Cret

I've thought that the head gasket must have a slight leak for ages on my disco as it seemed to be using coolant and I wasn't finding leaks at all (after replacing one damaged pipe at least), but since it seemed minor and I use the disco infrequently (it's not my daily driver now but my 'utility' truck) I hadn't worried too much about this, just made sure it didn't get hot, and topped up the coolant as required. Recently it's had a couple of runs where it's been able to properly get up to temperature and do a few dozen miles, and I noticed something horrible some time later. The radiator has inflated! Now I replaced the expansion tank cap some time ago because I wondered if it was faulty, and it looks like ironically the new one has broken. The yellow plastic bit in the middle seems to be crooked, so I'm guessing it's jammed somehow. So I'm guessing that pressure in the coolant system has been able to build up more & more until it's turned the rad into a balloon! Very nasty. I'm assuming at this stage that there's no way in the world that the head gasket could still be in one piece with this sort of thing happening. What I'm concerned about is the possibility of a cracked head? How common is that, and is it just overheating that causes that? I've been careful to keep an eye on the temp gauge and it's always been kept at normal levels. It's crept above a couple of times but only just, then I've given it a rest before topping up coolant. Is there any way to know if the head is ok before removing/dissassembling to do the head gasket? I know about the dowels and stuff when doing the gasket, but where can I buy the metal ones? Many thanks! Jim

Yep - my one split, although it's still never been brilliant even after replacing it. Think that's just general wear & tear elsewhere though.

OK - updates: Today I replaced the thermostat (what a pain in the hoop to undo the clamps as they're spring ones, not jubilee type!), the top rad hose, the header tank cap, and the propshaft donut. Not been able to do a proper test jet as there's been alsorts of stuff going on today. Hopefully can get out again shortly though. Found a few things that rather surprised me. First was in the EGR replacement pipe from IC to manifold. It had emulsion in it. Nice grey layer of sludge, which was also present in the hose coming to it from the outlet of the intercooler: Yuck! Now this made me think "Yeah, definitely got a head gasket problem then", but then I thought about it and I'm a bit puzzled how it could have emulsion here. Basically the turbo sucks in fresh air, it gets compressed, goes through the intercooler, then goes through these pipes before going in the engine. So how can this muck be present here when there shouldn't be any water/moisture, and no link to the coolant system?!!! The oil filler cap had no emulsion and dipstick was ok too. Inside the entrance of the manifold it was just like black tarry oil coating the inside surfaces, like last time it was apart. The next thing was that there was a pressure leak in the EGR replacement pipe. It has a welded on boss on it, and I found this was leaking and fixed it. Is it possible that moisture has been drawn in through this somehow (condensation after the car is used?), mixes with oily fumes or something, hence then giving some of the clouds I've intermittently had out of the exhaust recently when a bit of the sludge gets burnt??? :?: Can't really see how else there'd be sufficient moisture there to mingle with whatever oil type stuff is mixing and emulsifying. So I'm still not sure if there is a head gasket issue or not. I haven't yet got the full amount of coolant in yet, and the heater is still blowing cold so I need to bleed the system I think to sort that, then I can monitor coolant levels over the next week or something. Next issue: Swapped out the propshaft donut and that was easy enough. I think the bearing in the middle of the donut needs replacing and a new one came with it but I ran out of time and had to get the car back together. What's the easiest means of changing the bearing? Do I need a slide hammer or something to remove the old one? Lastly - one of the UJs is really shafted and I'm worried about using the car so I need to replace it as quickly as I possibly can. This is obviously where the mystery squeak has appeared from, as others suggested! Are all the UJs the same part number along the front & rear propshafts? The broken one is the front one of the pair just in front of the transfer box: If anyone has the part number for this UJ on TD5 Disco I'd be grateful, but I'm sure I can find it without too much hassle online or on Rave or something. That's all for now folks!

Ooh - good spot mate, that's cheaper than the one I was about to buy earlier. Dunno why I didn't spot the same one, cheers anyway. Well aside from coolant issues the car could do with a respray as the lacquer is all coming off the bonnet, locks need looking at, as does one rear window, etc etc.

Thanks chief - I will definitely get the donut ordered in the morning then! In terms of the bush you mention - I take it that's something that has to be ordered separately? Any idea on the part number? No worries if not. Assume it will be visibly worn if it needs replacing but will have a look. Noticed of course with UJs that they have grease nipple I think so perhaps one has dried out and has caused it to squeak. Either way, if I have to remove the shaft to fit the donut I will check them out fully at that point, but will have a quick look in the meantime to see if I can spy anything obvious. Thanks for the info anyway - am hopeful this is where the vibration must be coming from given symptoms matching other people's and mine is worse than yours was etc. Cheers for the link too - saw a similar how to earlier on but not the same one. Always good to see a couple of takes on a job. So currently awaiting delivery of: New rad top hose (to see if it solves the coolant loss through bleed screw) New thermostat (in case the coolant issues relate to that somehow - doubt it but you never know) New intercooler hoses (silicone ones) New header tank cap (in case that is related to the coolant issues somehow) And a donut and possible UJs to order. I won't making a list for the rest of the car!!! Especially since I've started getting really naughty thoughts on a variable vane turbo to go with the current chip/boost box/huge intercooler. Would go REALLY nicely with those other bits I have to say....

I got a sound clip earlier of the squeak with my phone. Pretty hard to hear I'm afraid but you can make it out at around 9-11 seconds into the clip. Only does it under load and usually the likes of pulling away from lights etc. http://dl.dropbox.co...-14%2017_31.wav Sorry it's not the best quality audio!

Thanks for the suggestions chaps. Any easy way to be sure if they're shot - eg is it the case if I can wiggle them by hand then they're gone or something? And is it likely to be just one that needs doing or....? Presume this is the right bit(s) that I'd need: http://www.ebay.co.uk/itm/LANDROVER-TD5-PROPSHAFT-U-J-/370551665969?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item564699b531#ht_500wt_1054 Any hassle to replace them or easy/straightforward? Anyway, after reading about this dodgy donut issue I popped out to have a scan under the car to check out the condition. It's not good and is full of cracks but isn't actually splitting apart or anything yet. Needs replacing from the look of it (see for yourself below), but what sort of state are they usually in to start causing vibrations? It's started happening fairly suddenly over the last few days, and only does the vibrate thing some of the time, but it does seem to kick in around 50mph mostly, and often has a deep drone sound with it, which seems to match what other people have said with theirs. The squeak thing seems to have begun at the same time, but could just be coincidence I guess., Here's what we're looking at on mine - looks ropey but no idea what these are like when others have had this problem: Cheers

I'd love to know this too as mine has just started doing it as well. Seems to be just when engine is under load, and not all the time then either. It's slightly ominous but sounds the same as you chaps. On top of that there's a quietish 'twittering' sort of noise sometimes when engine is under load too. I keep thinking it's a turbo fault but not sure. It's certainly not a normal noise for a turbo to be making if it is coming from there!

Hi Mike I've been meaning to update this thread for ages and have just been chocka busy and more than a bit sidetracked so apologies to anyone with an interest. Yes I had the kit all up an running. The disco pulled slightly better with the water being injected but only under certain circumstances from the little testing I got to do. I think the jet was actually too large for my needs at 0.5mm and I didn't have smaller ones to try. Amusingly, there were a couple of occasions driving uphill under heavy load where there was visible mist in the rear view mirror! Unfortunately having since that point been focusing on the subaru and getting the rebuilt engine back into that I've reluctantly had to sell the kit to raise a bit of cash. When funds permit I'd like to replace it with another kit and continue this as there was certainly some promise, but unfortunately I've been forced to spend the sale proceed on things like water pumps/fuel pumps/helicoil kits etc for the legacy. If anything I want a water kit for that now it's back on the road. I have a new ecu to begin mapping shortly and it comes with a charge temp sensor that can be logged so the water would be an excellent addition but maybe later when I'm not so skint. Worth a try if you're considering it anyway. I definitely had some minor improvements, and that was without even any meddling with flow rates, jet size, activation pressure level etc so there are certainly improvements to be had. Just sorry I've not been able to expand on this further. Jim

My friends tell me I look like him. I even have a scar in the same place. Oddly enough, "Mann" is where I live (although some of my family are actually from Belgium). Anyway - Last night I fabricated a bracket to bolt the water tank into the engine bay. I already had a nice stainless water tank that my mate made for me ages ago so I welded the bracket on. It's going to fit just in front of the firewall on the left hand side as there is lots of space there and a bracket sticking out of the firewall with nothing on it. Perfect! Now the pump is meant to be at the same level or below the tank to get a good feed. I've also welded a bracket for the pump to bolt onto as you can see in the pic. I think it should be ok as it's a tiny bit below the tank, but the good thing is that I have got a washer motor (attached in the pic) which can be used as a priming pump for the main ERL race pump. Apparently, doing this really increases the flow through the pump as well, so I might need to get a smaller injector as the one I have got is 0.5mm and can flow 210cc/min before even having a primer. I'm waiting for parts from Aquamist which they're still making at the moment so I can't use it yet, but I can get it all bolted in and wired up ready. I think I will set it so it only comes on at full boost, otherwise with the way a diesel uses its turbo the tank will be empty in no time!!!

Not thought about putting a carpc in the disco yet but I've got one of these combos for my legacy so I can tweak maps in FCedit etc and get power curves with Dataloglab without needing me laptop. On top of that the hard drive stores tons of music and I can add in numerous satnav apps. They're a lot of mucking about to get working just how you want but dead handy things to have!

I like the idea of upgrading to the next system up where you can map the water flow to a parameter from the engine to have a varying amount. Can't afford to do that though, and I've yet to see if it works well yet. Think I've resolved a minor issue tonight anyway. The remote mount kit I need for the pressure switch alters the switch from using a thread to a 4mm hose barb tail connector. That's fine as I have a big coil of 4mm nylon hose, but it needs to join into flexible pipe that's around 6mm (that feeds the boost gauge), and it looks like aquamist don't do an adaptor. So I made one on the lathe! Now I've had my mini-lathe & mill for a couple of years but rarely get the excuse to make stuff on them so this was a treat. All pretty randomly made, and amateurish at best, but I've made a hose adaptor to join the 4mm hose to the 6mm hose quite firmly. Here's a photo of this part next to a teaspoon for scale: And the size of it against a steel rule (scuse the blurry phone pics!): I was convinced it was/is going to snap, being made of ally and being so small (about 2.5mm wide at its narrow point) & hollow but we'll see in due course. I hope not! All good practise and it's one little installation problem out of the way anyway, so I'm quite pleased with my handywork.

I'm staying out of this one about the turbo flow!

Just read that autospeed intercooling article and it was a nice read. I've not really considered previously that the diesel has different requirements in the way it describes but it all is totally understandable. If anything, I would expect that this increased desire for efficient cooling on the charge should mean that the water inection may given better results than I was originally expecting, especially as the car is now chipped & under increased pressure & therefore increased heat over standard. Having read that, I like the idea of fans. I actually found today that I still have the pump, solenoid, and injector from my original cheap nasty water injection kit from several years ago, and these could be put to advantage by being used as a very fine misting spray on the front of the intercooler, like subaru use on certain STi Imprezas. Was interesting to see mention of the very same chargecooler that I used to have on my Legacy too! The Liberty RS is the same car as the Legacy RS which I have, just the Australians called it Liberty in stead of Legacy because of some ww2 issue, and it is a lower tune, but the chargecooling system is what was originally on my car. I have upgraded this to a front mount which works better and does not have the problems of pumps failing etc. The front mount also causes some entertaining noises on closed throttle (petrol engines only obviously) where compressed air goes back over the compressor wheel, although it should be removed by a recirc dump valve really for turbo health. I like the idea of the datalogger too. I do actually have a datalogger for the subaru's apexi powerFC ecu that I run & map myself. I doubt I could use it on the disco though. It's an FC Datalogit unit that I have: http://www.fc-datalogit.co.nz/ The plan of using MAF data is an interesting one indeed.

Thanks for this Mike That removes a lot of guesswork from it. I've looked at the bit you described and it looks perfect, BUT.... Unfortunately it turns out the probe that came with the gauge I gotis pretty long, and if I fit it there it would basically be long enough to come out of the bottom of the manifold as well I think! Real bugger! I suppose it might be doable to drill and tap the hole at an angle. The other possibility that I've wondered about is bending the probe as I've read a thread (may have been on here - can't recall) where someone did this without any real issue. Might be possible to buy a shorter probe presumably but if I'm going to have to resort to doing that it might make sense to try the bending option first since there'll be nothing to loose really!

Right! Injector side of things is sorted out now so I just need to get the bits to plumb in the pressure switch, then mount the kit. The tricky stuff is (I think) done now!

Cheers - I've been planning on moving the boost takeoff to the inlet manifold side for that reason as that's where you get the usuable boost figures from. It's on the turbo side at the moment for ease of fitment (the boost gauge takeoff I mean), but just poking my head out of the garage for a moment it doesn't look like there's a suitable takeoff point on the manifold area so I suppose that's more tapping/welding required to add a fitting.

Thanks Cieran I've just had a look at the manifold and it looks like it ought to be quite straightforward to remove with the turbo out of the way, but I know sometimes that in itself can be a chore. The manifold looks very thin, so it could get interesting in terms of the probe itself as it's rather long! This could get interesting....

Thanks for the reply again David Going to have a read through those articles and see what's what, but at a glance they look quite interesting. I've made a little progress last night anyway. I now have two bosses welded onto my egr replacement pipe, one for the injector, and one for the pressure switch. Blurry photo attached. They need to be drilled & tapped next, and they're 'funny' size threads (ie not ones in my cheap & nasty tap & die set). Luckily, aquamist supply a tap for the injector with their kit and I still have that, for some odd reason they don't appear to provide one for the pressure switch though. No idea why. The one I need is 0.9mm thread but am unsure about the width/size required as it measure a bit different to normal 'M' bolt sizes. I might hand it over to a friend of a friend who is an engineer, and see if he can do it for me. It'll be a much better job than me doing it even if I get the right tap for the pressure switch. *edit* Having cut & welded on the two bosses - I've just found out that Aquamist supply a remote mounting kit for the pressure switch with an adaptor that screws on to enable use of a barb tail fitting and small hose supply for the pressure feed. This negates the requirement of having this drilled & tapped so I can sort of get on with the installation if I do the other thread myself. All for a measly £6 too! Think I'll be ordering one of those today then.....

Thanks for your post David - yes that is helpful. I do have a reasonable bit of faith in my own abilities as I've been car fettling for something like 18 years now. Way less than many of course, but I've learned a lot of bad ideas and a lot of useful stuff over that time. I'm certainly not beyond making mistakes though, so I'm a fan of asking what I don't know before trying things that I don't have direct experience of. For instance where a job might be quite time consuming to find out myself (due to wife, kid, house to do up, car to do up and boat to do up etc), or has high potential for causing damage. Interesting comment about the swarf in terms of it being blown through (not something I'd considered) but it's a little bit hit & miss for my liking, and as you say it becomes irrelevant if I remove the manifold anyway. The theory about the unknown factor of the inside of the manifold is perfectly sensible and I suppose it would thus be silly to guess as a result. I don't fancy having a manifold riddled with 'test' holes either! So that brings me to another question then - is it a pain in the backside to remove the exhaust manifold on these engines or relatively easy? I've found some cars in the past to be horrific in terms of things that have to be removed first to provide sufficient clearance etc, so I'm wary of simply ploughing in without seeing if people know first, but if it comes to that then that's what needs doing. I have a Rave manual somewhere so I'll see if that says & will do some googling etc, and will simply go out and have a bit of a stare at it of course and see how it looks. Appreciate the reply anyway, thanks.

Thanks for the links - they're interesting reading, and there's a bit of useful info in general terms of fitting. The EGR takeoff point on the tdi looks perfect, but unfortunately on the TD5 that's at one end of the manifold instead of in the middle like they appear to be. I doubt it's a suitable spot for accurate readings therefore (unfortunately). So am still not sure about any of my questions I suppose, ie: 1) Best spot? 2) Do i need to remove the manifold (because of swarf)? 3) Is the manifold a complete bugger to drill?

Quite correct Gaza. Think I made a comment about this earlier on as the washer tank is the typical source of choice for the water tank, both because of convenience of already being there, and because washer fluid is (ish) 45% methanol. Handy indeed! Little update - my mate is 'booked' to come over in the next few days to weld bits on my EGR replacement pipe as injector bosses etc. I can weld - sort of - but this needs to be neat. Once that's done & they're drilled & tapped I can get it all in. Other than that, I got the dastek working correctly today. Found the boost signal wire was a bit knackered so I sorted it out and bloody hell! The disco feels like it's transformed!! Lovely throttle response, goes a shedload better when you put your foot down, and not a whiff of smoke that I can see so far. Love it. This should hopefully give the water kit a real chance to shine since it's a sort of intercooler equivalent and an intercooler is meant to give most benefit when combined with an increased tune. Even if non of this makes much difference I'm dead chuffed with the performance and 'nice factor' the dastek has provided.

I know I've mentioned this in my other thread but am guessing most people won't see this as it's generally unrelated to the thread title. I've just bought an EGT gauge this week. Was thinking it would be a good while before I could spare the money for one but I got this all new for a snip at £25 so it would have been rude not to. Would like to know from people who already have an EGT gauge fitted where exactly they have the probe fitted, and how much of a ballache it was to fit. I've already had a couple of comments on this suggesting a certain spot on the manifold, but would love to know from other people who have one fitted how they've done it, even with a pictures if people are feeling extra helpful! Does the manifold need to be removed to drill it? The reason I ask is because of the concern that swarf will fall in as a matter of course and end up damaging the turbo next time I fire up the engine. Perhaps it's possible to drill it in situ then get any bits out with a magnet or something?! Also, I'm not sure what exact kind of metal the exhaust manifold is but I'm assuming it's a very hard cast metal & potentially a mass destroyer of drill bits/taps etc? I've got some cobalt bits which are very good but I'd rather not chew them up if I can avoid it. Appreciate any useful info on the installation of one of these anyway, as it would be a nice think to have fitted so I can keep an eye on things after 'tinkering'- thanks in advance for any good tips. Cheers Jim

Cheers Lara Don't worry - go and try it was always the intention and still is, the thread purpose was primarily to get comments from people who have already tried this modification so that I can compare notes, see what findings they've had, and get a rough idea of the sort of setup that might work optimally. I welcome the discussion from people who just want to find out more though of course (as you can probably see from long winded replies I make!). I think I may have found the issue with the dastek I just got as well so hopefully that will give me extra potential for good results from the water. Yes I plan to try methanol as well, although initially I want to see what water achieves without it. Cheers for the comment though - you've basically explained what it was that was going on in my head in terms of resolving the oxygen quantity question etc & why I was struggling a little bit (plus it's been a brain frying week again at work and I was also concentrating on not scalding myself with the hot pie I was busy scoffing).

It's not something I've considered, and I can understand the argument you're making so it's an interesting question. I'm inclined to agree with your logic, but what we all do know is that intercoolers make a huge difference to performance by reducing the temp of the inlet charge. That's the bottom line here so we know that your theory notwithstanding, they do work. I don't think it has a detrimental effect even though on initial impressions it might seem like it. As I understand it actual pressure is not of overall importance in a turbo system. This may sound odd but allow me to elaborate. The overall idea with a turbo is to force in a greater volume of air in. That's the objective and the result. The means of doing this is to pressurise it, but for instance if you run a ginormous turbo (lag/spool issues aside) you get the same volume of air into the engine as with a small turbo straining its nuts off, but at a much lower pressure. It's the actual airflow/cfm that counts, not the pressure per se. This is for instance why on my legacy I can upgrade the turbo and run the same boost pressure before/after but get an increase in airflow & thus can increase the fuelling to match via my mapping. The best analogy I've heard for this is to imagine a hose filling a bucket with water. You can use a small hose with high pressure water and fill it up say in 1 minute, or you can use a larger bore hose with a lower pressure output of water and fill it in the same time (ie a big turbo), so the pressure is not really the issue. So yes, I think you're right that the pressure may reduce as you've said, but this does not matter because the volume of air is still there, and that's what dictates the fuel burn & ability to add more fuel etc. As for the amount of oxygen, the addition of water vapour enhances this, not so much the actual cooling. Or something. I know the water vapour does this, but my head is actually struggling a bit with whether the actual cooling of the air on its own provides more. All things being equal I guess not (I'm not a chemist nor a physician though!), but I can't get a lid on whether this matters because of the constant flow of air coming in. Hope that makes some sense, but even if it doesn't as I say the bottom line is that cooling the inlet charge does of course help as we know, otherwise our cars wouldn't have intercoolers. What do you think?