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Cheap enough to treat yours to a new one and drill the old one https://www.lrdirect.com/Parts-by-Model/Range-Rover-P38-Parts/Cooling/Expansion-Tank/PCD000070-Cap/

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RutlandRover wrote:

BrianH wrote:

Your best bet might be to remove the fan and have another look - that way you know its not getting blown anywhere. Alternatively this sort of thing might help

https://www.ebay.co.uk/itm/New-15PCS-Radiator-Pressure-Tester-Kit-Cooling-System-Test-Detector-Set-tools/332521074244

Idea behind that is the same as Chris says above, put a bit of pressure in the system and see if you can detect any leaks that way.

Have you used this kit? It doesn't list Land Rover/Range Rover in the adapter list but does list BMW. Is the header tank on P38s a borrowed BMW item?

I've used a kit I've already got, but had it a couple of years now. Looks similar to that, its in a red case, has the pump and such. I've not tried it on any Land Rover as not needed it there, the coolant leaks i've had on mine haven't needed them, so can't confirm the cap fits. I'd go with the suggested spare cap with a hole drilled into it if you can valve it in some way as you suggest, cheaper!

Doesn't need lots of pressure either - a hand pump like you'd have on a bike would be adequate, the advantage with doing it using just pressure is you can do it on a cold engine so its far easier to trace difficult leaks as you can prod and probe about without getting burnt (or caught in moving bits etc!)

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Gilbertd wrote:

Cheap enough to treat yours to a new one and drill the old one https://www.lrdirect.com/Parts-by-Model/Range-Rover-P38-Parts/Cooling/Expansion-Tank/PCD000070-Cap/

Ordered one from eBay for the free postage, made it slightly cheaper.

BrianH wrote:
I'd go with the suggested spare cap with a hole drilled into it if you can valve it in some way as you suggest, cheaper!

Doesn't need lots of pressure either - a hand pump like you'd have on a bike would be adequate, the advantage with doing it using just pressure is you can do it on a cold engine so its far easier to trace difficult leaks as you can prod and probe about without getting burnt (or caught in moving bits etc!)

I'm going to give the cap with a valve drilled in idea a go. I have a feeling it won't work though. I think drilling through it will cause the cap to permanently vent as if the pressure release has activated. We'll see though!

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I'd think you can remove the bit that sits inside to get round that problem, might take a bit of experimenting to get it right though.

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Figured out how to seal up a coolant cap. You have to cut out everything inside it, flatten it off and then you can see little holes in the lid that vent out through the "fin" shaped bits of the cap. The bits that stick out that you grip on. Filled these with hot glue, cut a disc of thin rubber sheet to sit inside the lid then sealed that with mastic.

Drilled a hole in the top and fitted a motorbike tyre valve. Spent far too long figuring out why it wouldn't pressurise and I could hear air escaping when I tried pumping the bike pump. I'd forgotten to plug the overflow pipe!

Plugged that and it pressurised right up :)

Removed the alternator, AC pump, power steering pump, tensioner, idler pulley and the brackets that hold the alternator and pumps.

Checked the o-rings for the two steel pipes that go in to the engine. They look to be OK to me:

enter image description here

Area around the water pump was absolutely filthy so it got cleaned up:

enter image description here
enter image description here

No obvious evidence of a leak in there.

Nor anywhere else behind the ancillaries:

enter image description here

From underneath with the system pressurised I can see a drop forming:

enter image description here

Despite removing all those bits I STILL can't see where it's coming from! It just kind of materialises at the top of that silver block and drips there. Looks like it's just inside the boundary of the exhaust manifold.

Is the head gasket somewhere in that area?

Took a short video of the engine running after putting back together just in case anyone can hear something not quite right that might point toward head gasket? I've seen people talking about a "helicopter" sound associated with head gaskets going. It's always sounded OK to me but not sure if I'm getting paranoid - is there a slight "helicopter" throbbing in there?

https://youtu.be/lGUtU6I3p_o

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The throbbing you hear is the standard noise you'll get from a V8 as the firing is not even. That alloy block is at the top of the engine block, just below the head gasket joint. The coolant passages run at each end of the heads so it is in the right place for a weeping head gasket at the front. Just because a coolant passage is leaking, doesn't mean the head gasket has failed in the normally accepted way, the idle is far too smooth for that.. The combustion chamber seals have metal fire rings at the sealing point, the coolant passages are in the gasket material with a seam of gasket sealant around them. It's always possible that your engine was built using a gasket that had an air bubble in the sealant.

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Yeah, I've always thought it sounded fine.

Glad to know it's just paranoia!

I suppose the only way to find out of it is the head gasket in that corner is remove everything I did today and then also take off the exhaust manifold to get a look at the joint?

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If you've already ruled out all other water areas the head gasket is where the leak must be coming from. But like you say, I'd be removing stuff to check (stuff that would have to be removed to change hg anyway). HG has one function but that function breaks down to 3 functions - seal cylinders (metal rings), seal waterways, seal oil-ways. The worst way a hg can fail is on metal cylinder rings but if a hg fails in any other way it's still got to be changed.

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Unless you need the car to get to work, i suppose taking the exhaust manifold off to have a good look is about your only next step. At least then you are half way to getting the head off to replace the gasket if that is where it is leaking from.

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The thing with these gaskets , if they’ve had a long period without antifreeze, the gaskets go like a tea bag, I’ve changed many that are non existent around the water ways.
Here’s an example , although this one was on cylinders

https://imgur.com/a/ZljQ1KS

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That's the thing, I do need it for getting to work :(

I'm fairly sure I've ruled out the other water ways. The only bits I can think of that I haven't been able to see are the core plugs but those need the exhaust manifold off too.

Given the location of the drip, is there a chance it could be a core plug?

I'd need to be as certain as possible as to what it is so I can order everything I need ahead of time. I won't really of the option of getting in there and going "oh crap...it's THAT. I didn't order one of those" and having to wait a few days for delivery.

Given that I've not had any over heating issues would it be OK just reusing the heads as they are or do they always need to go away for skimming/checking when they come off?

While I'm in there, is there anything else that makes sense to replace with the heads off?

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That drip is above the core plugs, they are hidden by the engine mounts and one is behind the starter, so below the head gasket seam. If the engine hasn't been overheated the heads should be fine, just run a straight edge over them, the overhaul manual in RAVE says that the maximum warp allowed is 0.05mm. Rather than using stretch bolts, it's worthwhile replacing them with an ARP stud kit.

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Looks like I'm replacing a couple of head gaskets then!

Just working through a parts list at the moment. Got a UK link to the ARP studs? Found a couple of US links showing them up around $300....that might be a bit on the pricey side!

Any particular problem with using new stretch bolts?

So far my list is, all from LR Direct:

Head gasket set (Reinz)
Head bolts (OEM)
Drive belt (Dayco)
O-Rings for the steel coolant pipes (OEM)
Oil filter

From elsewhere:
OIl
Coolant
RTV
Cable ties
Sandwich bags for bolts and a marker pen
Several tins of brake cleaner and lots of rags/wire brushes
Gasket scraper
Emery paper
Multi pack of hose clamps

As the exhaust manifolds have to come off anyway I might pick up a set of new core plugs just because they're cheap and why not?

I might add a new torque wrench to the list. Mine is around 10 years old, had been knocked around a bit and has never been recalibrated. I've no idea how accurate it is these days.

I'm sure I've missed a good few things there, feel free to add what I've missed :P

Next question is...is this vaguely doable over a weekend?

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Rimmers do them, https://rimmerbros.com/Item--i-RB768020 and I think Turner do too but can't find them on their website. The problem with stretch bolts is that they must be made from the exact same spec steel as original so stretch exactly the right amount. Too soft and they stretch too easily and either don't hold the heads down firmly enough so the gasket blows again not long after or break when you give them the last 90 degree turn, too hard and they don't stretch enough so can pull the threads out of the block. Core plugs are much lower down the block so even with the heads off you still won't have any better access.

As long as you don't find you are short of something goes horribly wrong, yes, easily doable over a weekend. I picked up my engine from V8 Developments on the Friday evening. That was a short engine, the block with no heads. Started on it Saturday morning, engine in, bolted up and then fitted the heads with it in the car. Fired it up for the first time about 1pm on Sunday, took it for a test drive, got cleaned up then drove it to Leeds at 6pm. All you have to remember is that it is two old school 4 cylinder pushrod engines glued together, once the inlet manifold is off, treat it as two engines.

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Those are a much better price!

Do they install and torque up the same way as the regular bolts, as instructed in RAVE?

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I believe this is the correct instructions to follow

https://arpinstructions.com/instructions/157-4301.pdf

You probably also want this > https://rimmerbros.com/Item--i-RB7680L

Does your head gasket kit also include the valley gasket?

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The ARP instructions won't open for me but no, they don't torque up anything like the stretch bolts (as they don't stretch). If the engine was out of the car you'd screw the studs into the top of the block then drop the gasket and heads on but with the studs in the block and the engine in the car you don't have enough space to get the heads on. So put the gasket and heads on without the studs in place, screw the studs in using an Allen key in the hex hole in the top (after you've made sure the holes are clear of coolant, oil and muck before putting the heads on), then lube the washers and nuts and torque them down like normal. As the instructions won't open for me, I don't know what torque they recommend. I've seen people talk about 80ft/lb which seems too high for an all alloy engine to me. Ray at V8 Dev told me to use 65ft/lb so that's what I did. 3 stages, 30, 50 and 65.

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Link is the instructions linked to from here > https://arp-bolts.com/kits/ARPkit-detail.php?RecordID=4560

25/50/70 is whats shown there. Plus the order, though would expect thats the same as in Rave anyway.

Theres something odd happening with some of the links here, as I can't open the one Chris posted earlier in the thread either.

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That's strange. I can open the one Chris posted but not the ARP instructions. On this forum for me links normally open in the same window (which is a bit of a pain as I can end up wandering off on a tangent and losing my way back to the forum) but if I right click the arp link and select open link in another tab, it does but all I get is a blank page. Probably something to do with different browsers, pop up blockers, etc. Firefox V62 on Windows 7 using a popup blocker and Ad blocker too here.

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BrianH wrote:

I believe this is the correct instructions to follow

https://arpinstructions.com/instructions/157-4301.pdf

You probably also want this > https://rimmerbros.com/Item--i-RB7680L

Does your head gasket kit also include the valley gasket?

I'll add that to the parts list.

I was getting the Reinz kit from here.

The image at the top shows the valley gasket, rocker cover gaskets, head gaskets and a bunch of seals. I'm assuming that all the kits listed include the same parts, just of different brands. Confusingly, the description at the top says that it's a head gasket set but doesn't include head gaskets even though they're in the image...

Both links open for me. I'll print the instructions to keep them handy.