MikeAK

Thanks all for the advice. Haven't had chance to look on here for a couple of day and I pre-empted Escape's suggestion of cutting the metal bracket in front of the heater yesterday. I removed about 5mm in the middle which allowed the two ends to be wiggled out. I probably didn't need to remove any metal, just cutting it would have done I think. Thanks Escape for the kind offer of dash parts, but I had already ordered the lower dash from Ebay before seeing this. Rest of the structure and vents etc. seems OK Once that was out of the way it was easy to wiggle the heater box out leaving the AC evaporator part in the car. I made a small "repair piece" for when it goes back together. Also means future dismantling will be easier if (when) I have to do it again. Once the heater box was out I was glad I went to the trouble. The heater core is very crusty and had been leaking from the seam where the plastic end tank joins the heat exchanger. So a new one required. I then fitted the replacement blend motor and plugged the heater box in with it sat on the centre console to check everything works. It didn't! The blend flaps were OK and moved correctly. But the distribution flaps were very stiff, the motor could hardly move them and frequently stalled. So dismantled the heater box and found that several of the flaps were tight in the bores they run in. Lubricating didn't help so did some measuring and the bores were smaller than the bearing surface on the flaps! Don't know how that's happened, does plastic shrink with heat and time? So carefully drilled out bores slightly larger and everything nice and free until the heater box was full clipped back together when the flaps were binding again. Not as bad as before but still to tight for the motor. This time I found that when box was fully clipped the flaps were binding on the bosses on the central dividing wall. So I slightly sanded the bosses on the wall to relieve it slightly. Now the flaps ran freely, seems like the outer walls of the box were pressing to hard on the shafts. Again is this distortion due to age and heat? Sounds simple but that was over half a day of repeated dismantling, adjusting, re-assembly and trying! Tried it again loosely in the car and this time all the flaps calibrated using Nanocom and could be driven to any position using the diagnostics. Happy days. I should have taken some pictures but I got too involved and forgot until the box was re-assembled. however its all fairly obvious when you have the heater box apart. While I had the Nanocom connected I noticed the heater core and external ambient temperature were way off both around 95C (heater display said external temp 55C so I presume it limits at that) temperature was about 8C at the time and engine not run for a couple of days. That might explain some of the random temperatures coming out of the heater. Both sensors measured randomly varying 150K and 259K ohms with no correlation with temperature (fridge and hair dryer) so they are both duff. Heater core sensor STC3256 and Ambient sensor STC3257 both appear to be obsolete. Hardly anywhere has stock and anywhere that claims to have stock has them listed at ridiculous prices. So I connected Nanocom back up and to monitor temperature readings and resistance substitution box in place of the sensors and to get an idea of the thermistor resistance values and curves. I think I have found some suitable bead thermistors from RS/Farnell that I will have to find a way of mounting. If anyone is interested I will start a separate thread on the P38 HEVAC sensors etc. None of that stops me re-fitting the heater box and and starting to re-assemble the dash so that's tomorrows job. Mike Mike

Hi, After recently getting my P38 rebuilt engine running I decided it was time to fix the leaking heater O rings and and the book symbol on the HEVAC display (fault reported as RH blend motor open circuit). So out with the dash. Fiddly but not as bad as I was expecting. Unfortunately this was the state of the lower dash. Not done by me, it was like this when I removed the centre console facia. And the RH blend motor was like this. Motor and mounting bracket both smashed off the heater and the cable severed. I can only assume the PO or his garage had tried to gain access to the heater O rings by smashing through the RH side of the lower dash then gave up without changing the O rings and causing all the damage. Some people shouldn't be allowed tools! It seems the blue/green mounting bracket is not available as a separate part, but all the bits are there so hopefully I will be able to Araldite it all back together. I have a spare blend motor and a lower dash is on order from Eblag. I think this is the final piece of bodgery by the PO to sort out, but time will tell! The heater pipe retaining plate was screw was seized so I had to drill the head off. plate now sat in a jar of diesel to see if that will free the remains of the screw off. I think the heater matrix is OK but am considering changing it while I have the dash out. I haven't tried yet but it looks like the metal dash structure will stop it coming out. Does anyone know if entire heater will come out if I unbolt it? Looking at it I'm not sure it will clear the metal dash structure? Thanks Mike

Took it for MOT this morning It Passed CO 0.4% HC 32ppm A world away from where it was before rebuild (high CO and 1500ppm HC). Of course being a Land Rover it wouldn't let me off that easily so it started leaking from the heater O rings on the way back! I knew it had a slight leak sometime time in the past because of staining on the carpet, but it's leaking properly now. So that's the next job, not too bad as I had to get to the heater anyway to change a faulty blend motor. Wonder what it will be after that... Thanks again Mike

At last! Got it running today. Started straight away. Took me by surprise, I was expecting a bit of cranking. Ran it at 2000rpm for 5 mins with the wife looking for any major leaks, then switched it off and had a proper look round for leaks. Fortunately there were none. Then ran it again at 2000rpm for another 15 mins to finish off bedding the cam in. Very happy with it, it's much smoother than before and the idle is much more stable. Must be the longest engine rebuild ever! Started looking at it in August, although didn't pull the engine out till November. I blame painting the garage floor, lockdown and the weather! Booked in for MOT on Wednesday, so fingers crossed. Thanks to every one for advice and encouragement. Mike

Thanks all, having done some more reading it seems anything between 2000 and 3000rpm for 20 mins should be OK. It's not allowing it to idle that is the critical thing. I am using this oil from Smith and Allan. Although it doesn't say on the website I emailed them and it has a ZDDP content of 1300ppm and is ideal for older flat tappet engines. I also used high zddp assembly paste on the cam and followers. Snowing again today so delayed again Grrrr. thanks Mike

After being delayed yet again by the weather (I'm too old for lying in the snow under a car!) but the engine is back in now just the ancillaries to fit. So if the weather co-operates it should be running tomorrow/Saturday. I'm trying to remember the cam bedding in procedure, there's nothing in rave. I seem to remember something like vary between 2000-2500rpm for 20 minutes. Does that sound right? Thanks Mike

James It will be getting new cats when it all goes back together. Delayed again, life keeps getting in the way! Engine nearly ready to go back in now, put on the rockers on today and checked the tappet preload. It was around 70 to 85 thou across all the valves. Interweb suggests 20 to 60 thou is the range to go for, so I have ordered a shim kit. Depending what I can achieve with the shims is it better to go towards 20 or towards 60 if I can't get mid range? But why does it matter? Tappets have a range of about 100 thou (4mm) so as long as say 10 thou is allowed at each end for a bit of headroom that gives a range 10 to 90 thou. So the tappet would not be loose or binding and would pump up to take out the slack unless I am misunderstanding, comments from a grown up would be appreciated. Some advice says that at preloads above 60 thou the tappets can excessively pump up and hold the valves open at high (>5000rpm). However this engine is in a Range Rover not a race car, so again does it matter? Thanks Mike

I didn't actually speak to Turners about the conrod cap bolts, but went off this on their website ERR1772. Scroll down below product description. Mike

I used new big end bolts, £3.60 each so £58 ish for 16. Not cheap but cheaper than having a used one let go. All back together now apart from tappets pushrods and rockers. Will finish tomorrow then I just need some decent weather to refit it. I also used ARP suds and nuts for the heads, way better than the stretch bolts. Mike

Didn't get back onto rebuild this weekend, but back on this afternoon. Started checking crank dimensions before re-assembling and got very confused. Are the imperial dimensions for the mains in the engine overhaul manual (attached) complete bobbins or am I having a senior moment? The manual has metric dimensions of standard 63.487 to 63.500 mm and imperial 2.499 to 2.52 in min regrind size 62.979 to 62.992 mm and imperial 2.509 to 2.510 in 2.509 is bigger than the minimum standard size! Converting from the given metric dimensions myself I get imperial standard of 2.4995 to 2.5000 in and imperial min regrind size of 2.4795 to 2.4800 in which makes sense as 20 thou is min undersize. My crank was machined to 10 thou undersize and measures 2.4897 in within 0.0002 in across all the mains which converts to 63.238mm which is in spec for a 10 thou (.254mm) undersize 2.4895 to 2.4900 in or 63.233 to 63.246mm according to my conversion. Normally I would have worked in metric but only had an imperial micrometer available so was looking at the imperial dimensions and got confused. Am I missing something or is the manual wrong? Mike 4.0 & 4.6 Litre V8 Engine Overhaul Manual (LRL0004ENG - 4th Ed).pdf

Ordered big end bolts and a load of other stuff from Turners today (bit of a wallet bashing!). As you say not worth risking re-using for the price. Picked up block and crank from machining this afternoon, so should be able to get on with re-building this weekend. Mike

Should be getting block and crank back from machining later this week, so getting everything together to start rebuild. In the engine overhaul manual it says the con rod bolts (ERR1772) are angle tightened (similar to head bolts) but doesn't mention they are "stretch" bolts and should replaced like it does for the head bolts. Looking on Turners website it says they are stretch bolts and should be replaced. Anyone know for sure which is correct? Thanks Mike

Bowie69 I'll give it a go cleaning with petrol then. Rotors really are very scored where the lobes run against each other. There has been bits of metal or grit going through it, also evidenced by the crank and bearing scoring. That's why I want to make sure the oil cooler is thoroughly cleaned out. ThreePointFive thanks the pointer to Turners, will give them a look. Mike

Well this hasn't progressed much, the local machine shop, small father and two sons business, where my block and crank are have been hit by Covid. Fortunately they are now recovering and expect to be back on the job next week. While waiting I have dismantled the front cover to check the oil pump. The rotors are scored and require replacing. Officially the front cover is replaced complete, quite expensive! I have found some places selling just rotors but they all come in a blue box! Don't fancy those for a critical component. Anyone know of any reputable source for these? Also I want to flush out the oil cooler, but there is no way the pipes are coming off the cooler. So it will have to be flushed through the pipes. Wondering what's best to use for flushing. Thinking of putting Jizer or similar in though the pipes and sloshing about then flushing out with water. Repeat several times then put somewhere warm to dry out thoroughly. If anyone has a better method please let me know. Thanks Mike

Engine now completely dismantled. Crank definitely needs a regrind, main shells were all completely down to the copper and scoring on the crank journals. I'm amazed it wasn't noisier! Block and crank now with local machine shop for assessment. With his initial quick look he was unsure if bores would hone enough to remove scratches and still be in standard size spec or if it needs re-bore. He will check it properly and let me know next week. Just need to clean up all the remaining parts now then do the valves etc while waiting for machining. Mike

Got back on this today, The engine is out! What a fight though, all the bell housing bolts were stuck tight had to get heat on them and buy a 9/16 single hex socket. When the came out they had some greenish looking loctite type substance on them. This seems to be a recurring theme on this car, so far the PO or whoever did work for him seems to have slathered bolts in whatever the the green stuff is and/or whacked everything up an impact gun. Then came to getting the RH head off, this fought back in similar way to the left hand head when I first had that off a couple of months back. Couldn't shift them on the engine stand. Had to put the engine on the floor with a piece of box section bolted to the engine mount with a mate sat on it while I used a 4' breaker on the bolts and then could only just shift them! Strange thing is the instant they "cracked" could be wound out with fingers. Anyway engine back on stand and quickly popped the pistons for a look. Oil rings are all firmly stuck flush with the piston face so they weren't doing much sealing, maybe the cause of excessive HC on MOT test? Pistons otherwise look OK. Tried a top compression ring in one of the bores and the ring gap was 0.68mm against spec of 0.5mm max, presume this indicates worn rings? Pistons are "B grade" which RAVE lists as service replacement. So looks like someone has been in before unless "B grade" were ever fitted as factory installation? Bores look reasonable, still have faint honing marks in places. A couple have very light vertical scratches (not the one with low compression) which may hone out. A couple have slight marks like you get when an engine has stood for a while and rings have been freed off after sticking to bore. Again may hone out. Big end shells worn out down to copper. Very light scoring on crank journals that may polish out. Not got the mains off and the crank out yet. Outside of engine is filthy, so next step is to get everything cleaned off and get the crank out followed by proper measuring of everything. Sure I'll be back with more questions after that Mike

When I lower the the engine as recommended by Escape to gain access to the bell housing bolts. How far can I lower it without straining anything. This is the first P38 I've owned so am not familiar with it, I don't want to break anything! Thanks again Mike

JohnnoK, good idea, I will make something similar for when it goes back in. Escape, I will try that when I get back on it. Drizzly weather today and I am otherwise occupied for the next couple of days, so will probably be wednesday before I get another go. Thanks Mike

Torque converter bolts are now out, they were tight! Had to take the sump off for better access and get an impact gun on them. Started on the housing bolts and got the bottom ones OK but struggling with the middle and upper ones due to the limited access. Decided to take heads and exhaust manifolds off in the car to give better access. Left hand head taken off complete with exhaust manifold no problem. Struggling with right hand head as the manifold flanges seem to be overlapping some of recesses where the head bolts seat, including the one with poor access under the ABS block. This is stopping the socket going on the bolt square and is going to round off if I apply any force. I don't want to end up like this again! Especially with the even more limited access at this side. So decided to take the manifold of the head first to give clear access to the head bolts. Then found all the heat shield bolts have corroded to the point where so can't get the shields off! Been pratting around with them for half the afternoon with no progress. Might take air chisel to them tomorrow, but don't really want to destroy them they are expensive for what they are. This engine seems to be fighting back at every turn! Maybe this is why I didn't have a Land Rover for a few years 😉. Back on it tomorrow weather permitting (RR doesn't fit in garage so engine has to come out on the drive). If anyone has suggestions for a cunning way to remove the heat shields it would be very helpful. Thanks Mike

Thanks for the pictures Bowie69, they confirm I'm on the correct bolts. When I said 10mm I was referring to the thread, that's what Microcat says they are, the head is 13mm. Will be having another go this afternoon. I'm going to get hold of a 3/8 drive single hex socket and have a go with that. Thanks Mike

Well 2 months on and garage floor is sorted and nicely painted so back on with with engine rebuild. Started to take the engine (4.6 GEMS) out today and all going well until it came to removing the torque converter bolts. Access plate at bottom of housing removed for access to bolts but can't get a 1/2" drive ratchet in wherever I position the bolt due to ratchet fouling on sump. My offset ring spanner does not have enough offset to clear the crank sensor toothed ring. I can get a 1/4 drive ratchet on but can't get enough leverage to undo. Surprised they are so tight as they are only 10mm bolts, maybe loctited? I presume access is better with the sump removed? so I will try that tomorrow. Also does the starter motor bolt through to the housing or is it just into the engine? Thanks Mike

Hi, Just thought I'd report back on floor painting. I left the floor for about 6 weeks until it was consistently below 8% and also passing the "plastic sheet test" mentioned my Gazzar. In the end I didn't use the Leyland floor paint, I used this 2 pack epoxy paint from Regal Paints https://regalpaint.co.uk/floor-paint/garage-floor-paint/two-pack-epoxy-floor-paint-top-coat/ I used the sealer undercoat and the top coat. Instructions said hard drying time 48 hours and full cure 7 days. I left it for 10 days. I've been moving everything back into the garage over the last few days. The paint has stood up well to having heavy a metal bench moved over it with the inevitable sliding on the floor for the last few inches into position. Also large trolley jack, engine crane, tool chest etc. rolled across the floor. The paint has stood up extremely well, with only very light scuffing but no real damage where the bench was slid into place. Early days yet but very happy with it so far. Mike

Hi, thanks for the replies. Yes it is a 43mm diameter socket which I thought was 16A. If it's normal to have one on a 20A breaker I'm happy with that. I was just a bit confused with the two current ratings on the socket lid one 16A and one 20A. Regards Mike

Hi, Not Land Rover related except that it's where I work on my Range Rover, but thought I would ask here as there is probably someone knowledgeable on here. Anyone know what the current rating of a blue commando socket is? I ask because I've just noticed that both the sockets in my garage run of a 20A RCBO in the consumer unit. I always thought that they were rated at 16A but the markings on the socket are ambiguous (at least to me), see picture. If 16A are they adequately protected by 20A RCBO commando plugs have no fuse like 13A plugs do? Sockets have been in garage for many years, but consumer unit was replaced by electrician a few years back. Regards Mike

Right looks like I will probably go with the cam Elbekko suggested with standard lifters. Yes L19MUD it would have been much easier 😉. At the time it wasn't very convenient to take the engine out so I was going for a quick fix, which almost but not quite worked. Now I've got the opportunity to remove the engine in some ways I'm quite pleased it didn't work so now I can do a proper job! Unfortunately it's on hold for a few weeks as my garage floor is being screeded tomorrow so I'll have to give that time to cure before running an engine crane etc. over it. Mike