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Joined: Dec 14 2018
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OK- O rings replaced and not leaking, received my Nano, the wood trim is coming along-applying the matte finish, and now I am trying to decide if I should just go ahead and replace the head gaskets.

I am on the fence- I feel that I am losing too much coolant at idle after burping the system three times for it not going to the cylinders. I am dripping lots of water under each exhaust pipe exit-- I mean a big puddle on each side. I know when I first drove it when the temp was below freezing there was a constant cloud of water vapor-- but when driving it - in about 1 mile went away- then came back when I was at idle to drive it into the garage. Many say that their 4.6 blows condensation -but does it leave puddles on your driveway on each side? To me- new to LR's--this points to head gaskets since I cannot find another leak.

I refilled the coolant after the O ring replacement and can only burp it in the garage by running it up to 2500 rpm and holding since I do not have it tagged- and there is heavy salt on the roads up here in the mountains. During this, the temperature needle stays just left of 12:00. But after three cycles of this, I have to keep adding coolant to the expansion tank. I was hoping that the system was hard to completely bleed out without driving it. But after three cycles and still having to add about 3/8" of coolant each time to get it up to the cold mark-- I am starting to think my head gaskets are leaking.

Normally I would do a leak down and watch air go into the coolant tank-- but bumping this motor to TDC at each piston to do the leak down is a pain-- let alone screw in without cross thread into the spark plug holes. I had to go into my ZEN mode to "feel the threads" on a number of them.

Aside from adding coolant-- my big symptom is that at idle in the garage, I am dripping lots of water under each exhaust pipe. I have puddles after 20 minutes at idle.

I changed out the plugs which looked like they were in many many miles with the gaps about 50 thousands. As you know- a real pain to pull out- the threads were slightly rusty with no grease or anti-seize applied. I have seen slightly rusty threads before so I am not thinking steam.

They all looked pretty normal-- a bit of black carbon- light brown electrodes, but at the bottom side of each ground lug facing the piston, they were light white. I have not seen this before. I expected if there was a water leak then at least some of them would be steam cleaned of any black carbon. Not sure the white is a sign of most cylinder leaking.

Sooo - what is the normal series of tests to confirm--- besides a leak down? I have a radiator pressure tester- but no way is it set up for the cap used on the RR expansion tank. I could buy one off of Ebay and insert a Schrader valve-- but is this worth going down that road?

If I do just dive in and replace the head gaskets just to baseline the motor- are there any special tools which make the job easier? I have a 32 mm fan clutch removal tool- soon to get a 36mm tool for this job. I know the heat shields will be the first big pain-- any tools that make it easier?

I also know that the secondary air tubes will be a huge pain. I attempted to remove them to get a clear shot at the spark plugs but the nuts would not budge. The angle of attack is miserable for the back ones. Do most of you remove the heads with the tubes installed?

I assume APR studs- have not heard a downside except for cost. With China making so many aftermarket bits-- who do you trust to have a good head gasket kit?

Anyone have had the same symptoms --go to replace the head gaskets ---and find they were not the issue?

Thanks-- been through many of the treads-- seems like each head gasket replacement is a challenge unique to each owner and P38.

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Joined: Dec 30 2015
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Methinks you worry too much..... From what you describe I would say it is pretty much certain that you do not have a blown head gasket. The coolant passages run at each end of the heads so a blow between cylinders 1, 2, 7 or 8 into the coolant passage would cause a loss of coolant. However, it would also cause the spark plug in the offending cylinder to be steam cleaned and it would likely drop to 7 cylinders at idle. It would also pressurise the cooling system to the point that it would spit all the coolant out and overheat within 10 minutes or so of running. The only other way of coolant getting into the combustion chambers is around the outside edge of a liner but again, you'd be seeing cleaned, if not rusty, spark plugs and pressurising to the point where it would blow coolant out of the overflow if not start bursting hoses. So, the black carbon on the plugs says you don't have coolant getting into a combustion chamber either through a gasket or a weeping liner.

In cold weather you will get puddles under the tailpipes. If you are feeling really brave, dip your finger in it and taste it. If it tastes of anti freeze, then it is coolant but I suspect you'll find it doesn't, it's almost certainly condensation.

Fortunately, we don't have the secondary air injection system, that is only fitted to US spec cars, so plugs are fairly easy to get to. and they don't get in the way when it comes to taking the heads off.

There are numerous 'recommended' ways of burping the cooling system that have varying degrees of success (reading some of the threads over on the other forum, you'd think it was some sort of black art). I have never had to burp a cooling system, I just fill it up but I do have my own way of doing it. Disconnect the bleed hose from the top of the radiator and poke a piece of wire in to make sure it is clear. Blow through the tube to make sure that, and the small hole into the filler neck on the header tank, is also clear. If you have a blockage in this bleed circuit, you will never be able to bleed all the air out. Fill the header tank to the top, let it settle for a few minutes and keep topping up. Once the level stops dropping, squeeze the top hose, put your finger over the bleed nipple on the radiator and release the top hose. You are squeezing air out of the bleed nipple and sucking coolant in from the header tank. Keep doing this, and keep topping up the header tank if you need to, until coolant comes out of the bleed nipple and refit the hose. If you can hear the coolant sloshing around inside the engine, there is still air in there so carry on until you can no longer hear it. Now refit the hose to the bleed nipple and carry on the squeezing of the top hose only this time put your finger over the hole inside the header tank neck where the bleed hose is attached. A couple more squeezes should see a stream of coolant coming out of this hole every time you squeeze the top hose. Now, and only now, start the engine. The thermostat will be closed so all coolant flow will be through the heater matrix. Raise the engine revs to 1500 or so and you should see the last of the air from the heater hoses bubble up into the header tank. There should also be a constant stream of coolant out of the bleed pipe into the header. Let it idle for a few minutes and there should be no more air coming out so you can put the header tank cap on. Job done.

If you still decide you want to change the head gaskets, an 6 point 8mm 1/4" drive socket may help with the heat shield screws and ARP studs are definitely worth it. No need to remove the fan and viscous coupling so you won't need your 36mm spanner either.

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Joined: Jul 12 2016
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For bleeding my coolant system all I ever do is remove the thin pipe from the radiator and blow down it to clear it. Then I fill the expansion tank, run the engine and let it pull the coolant through and keep topping it up.

Sometimes it will bubble and overflow so I turn the engine off, let it settle and top it off again before running the engine.

I keep doing that until the level in the tank stops dropping and I have heat in the cabin.

As for identifying a blown head gasket letting coolant in to the cylinder is to check for steam cleaned plugs. When mine went it was different - it was leaking coolant OUT of the engine and down the side of the block. I found that by pressurising the system.

If you do replace the head gaskets the exhaust heat shields are a right pain. I had to break mine off, almost none of the fixing were able to be removed and it took ages to get them off. I was told that when putting them back on the fixings sound the edge aren't really needed but I wanted to use them anyway. I had to hammer the shields back in to shape and fit rivnuts to join them together.

The bolts for the rocker covers use a special bit to undo them. IIRC they're a 12 point spline type thing. None of the 6 point sockets I have would work. I had to borrow the correct bit from Gilbertd. I replaced them with new bolts with a different head.

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Joined: Dec 30 2015
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True, I forgot that one. The rocker cover bolts are 8mm, 12 point and on earlier cars (not sure about later ones) the exhaust manifold to head bolts are 12mm 12 point.

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Joined: Jul 12 2016
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Yeah, my exhaust manifold bolts were 12 point too

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Joined: Dec 14 2018
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Gil, Rutland-- thank you for your experienced observations.

From what you both say- probably a very small chance of head gasket leaking based upon the condition of the plugs and it appears that the reservoir is not being pressurized enough to be pushing coolant out the overflow tube.

If I had not read over and over how these motors eat head gaskets I would probably not even thought about them as an issue. Problem is-I never had a car which pushed out so much condensation-- that is what has spooked me about possible head gasket leaks even though I have no other symptoms other then the coolant level continuing to drop each heat cycle.

On my race bikes- if I had a leaking head gasket I could always tell because the coolant overflow bottle would pressurize and spit out coolant-- which does not seem to be happening in this case. But that bottle was after the pressure cap- the cap would have to unseat and push water and gas into the overflow bottle so it was a 100% indicator. With the pressure cap on the reservoir and it being only 2/3rd filled when cold, I was not sure if it reacted the same way to cylinder leaks --pushing coolant out of the overflow tube

As far as bleeding---When I first bled the system I did blow through the thin plastic radiator to expansion tank hose to clear it. I squeezed the hose near the expansion tank- but I did not continue doing so as you suggested. If the coolant keeps dropping then I will work that hose more. When I shut off the motor I do hear coolant gurgle in the block. The temperature needle was running straight up at 12 but now it runs just left of it- which I take as a good sign.

Ok-- will check this off my list of possible current issues with my new P38. I am sure there will be other issues to keep me occupied.

Thank you again--- Just too new to P38's so I do not know what I do not know.

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There have been so many old wive's tales built up over the years that most can be ignored. The engine has been around for a very long time and has been used in numerous different cars so if it was as bad as some make out, it would have been killed off years ago. Yes, neglect the cooling system, allow it to overheat and it will blow a head gasket, but so will any other engine. It's much like the stories that the 4.6 will slip a liner at every available opportunity but it happens less on the 4.0 litre. Why? Not because the liner is thinner due to the larger bore (as the bore is the same, it is the longer stroke that gives the increased capacity) as has been suggested but because they sold less 4.0 litre engined cars so less will fail. Much of this has been spread around by RPi who exaggerated the problem to convince people to spend a fortune of their custom cast blocks.

Anyway, the gurgle from inside the block is a sure sign that you still have air in there and until that is out then the coolant level will keep on dropping. Once up to temperature there should be pressure in the system, the hoses should be firm but not rock hard. If it doesn't pressurise at all, then you have a leak somewhere and you won't be able to bleed the air out as the coolant leaking will be replaced with air.

A few years ago the Top Gear boys crossed south America in different vehicles, one being a very rough Range Rover Classic. At the end of it the verdict was that the most unreliable car in the world was the most reliable car in the world (https://www.youtube.com/watch?v=-q-3VK4JgE0).

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Joined: Dec 14 2018
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Gil- good to know.

Yup- still gurgle so will continue to heat cycle and bleed. My hoses pressurize and I can crush them in a bit using my thumb.

Like most forums, the talk often revolves around solving issues and that magnifies the belief that these issues are bound to occur.

Aside from head gasket leaks due to overheating-I do question---if the factory knew that overheating caused liner slips on a percentage of the motors- why did they not pin the cylinders at the factory. Could be that very few cylinder slips happened during the warrently period when most were serviced at the dealer. On my CarFax I noticed that during the first 70K miles that the dealer service the cooling system twice.

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Joined: Jul 12 2016
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MarkTr wrote:

Gil- good to know.

Yup- still gurgle so will continue to heat cycle and bleed. My hoses pressurize and I can crush them in a bit using my thumb.

Like most forums, the talk often revolves around solving issues and that magnifies the belief that these issues are bound to occur.

Whenever I need to bleed mine I do find that the very last bit of air rarely comes out until I actually drive the car. It usually needs one last top up after the first drive then it's fine. I don't know if it's the higher engine speed moving it all round with more force or if it's the motion of the car turning and stopping etc.

And yeah, you'll rarely find a forum full of car people all saying "Hi guys, mine's working fine, hope you all have a nice day :)" lol

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Joined: Dec 30 2015
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Mines working fine.....

(if you ignore the 4 strips on the rear window heater that don't do anything and the front heated screen that only clears a few strips)

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I did say it was rare, not impossible :P