Over heated engine - NOW WHAT - your advice please

**JaapRoskam** · 13th October 2013, 09:18 PM

I would like to ask some advice in fixing a steaming 4.6 in my 1996 P38.
Has done 260000 k. with little service history known.

Had the mis-fortune to let the engine very briefly ... I hope ... overheat last Thursday 10/10 and got to a full stand still, of all places in the Sydney Lane Cove Tunnel, on that stinking hot ( 36 C ) October day. Not that it matters where it happened if not for the somewhat pleasant fact that the Lane Cove Tunnel Company or what their name is came out with a tilt-tray truck , tried to get me going again with heaps of water in the cooling system , after carefully spending half an hour came to the conclusion that the engine would not start.. Then organised a second Tilt-tray vehicle behind us as a safety barrier for the ongoing peak hour traffic and brought us ‘home’ ... all for FREE , so paying toll has its advantages. Thanks guys !

This is what happened:
Just in the tunnel I noticed that the temperature meter was in the red. The small red light in the meter was on. When I saw it I took the first opportunity to stop after 2-4 minutes, I just had finished a long day work and was tired , so I’m honestly not sure about how long the engine was too hot. Maybe only just , maybe a bit longer.
During the time I noticed the overheating and stopping the engine quickly began to loose power. Once stopped I could not start anymore, besides of that I now also had a Transmission Error message on the dash display. I let it cool down for a while , then tried to refill with the little water I had , to no avail , the water boiled out. When the emergency guy came he slowly refilled the cooling system to the top but once filled could not start. Once brought home I tried to start after about two hours cooling time ( me and engine ) but could not get it going.

At this point I need to go back in time a little:
I had the car checked out by Graeme Cooper about 6 weeks before and he had noticed that the Cylinder 8 plug was extremely tight, which to him was a warning sign that the head gasket might be leaking. I just had not noticed any significant coolant loss. But I was already planning to fit a set of fully rebuilt and ported cylinder heads which I had bought some time ago.

Back to now :
Next morning started the engine again with reasonable ease, engine runs great but steams out of the exhaust like a locomotive .
Alto Land Rover in Sydney suggested to disconnect the Cylinder 8 fuel injection to see if that made a change. It makes the engine run rough as to be expected, but the steaming reduced not completely.

This are my observations:

Water in the oil - milky and with fatty globules attached to all surfaces.
Steam out of the exhaust.
Engine runs very smooth.
Disabling cylinder 8 reduces steam out of exhaust a bit.
When the coolant reservoir cap is removed the water bubbles out and smells like petrol / ethanol and exhaust fumes.
Alto Sydney told me that this model engine has 'wet liners' ... is that correct ?

My preparations, I bought:
Fully rebuilt ‘like-new’ ported heads that came off a 3.9 , the heads have .5 mm taken off.
Composite head gaskets.
New head bolts.

Your advice:
Since I never replaced cylinder heads but have done other large mechanical jobs I am not afraid to tackle this job.

But I would appreciate advice from the more experienced ones amongst you.

What to look out for.
What to do.
What NOT to do.
etc.

Any sound advice is welcome guys !!

Thanks in advance and I hope this never happens to you ... again.

Jaap

**bee utey** · 13th October 2013, 09:39 PM

Your heads will almost certainly have warped enough to lose the seal of the head gasket against the water jacket at the rear of the block. However there is a distinct possibility that your block has cracked and one liner or more is therefore loose. The liners are dry liners set into the alloy block but these engines aren't known for their ability to survive a major overheat.

I'd remove the heads and carefully inspect the block face for individual liners sitting below the rest, and signs of water in cylinders 3,5 and 4,6 away from the water jackets. You may just be lucky but many engines that reach this stage are scrap metal.

**Eevo** · 13th October 2013, 10:35 PM

Have a search for top hat liners

**clubagreenie** · 14th October 2013, 12:49 AM

There's a very good chance the liners have loosened. If the gauge is anything like the D2 then it starts moving at 55, is horizontal at 77 abd stays there until 98. From there it's a short trip to the redline and light at 107. You need to get the block tested for hardness as they soften in extreme cases and top hat liners won't fix that. Good news is you have the base oparts for the 4.6 so you only need source a good block and reline.

**benji** · 14th October 2013, 06:41 AM

Most times when the block cracks, the liner will move and you can hear it slamming against the head. Is there any knocking?

By all means pull it down, but you are looking at a top end rebuild if you're lucky, and a whole block if you're not. Depending on your skills Greame Cooper are one of the best in Australia, and there's also another bloke in the western suburbs just off the m4 from memory who is reallly good too.

**peter51** · 14th October 2013, 07:19 AM

It is a complete fallacy that engine liners move - it depends on the engine production date. My engine starts with serial number 59D and the liners cannot move because the bottom of the liner sit up against a recess in the bottom of the block. I can send you photos to show every body.

Google "John Robinson the last word on liner failure" - there is a picture there of an early block that has been laser cut - it shows a small tear in the block adjacent to a head bolt. He also gives lots of information on the usual block issues

First you should look in each cylinder for any coolant after it has cooled down.
Any coolant - its a strip down. If no coolant,then do a leak down test. Before that fill the coolant reservoir. If you have a cracked blocked/head gasket fault then air bubbles will appear in the coolant reservoir.

If you have these symptoms then take the heads off to inspect the head gaskets. If the head gaskets are OK then you have a crack in the block somewhere. So now continue to lift the engine - its an easy job but be careful. Now have the block pressure tested at the local engine shop - or do it yourself - google the forums on how to do it.
If the block is bad - start you research.

**JaapRoskam** · 14th October 2013, 07:20 AM

As far as I can hear it the engine still runs smooth and quiet. No unususal noises what so ever. So after the various dooms scenarios projected I still have hope

**JaapRoskam** · 14th October 2013, 07:25 AM

Google "John Robinson the last word on liner failure" turned out to be a bit of Irish history fun , but I found the link by removing his name i the search:

JE Robison Service — the blog: The last word on Land Rover liner failures - I hope!

Terrific read !!
Thx.

**PeterAllen** · 14th October 2013, 07:43 AM

Are you sure that the heads off the 3.9 are a sure swap? I had asked on here about using bits off my old classic 87 model and was advised that there was a slight difference on the heads. Can't recall what it was but I am sure someone on here will be able to.
If you are looking for an engineering shop to skim the heads, I used a place opposite Bunnings car entry at Northmead. I did mine last year and had the heads machined for $110 per side. Make sure you lay out all the valve rods in order. I made a simple template from cardboard and poked them through small holes in the right order and orientation. Give all your manifold bolts a liberally spray with the wd40 the night before especially the drivers side closest to the firewall ( hardest to get at). Good luck with it. I feel your pain.

**bee utey** · 14th October 2013, 07:57 AM

Originally Posted by PeterAllen

Are you sure that the heads off the 3.9 are a sure swap? I had asked on here about using bits off my old classic 87 model and was advised that there was a slight difference on the heads. Can't recall what it was but I am sure someone on here will be able to.

Late 10 bolt 3.9 heads should be a direct bolt on fit. Earlier 14 bolt heads have some minor differences but not enough to stop a determined mechanic.

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