Discovery II head gaskets

[rgallant]

Gasket kit arrived and it time to get started

Symptoms - in case someone else has the same


Although temps are normal I was losing coolant after driving for several hours.
About 1/2 inch loss after 2 or so hours of driving
Coolant loss appears to from the expansion bottle overflow line.
I verified this a bottle attached to the overflow line to capture any coolant from there.

Status
System holds pressure
While driving temps between 188 and 194 - 1600 to 2300 rpm 20 to 55 Mph
Idle at traffic light 197 to 201 depending on how much stop and go drops as soon as rpm increases
Will reach 201 after highway run at traffic light drops immediately once moving
Hoses remain soft at 194 -197 degs
System has pressure in the morning normal pfft noise
No air at bleed screw
Engine Warm up appears to be normal not excessively fast
No misfires or codes
No excessive smoke of tail pipe


1st up was building a shelter

https://i.imgur.com/59UGadZ.jpg


https://i.imgur.com/rZVY47A.jpg

Confirmation of the problem


https://i.imgur.com/xhXAALU.jpg



Martin if these images are too big let me know and I will resize them down.



Garage end is screwed in the house above the garage - just an extra repair job 

With that out of the way I drained the coolant - after 2.5 years it was time and I wanted to get rid of the dexcool anyway for simpler logistics it is hard to find dexcool in the back end of nowhere green is easy

I then flushed with water just to have a solid starting point no crud and good water flow out of the hoses

Then the fun part I started removing all the bits required to get the intake plenum off, I have secondary air so there are some extras.
The nuts that hold the SAI tubes on are pretty brutal to access, so a bit of reading indicated you can gently move the drivers side bracket to get clearance - and bonus you can which means I can deal with those once the heads are off and they are easy to access.

So far other than having to ask about the coil pack bolts it has been going well.

With luck tomorrow evening I can get the intake off, and possibly get started on the exhaust manifolds. I have done that passenger side and both Y pipe gaskets were done this year so I am not expecting any problems there.

More to follow

[bsa_m21]

Pics are fine Richard. Best of luck with the head gaskets. Hope the block is ok.

[DiscoSlice]

Were doing the same job on the same truck (colour and all) good luck man. i too am done with Dexcool... it really is tough on plastics and gaskets.

[rgallant]

@Discoslice we can commiserate and perhaps help each other out then - and of course because I am working a beautiful sunny day.

Good luck with yours

[DiscoSlice]

Commiserate for sure! Ive only had a couple snags so far.

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Otherwise I'm just waiting on parts...

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[rgallant]

@Discoslice which bolts are those ?

I have learned to hate secondary air plumbing but the intake Plenum is off - pictures and details tomorrow,
Lost a 8mm socket down near the coil packs have to find that too

[rgallant]

So with much cursing of the SAI bracket on the passenger side and pipes at the rear I managed to get the intake plenum clear.

Ideally you want to remove the passenger side SAI bracket and pipes mine were not coming out. So some gentle upward pressure then left pressure got the bracket clear of the studs.
Then the intake was off and clear. Bolts would make so much more sense for those brackets.

The rest of the night was getting the battery out and and misc work in the engine bay.

I did discover a literal mouse/rats nest under the plenum

https://i.imgur.com/qnK5Ekx.jpg


Those pipes make getting the rear bolts out a real joy

https://i.imgur.com/nNSBjS4.jpg


https://i.imgur.com/1LyZiLh.jpg

Valve covers and exhaust manifolds are next

[DiscoSlice]

Two of them are from the bracket that holds the AC compressor and power steering pump to the head, and one of them is a rocker arm bolt. I share your sentiments towards SAI... looks like you’re makin good headway!

[rgallant]

A good nights work although short

Got all the exhaust manifold bolts out without any drama
Removed the alternator, an annoying job that thing is really in there
Removed the Air condition compressor those bolts make the very scary I am going to break noise for about a turn. I took the approach of a little bit of a turn then went around to each of other bolts. Then tighten around the compressor and an another round of loosening finally they turned freely.


Then I rebuilt my shelter too much water pooling up there

Brackets and fuel rail hopefully lower intake tonight.

No engine pics but my shelter is nicer - I may have a garage addon by the time I am done at this rate


https://i.imgur.com/cEMKhxj.jpg

[ANDYD]

Hi Richard, sounds like you're going to be up to your elbows in it for a week or two :shock:

Steve Dillen is on the forum and he did his Disco 2 a year or so ago, so you may want to contact him with any questions or motivational inspiration. His forum user name is sdillen

http://roverlanders.bc.ca/roverforum/vi ... 396#p26396

If you get good at this you can likely do one a week for other members, as all Disco 2's seem to need doing after 150,000 kms (or sometimes less) :roll:

Good luck, keep us updated with photos and inspiration
Cheers
Andy

[rgallant]

Thanks Andy, advantage to working from home I can start right after work for a few hours every night. So far is has been not bad, the week the heads are in the shop, I will be replacing a ton of rotten wiring loom it just crumbles when you touch it

[rgallant]

Short night tonight finished at 7:30 rather than 8:30 :

• Cleared the all the pulleys
  Removed the Alt bracket
  Removed the Compressor bracket
  Removed the 2 cooling system pipes from the lower intake - they are a mess literally someone went to town with sealant
  Removed all the fuel injector wiring from the injectors
  Loosened several of the lower intake bolts man those were easy to turn 3/8's ratch and no real effort
  Realized I will have to remove the damm aluminum secondary air pipe to get the coil packs out easily and the one rubber hose does not want to release

I have the day off tomorrow and hope to have the heads off by the end of the day basically I have

• Remove the coil packs
  Clear the wiring harnesses
  Clear the remaining cooling system hoses on the right side
  Remove the fuel rail
  Remove the upper intake so far seem like the easiest thing
  remove the valve covers
  remove the rocker arms
  remove the heads
  remove SAI pipes from the head
  Heads to machine shop with luck

Seems doable in 12 hours

Any weirdness in there other than the fuel rail connector

Any recommendations for a valve grinding, seals will be done
Where to find head specs re decking (truing for us old timers) max limits etc

Valley gasket has seen better days

https://i.imgur.com/hYFwa2I.jpg

A wee bit of sealant in use

https://i.imgur.com/nxEwEbg.jpg

You can see the remains of wiring loom, some of that to replace too

https://i.imgur.com/VEgt8Of.jpg

[DiscoSlice]

I was able to leave my fuel rail and injectors intact on the plenum with no issue. I just slid the whole thing forward slightly to get at that fuel connection

My heads are both true and fairly clean so I’m opting out of a machine shop. Can’t help you much there.

I re-wrapped most of my engine bay harness too, learnt that some new wiring harness protector is Soy based. And can be a rather welcoming snack for vermin! Speak to some new Toyota owners on the coast and they’ll tell you their nightmares.

[rgallant]

@Discoslice lovely soy based wire protection well I have had 1 rat in there so I will need to source something better

[rgallant]

Fast update heads at the shop at 4:00 8:00 to 4:00 with about 1.5 hours of break/tool runs.
No drama getting bolts off etc, a bit of a twist in an SAI pipe.

The gasket fault -this is a wild ass guess appears to have been the left front. When I loosened then removed that lower bolt water started leaking out of the bolt hole, no other bolt exhibited this issue. Due the the gasket issue noted below it is impossible to tell for certain.

Looks like a spray gasket seal may have been used on the head gaskets - they came off wrecked - pics and full update to follow.

[rgallant]

Well got the bad news today heads are done 15 thou out, which leaves me with 2 questions

I am assuming blocks do no warp - am I right there
And anyone have a set of 4.0/4.6 heads with secondary air or a set without and an ECU

I have the last days work and photo's coming and I did find the source of the gasket failure pictures to follow

[ANDYD]

Hi Richard,

Although I'm admittedly no expert on Disco engines 15 thou doesn't sound too bad, is it for sure scrapping the heads time?

Can the heads be skimmed and then maybe a thicker composite gasket?

Not sure about the block warping, that is a question others maybe can answer.

Cheers
Andy

[DiscoSlice]

That is bad news indeed but i certainly wouldn't give up on those heads just yet. The possibility to bend a block does exist, as a general statement. Highly unlikely here though. I would be curious to at least check their diagnosis. I will go back through the RAVE and see what the list for measurements, will try and contact the guy in Calgary that the rover shops use for machining and see what he says.

[rgallant]

I have had several offers for heads so I think I am going to be good - it is surprisingly relaxing and satisfying do this work even with the hiccup of the heads.

My bet it was a torque related issue a couple of head bolts were way too easy to break free - 1/2 ratchet and no real force easy

[DiscoSlice]

Hope you can find some 4.0‘s and an ECU!

[rgallant]

The final bits of disassembly a little of of order but here we are

Thursdays saga cue nordic music

I took the day off work to get the rest of work done to get the heads off

Remove the coil packs - I have mentioned how much SAI makes everything harder. 1st order of business was cleaning up the wiring and coolant pipes on the right hand side so I could remove the SAI aluminum pipes.
Once those were out of the way I discovered a breather line that was tucked downward beside the transmission - not ideal
Got the coil pack up top but while removing spark leads several ripped the ends off bad words were said. but I got it off and into the garage.

https://i.imgur.com/DLqL15W.jpg

4 out 8 ended up this way very annoying, it took pliers in the end to remove them

• Clear the wiring harnesses
  Clear the remaining cooling system hoses on the right side

These were very straight forward and just required suitable use of zip ties and a bit of thought but lots of repairs to do the wire wrap is pretty rotten.
Remove the fuel rail
Remove the lower intake so far seem like the easiest thing
Removing the bolts from the lower intake was very simple as all the inner bolts were just over hand tight, they were also covered in a white pasty substance almost like a grease, You can see it in the image below.
I decided to leave the fuel rail in place, but disconnecting from the fuel feed was dead simple.

Slide the lower intake forward a tad
Compress the silver metal tab push slightly forward then pull back
And done

https://i.imgur.com/BdDKRPF.jpg


Remove the valve covers - no drama here but I did have to go and buy a 12 point 8mm socket and the covers are some filthy. And the passenger gasket was starting to crack.
Picked up a set of NKG spark plugs while I was at it.

Remove the rocker arms once again zero drama, 3/8 drive ratchet and 14mm socket and off the came -with mandatory creak that sounds just like a bolt before it breaks.
A tip here start at one end give the bolts about a quarter turn, then do the other end followed by the center 2, repeat until they spin freely worked really well for me

Remove SAI pipes from the head
While I was out buying a 8mm 12 point socket I picked up a 27 mm wrench a cheap one.
I liberally hit the unions with penetrating oil the night before.
27 on the big nut and an 18 on the inside hard whack with the palm of my hand to get it moving 3 out of 4 not problem 1 twisted a bit - picture below.
What makes this such a pain is there is almost no room for the 18mm, pulling the exhaust manifold completely would give you more room but not much what you really need is a short open ended 18mm

https://i.imgur.com/ptjRnAS.jpg

[rgallant]

Removing the heads - this was not hard all the bolts came free without issue. A couple of whacks with a rubber mallet freed the heads, BUT the gaskets were stuck to both the heads and block and it took a fair bit of pulling and wiggling to free the heads.

When loosing the bolts take your time it is only about a 20 minute job to get them out.

• Print the torque diagram from the the RAVE - you are going in reverse order outside to in
  16 mm socket deep and standard as well a a good breaker bar a 3 footer is a good size
  When 1st breaking the bolts loose 1.4 to 1/2 a turn only to start
  Then keep going in 1/2 to 3/4 turns following the reverse torque sequence until everything spins frees
  Then pull them out

I found some the inside ones in particular very easy to get turning as compared to the bolt on the end
As noted above you may need to give the head a whack or 2 with a rubber mallet to get moving strike the end and the intake side
While pulling out the bolts watch for water /AF leakage there should be none until you free the head enough to start lifting - I had water from the drivers front lower bolt as soon as I had 1 turn not a good sign


Fault diagnosis is difficult as the head gasket lost a lot of material during the head removal process and got pretty bent as well. However I did find a hairline crack all the way through the gasket from fire ring to the cool passage on the drivers side front cylinder.
This crack does not appear to damage from removal as it goes right through the underlying metal. But here are some images

Left side

https://i.imgur.com/q4L7hfy.jpg

right side

https://i.imgur.com/4o1GpKs.jpg

Gaskets -note what appears to be the start of combustion gas between the front two pistons

https://i.imgur.com/3gygPZw.jpg

https://i.imgur.com/atPGOqP.jpg

[rgallant]

Failure diagnosis

Cause was a damaged head gasket drivers side front cooling jacket. This damage to the head gasket was a crack in the metal portion of the gasket. See the images below

Overview :

https://i.imgur.com/O84a6D5.jpg

Detail :

https://i.imgur.com/gubkYr2.jpg

[rgallant]

Found 2 sources for SAI heads so I will be good there

And just for reference the max the heads can be milled is 19 thou from new so 15 on an old head is pretty iffy

[rgallant]

New heads into the machine shop 8:00 am today done by lunch, quote they were in excellent shape:

Valves good
Valve seals replaced as the come with the kit
They confirmed no more than 2 thou - the head decked for best mating

Looks like this long weekend I should be able to get her back together, with luck.

Well I have a plan :

Saturday

• Clean the block and bolt holes - this is going in to be a large part of the day. There are large chunks of gasket that need to be hit with gasket remover, and from my testing it is going to be painful and slow.
  Clean all the push rods while I wait for the gasket cleaner to work
  Misc cleaning of other bits
  Fix wiring loom that sits under the intakes and any other wiring issues
  Reconnect CPS - it did not click firmly when I installed the new one

Sunday

• Fit the heads
  Lower intake
  Rockers
  Alternator and PS/Air Con brackets
  Coil packs

Monday

• Everything else
  Top up rad with water only - it will get dumped after warm up
  Oil change - cheap oil it will be dumped after 100 miles max - good filter

Post start plan:

Oil change at 100 miles or a couple of hours of driving, make sure any left over contaminants are picked up and then removed.
Run water only during initial startup,same idea get rid of any left over contamination - I may do a light duty flush if the water looks "off"
Put AF back in

Drive the Disco everywhere to put a few hundred miles on it, and know she is a happy truck