remove/refit a few times.

just watch for any catches like sizzor gears that need locking and how timing chains go back on.

When you say injection manifold do you mean the intake manifold or am I missing something?

I've attached some pictures of todays progress if anyone is interested.

 

[tweak'e]

When you say injection manifold do you mean the intake manifold or am I missing something?

fuel injection rail.
because of the extreme high pressure of common rail injection, all high pressure pipes are typically changed. however many do not and its typically ok to do it a few times. eg toyota has a limit on how many times you can do it and the pipes get marked each time its taken off (due to the injector washers being a service item on certain toyota engines).

 

[tweak'e]

actually before you go to far, pull the egr cooler off and get it pressure tested. they are known to fail on a lot of engines.

 

[Funkshen92]

actually before you go to far, pull the egr cooler off and get it pressure tested. they are known to fail on a lot of engines.

The diesel mechanic that spotted the problem told me that they bypassed the EGR cooler when doing their testing and the problem was still present, so am I safe in assuming the problem isnt there?

I got the vehicle at 150,000 in pretty good condition so here's hoping this will be the first time the injectors have been removed.

 

[Funkshen92]

Alright guys, it's been a busy few weeks.

I'm quite a bit further down the road now and I've stumbled into my first road block. The new head is installed and I'm just buttoning up the last of the rest of the rebuild. I've reconnected the Injectors (tests came back good) and the common rail as well as the rest of the left hand side of the engine but the fuel system doesn't seem to want to prime. The Primer on the fuel filter will take about 3 or 4 pumps before going hard but then after around a minute it will go back to being soft again. Any thoughts?

I pressure tested the return fuel line before replacing the valve cover and it showed no signs of a leak. All the fuel pipes were torqued in order and all other relevant fuel lines are attached.

 

[tweak'e]

primer sounds fairly normal. as long as fuel is getting up there it will be fine.
the was a mention of a few tricks to help ensure the injection pump gets fully primed. can't recall which thread.

fuel return line should always be tested under vacuum (as shown in the manual) because some leaks tend to close up under pressure.

 

[Funkshen92]

Alright that sounds promising. Sorry about that, it was a vacuum test I did using one of those handheld vacuum pumps, it held 60''hg which is what the manual wanted.

Still waiting on a couple of locating dowel pins from Nissan (useless mob these guys are) for the primary timing cover chain, so once those arrive I can button up that, pop the cooling system and drivebelts back together and see if she runs.

 

[Newnav100]

Alright guys, it's been a busy few weeks.

I'm quite a bit further down the road now and I've stumbled into my first road block. The new head is installed and I'm just buttoning up the last of the rest of the rebuild. I've reconnected the Injectors (tests came back good) and the common rail as well as the rest of the left hand side of the engine but the fuel system doesn't seem to want to prime. The Primer on the fuel filter will take about 3 or 4 pumps before going hard but then after around a minute it will go back to being soft again. Any thoughts?

I pressure tested the return fuel line before replacing the valve cover and it showed no signs of a leak. All the fuel pipes were torqued in order and all other relevant fuel lines are attached.

I had the same problem after replacing the head. I ended up using a rah and a comporessor into the fuel tank and backing off one of the nuts until there was no more air coming out .

 

[Funkshen92]

She lives!

Buttoned up the last of it this morning and got her running. Fuel pressure was a non issue, it cranked over for about 10 seconds before roaring to life. Definitely sounds a lot better than before which I'm putting down to the upgraded timing chain and fresh belts. Running well so far, even seems like I've gained a few horses due to the replacement intercooler no longing leaking.

Still got a few fluids to change out (clutch and power steering) but at least I can drive to the shops to get what I need now. It's been one hell of a learning experience to say the least (and only three snapped bolts the whole way along). Ended up costing about $5000 all up for parts, tools and sundries which is a damn sight cheaper than the $14k I was quoted from the mechanic.

Thanks for all the help

 

[tweak'e]

good to hear