JB750

I spent many a long day/night trying to get to the bottom of my Disco 1 overheating issue, and after various components, head skims, gaskets etc. I found a pinhole in the core plug at the back of the block (the one buried by the bulkhead! > ) I whipped the engine out - over a whole day! - and replaced all the core plugs for the hell of it, I figured if one was going then the rest would probably be not far behind. That was around 1600 miles ago, and 'touch wood' she's been solid as a rock temperature-wise since. Hope that is of some help

Thanks for the replies guys I'll try the clean-up, extra earths etc. and if that fails then I'll go with a new battery. The last thing then will only be the starter motor I guess. Fingers crossed it's an earth, but knowing the way my luck runs, I doubt it.......

Cheers Peter, I'll try that in a while, although it started fine the last two times I tried

Ross, I had it on charge for the best part of 24hrs while I was putting the engine back in after sorting the coolant leak. But I guess it may have a cell on the way out which means it wouldn't hold charge properly? I did think battery because she seems to start on the first turn with a jump-start. Peter, I had to remove the earths for the engine and engine-bell housing when I removed the engine, so I think they should be OK, but i will take them off and try anyhow.

Well after spending what seems half of my life sorting out the overheating problem, I think it's sorted! (hope I'm not tempting fate ) The trouble is now, I have had an intermittent issue with starting. Sometimes she will start fine, especially when warm, but other times it will only just turn over as if the battery is flat. The battery is probably around 2 years old, but has not done many starts in that time as i have been chasing different faults on-and-off for most of that time! We went into town today (around 10 miles) and she was fine, started OK when we stopped for fuel, went into the store for some odds and sods and she started fine. Got almost home, nipped into the paper shop for no more than 30 seconds, came out and no start! Luckily someone gave us a jump start. She starts straight away when jumped so I am guessing it is only a battery issue and not earths etc.? Would the battery fail if not being used that often? When it fails to start it turns extremely slowly then after a few seconds all I get is the starter relay 'click-click-click-click' like a bl**dy woodpecker! Thanks guys

OK thanks Iain. I did think of peening over the edges slightly to help retain it. Not sure how long the washer has been 'free', but you can see marks where it has been bashed against the cover. I'll give it a go and start looking for a replacement electric version, maybe second-hand will be OK as I need to spend as little as possible now seeing as how I've spent plenty on everything else! As long as I can keep the servo assistance that is the main thing.

I thought exactly that! I wondered if that was why it had come out. Iain, I guess I would like to change it for an electric pump as you suggest, not sure how much they will be here in the UK or what spec I will need (apart from 12V) but as the pump so far seems to be working OK, would I be alright to put it back without the retaining ring temporarily as it was just floating around in their anyhow and was probably the ticking sound I got sometimes when running? I could try opening it up slightly with heat and re-fitting it which may give it some tension back but not sure. (BTW, I saw your reply about the electric pump from OZ-drag, but have no idea what I am looking for regards spec hence the question above) I did a quick eBay search but the ones I saw were almost as much, if not more expensive than the Wabco pump! JB

After finally (I hope!) sorting out my overheating/loss of coolant issue, oil change, new coolant etc. I got the engine back in and started last night. Unfortunately I now have an oil leak from the dreaded Wabco vacuum pump I found the info on re-sealing the front cover and removed the rivets and front cover to find the insides as shown. There was a washer-type piece just loose in the casing! At first I assumed it was from the part without the star clip/washer (the black valve on the left) and that it had somehow come adrift. But the valve that is in there does not seem to be able to come out of the recess so I am assuming the very small lip on the casing stops it coming out. It fits perfectly in the other recess on top of the star clip but will not stay so i am assuming it does not belong there. My last theory is that it is used to seat the clip in place evenly (I removed the clip and then reseated it and used the washer to tap it in evenly). I wondered if it is possible that it was a 'Friday' build and some wally had left it in the pump? Clutching at straws i guess but I can't think where it goes or how it has come adrift. Any help/advice is most welcome. BTW, the brakes were fine last time I had the truck on the road. JB

Finally got everything back together, engine started up pretty quickly and ran sweet. I let her run until the temp stabilised and it seemed steady and no signs of any water leaks so far. I will check her again in the morning and then try a short run to get the thermostat fully open so I can check the radiator and top hose for leaks. I did find out while searching the forum that there is a core plug behind the water pump and mounting which I didn't know about! I am not sure whether to try and replace it in-situ as I have replaced all the other core plugs as a matter of course while I had the engine out. Only thing is..........damn vacuum pump is leaking oil!! I'm going to do the repair that has been posted on the forum as the brakes seem fine, but I'm sure it is only a matter of time before the pump gives up the ghost. I am now after information on fitting an electric one (any recommended types?) and blanking off the block where the mechanical one fits. Any info would be gratefully received. Cheers

Cheers guys. New bolts are on order now, seems a small price to pay for peace of mind. After all, I am spending a fair bit of cash and a whole lash of time on it this time so I might as well go for it! I just hope after all this that the damn thing runs for more than a couple of hundred miles without issue!

OK thanks. All I've got to do now is find somewhere to buy them without paying an arm and a leg.....

I've been advised by someone else that they will be fine to re-use? Not sure what to do now

Anyone know the part number for the 8 flywheel bolts for the 300TDi? I've searched around on the internet but not having much luck. Apparently they are supposed to be replaced once removed and tightened to 146Nm Cheers.

One option I was given was the replacement of the ECU or throttle sender, but as both are ridiculously expensive and there is no guarantee they are 100% OK unless you buy new, I decided on the latter route. It was a good while ago, but if there is any info you need that I can help with just let me know. I can always take a look at ours to see what runs where. Hope you get it sorted, and keep us informed

Sorry to be the bearer of bad tidings, but this sounds awfully similar to what happened to ours a couple of years ago. I got the man with the computer in to fault find and it came back with a faulty sensor in the top of the bell housing (used in conjunction with the stupidly expensive injector in #4 pot). I spent 11hrs along with a more knowledgeable chap separating the engine/gearbox because the sensor actually broke off in the casing when trying to remove it. When we eventually got it all back together, started her up and hey presto! No change!!! Following much more 'try this and try that', including another injector pump, another stupidly expensive injector and a few other oddities, I gave up and decided to replace the EDC system. I replaced the injector pump with a non-EDC one, layed another throttle cable from the pedal to the injector pump (making the fly-by-wire throttle inactive). I removed the ECU and EDC sensors on the intake side. After sorting out all this, the truck started the easiest it had since we got it, almost zero smoke from the exhaust (pretty impressive for a Disco 1! ). From that time on she had always ran sweet as a nut. I say 'had' because I am now mid-engine removal/refit to sort out a knackered core plug at the rear of the block. Fingers crossed that your issue isn't quite so dramatic, but it certainly sounds ominous. JB

Yes Iain, you're right, did the lapping in last night. I saw a great video online from the US where the guy was doing the same and had a quick way of testing for a seal in the valves. Simply fill the valve cavity with a solution of water and washing-up liquid (same idea as for finding a leak in a tyre) and then use an airline to blow air in through the port. I did the lapping the normal way and checked for the continuous grey line all around the valves and seats (old skool way ) then tried the airline trick. Found 3 of the four inlets blew a lovely stream of bubbles, so I re-lapped those valves and now all are sealed. I'm not sure if it is going to show leaks the way that your method does, but I think it will be pretty close. With regards to the oil leaks, I replaced the lift pump recently and used gasket and compound to seal it, but I also suspected the vacuum pump so removed that and ordered a new gasket for it. By welsh plugs, I noticed 2 plugs that look like core plugs on the front of the pump, I guess this is what you mean? If so, I don't think they are leaking as the body of the pump seems reasonably clean. You also mention that the your engine is quieter when you replaced the pump, I have noticed a sound from the engine area (a little like a mechanical ticking/whirring noise) which you can hear from inside the cockpit more as there are less 'diesel noises' than when listening under the hood. I wondered if that may possibly be the culprit? As as a matter of 'just in case', do you have any more information on fitting an electric pump as this may be a future project? Thanks again for all your good info mate JB

Managed to get the head skimmed today. The guy said he took around 3 thou off (approx 0.076mm). Not too bad apparently. So at least I now Know it's flat again Just got to wait for my gaskets etc. to come so I can get the damn thing back together and hopefully on the road!! At least it's given me an excuse to get everything cleaned up in the engine bay, there was a fair bit of oil flying around over time from odd little weeps and it's amazing how much it soon covers the whole bay!

I think I've confused the issue I know I am getting the head skimmed, but what I was trying to say is that the allowance for the piston proud measurements from the block to decide which thickness head gasket to use states 0.71mm to 0.80mm. My concern was that when you skim the head, you actually bring the face of the valve nearer to the piston by virtue of the fact that the distance between the valve face and the head face is reduced slightly. But because I have 0.04mm piston proud allowance before I would need to go to the no-hole gasket, then I technically can remove that much from the head face before it would be an issue. The limits for head gasket thickness still apply whether I have an increase piston proud value or a reduced head face to valve face value. The end result is the same, the valve face needs to be a certain amount away from the piston face. I guess I am understanding the clearance thing slightly wrong, the reason for the head gasket selection is more for the pistons clearing the head face rather than the pistons? Hope I haven't confused the issue even more

OK Iain, thanks for that. I know the valves will be closed before long before and after TDC, but I guess I'm just a naturally overthinking worrier When I looked at the range of measurement for piston stand proud for a 3-hole gasket is 0.71mm to 0.80mm. So assuming my estimation of the stand proud value of 0.76mm is correct, I still have 0.04mm to play with anyhow, so even skimming 0.02mm off the head should still leave me in the clear. Just finishing off cleaning down everything ready for re-assembly and waiting to get it skimmed now so I can start putting it all back together! Remind me again why we own Land Rovers?

Boydie, not sure if there is a link issue but the one you gave takes me back here

Thanks for all the good info guys I have the Rave workshop and maintenance manuals so have all the good info you have about gasket thickness etc. With regards the skimming affecting the thickness of gasket, I thought that as material is removed, effectively the valve faces will be a little closer to the pistons which is why I wondered how much can be removed before needing a thicker gasket, if that makes sense? I have just ordered a 24" straight edge so in future I can be a little more accurate than my present methods! I also have a DTI so can measure the piston rise for gasket thickness. Doing a rough check with feeler gauges the other day pointed to the current 3-hole gasket being correct. Thanks again for the input, I will tray and get the skimming done this week. JB

Thanks again Iain. Looks like a skim is in order then? I will take your advice on the 3 waterway areas, I have seen a video on youtube with one that has corroded very badly so junked the head! For all the hassle I've had in the past, I am not taking any risks again, if the head need skimming it needs skimming. I am on a 3-hole gasket at the moment, do you think I will need to stay with that thicknes (1.5mm) or go for the no-hole one (1.6mm) after the skim? Thanks again for your input JB

I have just lifted the 300TDi engine out of the Disco, and it seems there are 2 of the 8 bolts that fix the engine mount plates to the block. Does anyone know what size I need or the part number please? Thanks, JB

I have cleaned the head up and checked for warping as best I can with what I have: I have a thick steel rule which I have checked against the engineers block I have and am confident it is true. I then used the rule on the head to check for bowing, and as far as I can make out, there is at most 0.02mm of gap in the centre of the head. I took some pictures shown here. What does the collective think? The white bits around some of the valves is just paper I used to wipe off the head after cleaning. What do you reckon guys?

Finally got the donk out last night and fitted to the engine stand. Had a pig of a job getting the front low enough to get the top bolts out of the bell housing because the damn steering box is in the way! Anyhow, took out the core plugs and I think it is safe to say that the rear one is foobarred! Had a heck of a job getting it out too, hence the rather larger than normal hole to lever it out. The others came out fairly easy. I'm 99% sure that this is where my coolant loss problem was. Under pressure it won't take much more than a pinhole to start losing coolant rapidly and there is a real string-of-pearls along the bottom edge of it!. While I've got the engine out I will try and find out where all the crud and oil is coming from, it's not leaving puddles under the truck but there is a pretty good coating on the right side of the block and all the running gear underneath. I've checked the rear seal and it seems OK, I think it might be from one of the ancillaries bolted to the right side of the block. Now need to get my order in for new head gasket, bolts, thermostat housing gasket, locating dowels are pooped too (inlet/exhaust gasket) looks fine. Think I'll treat myself to anew torque wrench too, mine is a little long in the tooth and probably well out by now. I've got an angle torque gauge so should be all set once I get a new wrench. Watch this space for the next episode........