wood-gee

Thanks, I'm borrowing a torque wrench from work to torque the rocker shaft correctly to do the valve clearances properly tonight and will change gasket//try what you've suggested with the air box as well and see where I am after that.

I didn't, as background on it, I thought I had an overheating problem, and having pursued every other potential cause thought it might be that. Only since did I find that it was a not obvious electrical fault, so a somewhat expensive lesson in fault diagnosing. But back on point, I pulled the head off, found nothing obvious (as one would expect based on it actually being electrical), used a machined flat block and some fine wet and dry to make sure the head was flat then reassembled, so the only bits I took out in the process were injectors and heater plugs. As an aside on that, how do the heater plugs seal in the head?

Crankcase pressure seems fine - there's not much by way of gases coming out when I pull off the filler cap and it isn't blowing oil out. I used an elring head gasket (I think that was the brand), so one of the good ones as far as my internet research showed. I think there's a definite risk that the manifold gaskets aren't sealing correctly given that I've had them tight and loose a number of times as mentioned, I was considering buying a new one and changing it tonight just for completeness. There's no obvious gases on the injectors - I snapped a stud and put one in on a bolt originally after the change, and this didn't seal properly, and the escaping gases were really obvious, but I didn't check which orientation the injector washers were meant to be when I first reassembled it, so the back two could potentially be upside down - not sure if this would have any negative effect?

I changed my head gasket recently, and since I've got everything back together engine has what I can only describe as either a knock or metallic clanking sound. The video below shows a bit of what I mean - you can here on the edge of the normal engine sound a kind of knocky / clanky sound (damn am I a good describerer). Has anyone had something similar happen, or any obvious idea what it could be? https://youtu.be/VOFnNRx--yY The noise is RPM dependant, but not as frequent as each cylinder, so I wondered if it were coming from just one. I have had the manifold gasket loosened off then tightened a few times having first made a mistake on the bolts and then after a few trips test driving it realising I'd used too long bolts on the bottom which bottomed out without clamping. It was down on power, but I've since adjusted valve clearances, fixed a hole in the air filter to turbo pipe and reseated an injector I was unhappy with, and its now very much back on power, feels lovely and smooth to drive, but still makes the knocking sound, any suggestions?

Thanks for the advice everyone on this; in the end I borrowed a fancy temperature sensor from work and it was the electrics - (either regulator or gauge, not gt round to proving which one yet), even though the regulator was chucking out 10V (or maybe 9.9V but thereabouts).

It's a one wire sender. Rather than being an issue with the sender, the resistance saturating may well have been down to how I tested it - it wasn't the most scientific, just heating up a pan of water then letting it cool down and repeating. The lack of detail above 95C is also down to how it did it; I only really concentrated on it between 60-95 as that's where it seems to sit under normal conditions (drove about Friday afternoon with the thermocouple in rad and can confirm this; about town driving temp got from 75-80C, under some load say 85C and after thrashing it got as far as a heady 87/88C). Results are below in case they ever end up useful for anyone - temperature on left in C, resistance on right in ohms. 56,144 58,132 60,123 62,118 64,114 66,102 68,97 70,90 72,85 74,80 76,75 78,70 80,66 82,61 84,58 86,55 88,52 90,50 92,45 94,43 96,40 98,40 99,39 98,40 96,43 94,45 92,49 90,51 88,55 86,57 84,61 82,65 80,70 78,74 76,79 74,84 72,90 70,96 68,103 66,111 64,119 62,127 60,136 60,127 62,118 64,108 66,102 68,94 70,87 74,79 76,74 78,70 80,66 82,61 84,58 86,55 88,51 90,48 92,44 94,41 96,40 98,39 98,40 96,42 94,45 92,48 90,50 88,54 86,58 84,61 82,66 80,70 78,74 76,79 74,84 72,90 70,97 68,104 66,111 64,118 62,127 60,137 100.3,40 94,45 92,48 91,49 89,52 88,53 87,55 85,58 83,64 81,68 80,70 78,75 76,80 73,89 71,95 69,102 67,108 65,116 63,124 61,132 59,142 57,153 55,165 54,170 229,46

I intend to post the numbers as well, but in case I forget, I thought I'd post this here quickly as I'd like to think it'll be useful for others. I've done a rough calibration of an AMR1712 temperature sender (blue plastic, the 200 tdi one from a range rover that works with a series gauge) today against a K type thermocouple, only really focused on 55C up to 98C in 2C steps, and did a few sweeps up and down to allow for hysteresis. Resistance seemed to saturate at 39-40 Ohms above 96C, so the trendline won't be wholly accurate. Graph is as below:

It doesn't have a viscous van, and has ran well over the winter with the needle never really moving much, even without the electric fan on.

Doesn't appear to be losing water, Or at least not at a noticeable enough rate for the short test drives I've done this week, but I must say I'm stumped for other reasons, also changed temp sender tonight, checked connections and voltage regulator output (9.8v but my multimeter isn't the most accurate).

So as an update on this, having pulled the pump and concluding that although a bit worn, it was still serviceable, I went and bought a new rad today. Fitted after work, test drove and its still bl**dy overheating. Rads now getting good and hot but I left it sitting ticking over after my test drive and the rad heat soaked after a few minutes and the needle started rising. Man am I fed up! Going to go a garage tomorrow to try and do one of those tests for your coolant, but the only option now seems to be head gasket.

Something I was tempted to try was to use an accelerometer to calculate force then work that back through your gear ratios to get torque, and with rpm power. You could get an estimation of losses by doing some coast downs. Itd only be approximate but what it lacked in accuracy it'd make up for in gimmeckery

Do modern cars calculate fuel use based on what they meter as they inject it into the engine?

That's a great suggestion from Si, another option for achieving trip function which I read about when a guy made something similar for his motor bike was this: https://www.sparkfun.com/products/12708 It's a real time clock with a little bit of non volatile memory which could be used to store trip data, plus a clock could be a nice extra string to the bow. w.r.t replacing odo with LCD, I know for what I've been doing I'd wondered about replacing the trip clock with a screen, freeing up the space behind it for a motor. The speedo face itself has the bars separating each digits so it could look pretty cool seeing a screen through that.

Thanks for the input qwakers; that would be more in line with the symptoms I've had, and in fairness I think it's the original rad, the lad in the landy shop also said rad when I went to get a water pump gasket today but I thought it worth checking the pump before forking out the cash for a new rad.

Ah. Well that would make sense!

2.2 prop rotations per speedo rev, if you google series speedo ratio it comes up on a lot of forums, but basically a worm gear drives the speedo drive pinions, hence the reduction ratio. I'd argue that you could potentially keep the odo etc, and just drive the needle, although I think you'd need to mount your motor off axis to clear the speedo head, although this would work well with using a gear ratio. The main challenge with that I think would be supporting the needle, a small enough motor to fit and gears, but equally I give you the right to laugh at me when I come back and say that it wasn't possible. Yeah, that's what drew me to servos over stepper motors, steppers still need control, often people mention 'zeroing' them off the end stop first, tbh doing it with PID would be cool, all about dat step response. Disco gauge is a good idea and I'd be very interested to see if you managed it, if it's just driven by pulses I'm sure you could do that easily with an arduino (I have a feeling that's what you said your using?) Out of curiosity, have you tried reading the alternator pulses before to get RPM?

Stupid question here, but why are the bushes tight? If my understanding is correct, we tighten up the shackles and then this clamps the bushes so they also behave in a spring like fashion. I can see the logic that this will eliminate lateral play in the joint, but wouldn't it make more sense for it to be a rolling joint to allow suppleness as the spring extends and the shacks rotate?

Yeah, sorry if what I've said has got a bit muddled over the course of this thread. My eventual plan is to both sense the speed of the landy and drive the speedo using a servo motor. What I've detailed above is only the sensing part of that, my logic being that by having both the original speedo and my sensor running I can make sure it's reliable and doesn't do anything strange or buggy before then removing the original speedo altogether, (plus I seem to take ages to make any progress, so it's also just because I'm being slow). The ratio of prop to speedo is 2.2 I think. I was thinking of using a servo rather than a motor, however servos usually only do around 180 degrees, so either use a sail winch servo, which do more, or gear a normal servo. This means you could still use the speedo drive as input, plus my understanding is that servos don't need feedback, whereas you might need closed loop control if you wanted a motor to be fairly accurate, which seems like work that could be avoided.

As far as I know it is, I tested the old stat that I removed and the new one I put in a pan of boiling water, both of which opened? I put the new one in reasoning the old one might have gone out of calibration. Today I removed the water pump to check it's working. The impeller is attached to the spindle fine (I've read about 300tdi ones coming apart from it occasionally), however the blade edges did look a bit messy, pictures elaborates below: Most of the blade edges looked like this; is that normal? I would reason it wouldn't be enough to cause overheating but doesn't look ideal to my untrained eye. Other than this the fan feels ok, bearings don't feel brand new but could be worse. After pondering it a lot today my current thoughts of the cause for overheating are: 'stat not opening - unlikely having proven to open in sauce pan unless there's other causes I'm unaware of? Semi blocked rad - did seem to flow some water though when hosepipe tested Head gasket blown (suggested by one of the technichians at work)

Sorry I didn't clarify on that, I have the disco radiator fitted. The heater temperature is hot, I've had it on full chat and had to keep the front vent and window open to prevent myself cooking. The fuel gauge has stayed sensible whilst the temp gauge has shown overheating, and the fact that it was going up and down rather than constantly showing hot led me to conclude that the gauge is fairly truthful, whereas I would have expected a constant offset in the instance of a dicky earth or suchlike, plus I had checked the regulator output earlier and it was chucking out a sensible 10V.

As promised, here's the final detail on how I got this working. As mentioned, I put a hall effect sensor inside the speedo head. I did this by making a little aluminium plate which picks up off some of the mounting holes in the speedo head which the sensor bolts to, shown here: I stuck a D-sub connector on the other side to connect to it, seemed a good idea as connector screws on so it shouldn't come undone when pulling on and off the dash (an issue I've had by using header pins on my LCD screen). Also lots of pins spare on it to allow for future improvements! This then attaches to the speedo head as show below: Another view on the position of the sensor relative to the speedo head Made a hole in the back of the speedo case for the connector to stick out of - positioned where the voltage regulator use to be as I swapped it for a solid state one a while ago. The sensor and connector can be seen attached to the case below: Issues I've found from this: D-sub connector is a nice idea, but positioning where I have means it fowls the heater duct, either needs a low profile connector or to be in a different place I originally removed 2 of the 4 screws holding the head together, put one back in. When the speedo is fully tightened up to it's shell without all 4 in the pressure from the tubes used for the warning lights push the two parts of the speedo head apart, prevent the needle from running straight on it's bush, and making it drag noticeably. I addressed this by putting 1 screw back in and shortening the tubes slightly.

I'd really appreciate if someone may be able to offer me some advice. I've got a 200 tdi in a series 3, and up until recently it's always ran very well, with the temperature needle never really moving. A few weeks ago I noticed it would occasionally creep up a little on the temperature gauge but didn't think anything of it. Last week it overheated noticeably according to the gauge, so I popped in a new thermostat, although I then checked the old one which seemed to work fine. A few test runs later and still overheating, what I found was if I stop it cools down fine with the cab heater on, but can't seem to deal with the heat of driving. Today I pulled out the rad, gave it a good flush through, (it seemed to be flowing water ok), checked the hoses, refitted and tried a test run again. Still overheating. What I noticed is that when the gauge indicates it overheating, the very top of the rad is cold, the very bottom is cold and the middle warm. I wondered is whether this is because the oil cooler is doing it's job fine but waters not getting to the rad? If anyone has experienced something similar before or might be able to point me in the direction of a likely cause I'd be most grateful. The main other element I feel I've not checked is the water pump, is there an easy way to do so? Thanks

Thanks guys, this is exactly the kind of thing I was after hearing - what people have found works for them etc (minus the silly comments inferring superiority of 109's, and that's not because I'm jealous you can sleep in them at all!). As far as my expectations go, I know it's never going to be silky smooth, but I'd heard people talking about their parabolic equipped series coming close to coilers, or even exceed them as Pollywog has said (I do recognise that this is a very subjective measure of suspension performance) and I'd say mine's still quite far from that (coilers I have in mind as reference where my parents old 2.5NA 110 and disco 1) On the shocks, it sounds like I could definitely benefit from a change in that case, is there a specific one that's best to go for? There's been Bilsteins and pro comps mentioned, are either better/worse than each other/are there any others to look out for. Tyre pressure wise I've been running about 28psi i think all round, I had begun with 35 or so as I thought it might save me fuel, but then tried letting them down one day and it was a revelation w.r.t ride quality. Is 28psi a sensible pressure to run at? I tend to drive with my spare wheel in the back, for a bit of weight, plus allows a little more view out the windscreen, but I do think it suffers a little by being a light configuration on fairly generic springs, it'd be interesting to try it heavily laden one day and look for an effect on the ride based on what's been said about that. In terms of springs I've got the correct ones for SWB (I forget the number of leaves). One of the rear shackles is a little seized, which I've been avoiding, but the rest seem OK - although surely this would only make the ride feel harsher when the rear axle goes over bumps? Thanks for the pointers anyway, gives me some food for thought!

I've got a SWB series 3 truck cab with paddock parabolics and currently stock shock absorbers. I'd currently describe the ride as stiffer than I might like and underdamped (although this part was expected by not changing the shocks). I was curious of other's experiences, thoughts and advice on what they've done to improve their ride?

As a note to you disco monkey, I can't remember what people said a TD5 speedo drive outputs, and am feeling too lazy to go back a few pages to check, but if you were just counting pulses I'd argue that this is a better way to do it; takes minimal modification, and the series speedo head stays fully functioning, so you can verify your digital speed value against this; in my case I got a few of the ratio's the wrong way round and that made it really easy to spot that it wasn't right, as well as keeping your odo working for insurance purposes. *edited for meek spelling