Changing the "P" Gasket and taking the head off

[SavingTheDefender]

So weeping coolant tells me that I need to swap over the "P" Gasket.

I've also got a long running diesel knock so while the coolant is dropped I'm also going to take off the head to see if there is anything untoward going on inside.

Apart from a workshop manual and torque wrench, are there any other hints, tips, pointers or things I should be looking out for?

[roverrescue]

If you are unsure of the condition it is worth buying three of the long bolts that secure the water pump through the P-Gasket and into the housing. They have a habit of corroding quite nicely and new bolts are cheap insurance. Would probably pay to look into changing up the water pump while it is all apart and getting the radiator rodded.

On a defender the trick that you will quite likely fall for is when your all done and dusted and bolting the head back on, you will forget to install the air cleaner bracket under the head bolts... requiring you to untension and then retension them!
Its quite frustrating. My trick to remember is to put a note with the angle guage saying aircleaner!

Diesel knock can be a myriad of things - pulling the head may or may not reveal all???

steve

[PAT303]

May I suggest removing the gearbox in regards to the engine knock. Pat

[87County]

In addition to the above advice, I was told to have the deck (and the lower surface of the head if reusing it) scrupulously clean before reassembly and it seems to have paid off.

Instead of using grease to lube the head bolts & flanges on assembly, there is now a specific lube for the purpose.

Due to the stretch torquing procedure, many users use new bolts.

If using Permatex Ultra for a water pump sealant allow to set overnight.

[steane]

May I suggest removing the gearbox in regards to the engine knock. Pat

Be quieter if you just removed the engine wouldn't it? Use less fuel as well ;)

[PAT303]

:p. Pat

[jboot51]

Disconnect the battery before removing the alternator


Drain the fluid from the block via the drain bung on the side between the alternator and turbo.


Loosen the water pump and p/s pulleys before you remove the serpentine belt.


release the p/s pump but leave it all connected, just lean it forwards.


Use a metal P-Gasket, there are still paper ones getting around.

[PAT303]

Serious post,change the three bolts,use ultra blue on the gasket,this part is important,make sure you rough up BOTH surfaces with 80 grid sand paper,you want it rough,tighten all the bolts evenly,all of them including the water pump bolts,imagine your torquing a head. Pat

[SavingTheDefender]

Thanks for the tips, although I will be leaving the engine and gearbox in situ for the moment! Gaskets have arrived so all I need now is a lazy Sunday afternoon.

Watch this space!

[SavingTheDefender]

It seems I might not be able to avoid digging in any longer as The D'Fer has started chuffing.

A part of me was hoping that things would hang on long enough for me to cost out a 3.9 Isuzu turbo and LT95 conversion.

The sound is predominately from the front of the engine rather than the firewall end and there are no obvious signs that it is the exhaust manifold.

The oil is not milky, there is no smoke and the power is spot on. So time to nip it all in the bud.

I'll be sure to take and post some photos as things get oily.

[PAT303]

How long has it been since you checked the valve lash caps?. Pat

[wrinklearthur]

You seem to have most points covered with the head gasket changeover, the other thing I would have on hand for a quick job is a good, tested head, in case yours has developed cracks in the metal between the valve seats.
IMHO the cracks seen on most 300TDi heads around the injector ports don't seem to cause any problems.
Price for a head? Depending on the location where you are doing the job, these prices are only a suggestion? :
A recently removed head that hasn't been tested $300.
Price for a light skim, hardness and pressure test add $250.
New head without valves $900
New head assembly with valves $1200.
.

[SavingTheDefender]

So today I've started the pull down. And after a little over two hours work the head is off and ...

... the gasket has gone in three places!

Straight out the front of #1 plus out the sides of #2 and #4 via the head stud bolt galleries.

To add insult to injury one of the little copper washer thingys has also corroded away.

Back to work!

[Blknight.aus]

for any extra if you havent already seen it

http://www.aulro.com/afvb/discovery-1/226962-new-cylinder-head.html

http://www.aulro.com/afvb/discovery-1/227285-mls-torque-angle-settings.html

[SavingTheDefender]

I'm pleased to confirm the arrival at around 2:35pm this afternoon of a bouncing baby 300tdi.

Started first time on the key. New belts and hoses fitted too. The hardest part of putting it all back together was bleeding the cooling system.

New "P" gasket in place and water pump too. The old pump looked good but a little preventative maintenance while everything was apart seemed sensible.

Thank you for all your feedback and words of wisdom. The D'Fer rides again!

[SavingTheDefender]

So it seems that I celebrated a little too soon. The dreaded "P"" gasket is leaking again. I'll try and re-tension today but based on the volume of fluid I suspect I'll need to give it another try.

In better news the replacement center pipe arrived and was fitted on Tuesday. The D'Fer now has a noticeable but not annoying base note. Pick up off idle and low rpm lugging clearly improved. Worth $170? Who knows. The real test will be the first time I strap the camper trailer to the back.

[dromader driver]

on my specifically calibrated hill, i had a pleasant surprise after removing the centre muffler. :)

[SavingTheDefender]

So I'm becoming quite the expert at pulling the front end off my little 300tdi. Very disappointed at the metal gasket which came out warped and uneven. The metal ridge which I assume is meant to assist sealing was not evenly compressed and there was clear evidence that the Blue Hydrostuff had not done the job.

I've upped the ante and gone for Permatex Ultra Copper which is for extreme temperature and pressure. Applied per the instructions and so far, so good!

Thinking laterally I've also ****ed off the P gasket entirely thereby removing a failure point in the process.

Checking the gasket over, it had warped, the metal ridge was uneven and the black paint had cracked. Three points of failure here as a start. Had I not checked both faces for level and torqued the job myself I've have blamed dodgy mechanics.

But when I bled the system yesterday it was a piece of cake compared to the previous nightmare which suggests to me that the gasket was doomed from the start.

I'm now researching the last gasket on my to-do list. There is a rectangular fitting which the rocker cover breather hose feeds into the side of the block.

I've already replaced the gasket on the oil filter housing to block but couldn't go higher thanks to the injector pump and air conditioner compressor. But with the compressor out at the moment it looks an easy task from the top. One of the bolts appears to be extremely rusty so a good soak in WD40 is the go here. Just need to find a part number for the gasket...

Once we're leak free I can get onto the air conditioning refit.

[loanrangie]

So you used sealant instead of the gasket ?, mine is showing signs of weeping so will need to be done.

[SavingTheDefender]

So you used sealant instead of the gasket ?, mine is showing signs of weeping so will need to be done.

Yes, I did. But proceed with caution as I still appear to have a minor coolant leak which means I am about to declare thermo-nuclear war on the 300tdi!

Before I cry and pull it all apart a third time, does anyone have any other tips? Arrrrgh!

[SavingTheDefender]

on my specifically calibrated hill, i had a pleasant surprise after removing the centre muffler. :)

So far I'm just loving the smoothness as she revs and the willingness to pull from lower rpm. Where it used to struggle to pull 4th, the 300tdi is now a happy thing.

[rick130]

Re the P gasket, it's the front housing that warps and won't let the metal gasket seal. ;)

[Jock The Rock]

Yes, I did. But proceed with caution as I still appear to have a minor coolant leak which means I am about to declare thermo-nuclear war on the 300tdi!

Before I cry and pull it all apart a third time, does anyone have any other tips? Arrrrgh!

Best suggestion

https://www.aulro.com/afvb/images/imported/2015/12/904.jpg

Smart comments aside, as Rick mentioned above

The aluminium surface need to be absolutely smicko, I chased dads P-gasket for a while. On the last attempt I touched up the surface with a single cut flat file, it had just started to corrode around the edges which seem to be enough for the gasket to continually fail. Last I checked it wasn't leaking anymore

Perhaps

[SavingTheDefender]

Best suggestion

https://www.aulro.com/afvb/images/imported/2015/12/904.jpg

Smart comments aside, as Rick mentioned above

The aluminium surface need to be absolutely smicko, I chased dads P-gasket for a while. On the last attempt I touched up the surface with a single cut flat file, it had just started to corrode around the edges which seem to be enough for the gasket to continually fail. Last I checked it wasn't leaking anymore

Perhaps

So I was saving my pennies to pick up an engine and gearbox via Greys Online. But the head gasket decided it couldn't wait. I was also looking at a 6BD1T (the 6 cylinder version of what you're teasing me with) but I'm now thinking a twin turbo 4BT might be sweet. Weight is about the same as a 350 Chev but the torque would be ballistic!

She Who Must Be Obeyed has her nose well and truely out of joint at the moment with the truck so softly, softly for a while.

[SavingTheDefender]

So it looks like my ongoing leak is due to a porous casting. Coolant is weeping not from the gasket area but about 2mm in - through the aluminium itself. Must be a hairline crack. Bugger!

Any tips on where I can get a cheap ERR3736?

[rick130]

Bugger, just have to do a ring around.

Maybe All4x4 at Kotara or Land Vehicle Spares at Silverdale for second hand, Karcraft or BMI for new.

It was one of John Davis's mechanics that tipped me off to the housings warping, they see it all the time.

[micksta1973]

A good trick is, if you have a steady hand and a very small ally burr that fits a dremel, very carefully grind a tiny groove in the mating surface all the way around, not on the head though. This gives a place for a bit of sealant to sit in, rather than all squishing out, helping prevent leaks.

mick.

[SavingTheDefender]

Dare I say it... No coolant or oil leaks from my 300tdi.

I know that's a big call but we're looking good. The new OEM alloy casting (the housing for the water pump, which the alternator and the power steering pump also mount to) proved a little problematic as a couple of the holes were not pre-drilled to the correct depth. A couple of washers and some minor file action and I was in the clear.

Call it overkill, but I've used both a new P Gasket and a light smear of Gasket Goo. Not the Blue Hylomar as it quickly failed both on the failed P gasket repair and the water pump housing.

The system bled like a dream. Bliss!