Yakko

Thanks for the replies all - I really appreciate it, especially as a relative newbie on the forum. The engine does not smell hot. Putting the heaters on did not make a significant change to the engine temp (in other cars i've had, when doing this, the gauge has reacted very quickly), but the heater does blow hot air. When the engine is hot, a blip of the throttle does not cause the fan to speed up. I have not ruled out a duff gauge. I only thought of it now, but the alternator light is taking longer and longer to go out (i.e. it doesn't go out when the car is started and is idling, it only goes out after you have pulled away and the revs have risen a bit). I'll have a look at the earth strap from car to battery - perhaps it's got grubby and is causing the gauge to malfunction? So, I have an action plan for this weekend. Start the car with the bonnet open, see if the fan initially roars into life, before slowing down. Take the car on a quick run, but not up to temperature. At this point the silicon fluid should have been distributed round the fan and it should not be locked - i.e. easy to spin by hand. Get the car hot, turn it off, see if the fan is now "locked". I guess this should prove the condition of the viscous coupling? I'll also find a clean bucket to drop my coolant into (which I only replaced last week) and flush the radiator and try and bleed it properly. Can anyone point me in the direction of a comprehensive "how to" to the correct procedure? Thanks again.

Hi David, that's quite a reply, thank you for your time. Until a week ago, the temperature needle would slowely rise to vertical (so, half way round the gauge) and stop. No matter what the car was doing, crawling down lanes or being driven on the motorway, it would never go above this. Now, for the last week or so, the needle has been rising as expected, but goes well past vertical, and sits at least 2/3rds of the way round the gauge when being driven, unless the car is idling, say in very slow moving traffic, the needle will will move all the way through the white, into the black bit just before it goes red. (The first two thirds of the gauge are white, then there is a thin black bit, then the final quarter is red). The viscous fan, which I would expect to come on (kick in, lock up) by the time the needle has swung into the black section never does. In fact, if left to idle for long enough, the gauge hits the red, and still the fan idles round moving very little air. I've read that if the fluid leaks out of the viscous coupling, then the fan will feel loose, and spin easily on it's bearings. Mine does not, with the engine off mine still feels tight - there is significant resistance when it is turned. The belts are in good condition and are the right tension. I changed the coolant and thermostat last weekend, but it made no difference. The coolant was clean, there is no evidence of any oil contamination. The car is not smokey and the engine oil is clean, and shows no signs of "mayo". I will try and get hold of a decent temperature gauge, so that I can see exactly what is going on, but at the moment i've no reason to not believe the one mounted in the dash.

Ebay - good thinking. There are a few on there that I will keep my eye on. I've just brought the car to work, the car definatley gets hotter when it's stationary - which I guess points to the fan. Top hose is hot (but not so hot you can't hold onto it) bottom hose is cooler. I gave the viscous coupling a decent look this morning. It doesn't appear to have leaked, there is no sign of the fluid leaking out. Also, my second post on this thread wasn't correct. The fan doesn't spin freely, it still feels like it's guts are still in place. It isn't, however kicking in. Even sat idling after a 60 mph run on the motorway.

Just to add, with the engine off, I can spin the fan very easily, like it's not attached to anything at all.

Hi, I did do a search, can find lots of thread about their removal, but not a lot about fixing them. My viscous fan isn't working, it's not kicking in - after a run up the motorway, when left at idle the engine temperature will increase into the black section of the gauge (I know they're not accurate, but they must give a representation of what's going on) without the fan doing anything than slowely go round. This is fairly new, it's only been a problem for the last week or so. Is it possible that there could be something loose inside? I just saw the price of a new viscous coupling on Rimmer Bros, and don't fancy paying it! Cheers.

Cereal packet - genius! Will do that now, just to get me moving. Cheers.

Hi, I changed the thermostat on my 200tdi 90 this weekend, took the thermostat out before realising that although I had a replacement thermostat I had no gasket. The old gasket fell apart. I bought one from Rimmer Bros on Saturday night with a few other bits, but my order turned up today without the gasket, apparently it's on back order. Any idea where else I could get hold of one quickly? It's either that, or i'll try sticking the fragments of the old one together using it as a template for cutting one out of gasket paper... Cheers.

Is there a DIY way to get the tyre off the rim enough to get the beads in? I've got a horrible wobble at 50mph.

Sorry if i'm slightly hijacking your thread Wozzer, but I believe we have similar issues. Other than at start-up for a few seconds my 200tdi is NEVER smokey. Even at full throttle on the motorway.

I wave to all other Defender drivers - i'll wave at Discovery owners too, if they're obviously enthusiasts. I've had some ignore me, some practically hang out of the window waving back. I live surrounded by villages, on my way out one night at about 10pm I was driving down the lane only for a RRC to come bouncing down the verge out of the darkness in front of me out of the adjacent fields and woods. Got a good wave and thumbs up from him.

Hi! I'd really like that, a local get together, I am less than 5 mins from Datchworth. Paradigm Shift (who is another lurker on here) is local and i'm sure would also be interested in meeting up. Maybe someone knows some local greenlanes?

My 1991 90 (factory 200tdi) has a green cap.

That's 1.4bar, rather than psi? Otherwise there is part of your problem... My 200tdi is the same (200tdi from factory, also on 235s), it's better now i've done the fuelling mod (turning the diaphragm etc) but 70mph is still a struggle, even slight inclines at motorway speeds start slowing it down, even with the accelerator firmly against the stop. I just sit at 60 - the gearing seems to short to allow it to cruise comfortably at any faster speeds. I just assumed this is how all 200tdi 90s are.

1991 200tdi 90 - totally standard engine running 235 ATs I get 27mpg regardless of whether i'm driving like my ass is on fire round lanes or cruising at 55 on the motorway. I changed the fuelling (smoke screw and diaphragm) last weekend, so interested to see the effect on fuel consumption.

Hi! I often drive through Datchworth on my way into Welwyn - you're literally 5 mins away! Also around all day tomorrow if you need a hand getting that Nissan out.

I'm about 15 minutes away - no winch or gear (Or idea how to recover that stuck Nissan) - but i've got a 90 and a rope if you think it would any help. Also have a mate willing to come out from Stevenage with another 90 and winch if you need some muscle.

Perfect! Thanks loads - I didn't consider there might be a slot for a screwdriver in the end. Bit of a schoolboy error on my part.

Cheers, that was a quick reply! The throttle cable is now loose and I want it to idle lower. (It's always idled a bit high and adjusting the diaphragm and smoke screw seem to have made it slightly higher). I can see there's a stop that the throttle arm hits which prevents the arm from moving any further back, I guess this needs screwing back a bit to allow the throttle arm to rotate a bit more - but I can't work out how to unscrew it, it's just a piece of threaded rod (covered in 17 years worth of crud!).

Sorry if this is a stupid question, i've done a search and can't find the answer. How do you adjust the idle? I've found the adjuster, and have loosened off the locknut - this gives me a bit of threaded rod. How do I turn a 17 year old piece of threaded rod? There's not room (nor would I want to try) getting some pliers or molegrips on it. Is there a really obvous easy way i've missed? Cheers.

Got an inch at most here.

Had some snow showers today, some fairly heavy but it's been too warm and wet to settle. Supposed to be heavy snow and a bit colder tomorrow.

Screws off - if anyone finds this after searching and is having the same problem, I used a big flathead screwdriver with a pair of big molegrips locked round the handle, giving about 6 inches of leverage.

Wow, what an awesome reply - thanks! Have got an impact wrech, but not got any screw bits for it - so will try tapping the tops with a hammer to free them off. I was just going to turn the diaphragm (I'll never get used to how to spell that properly) 90 degrees clockwise - i'd read that it makes the biggest difference. At the moment the car takes an AGE to get from 55 - 70 mph and loses speed dramatically on the slightest of hills at motorway speeds. Boost levels seem ok (put a guage in yesterday) so i'm hoping it just needs a bit more fuel. The car doesn't smoke at all, even on start-up, so i'm confident there's a bit of room for adjustment. I do need to turn the idle down a bit, is it just case of loosening off the locknut and turning it down a bit? (Not easy seeing it, seems almost totally hidden by the pump) Was about to go out, but it's now snowing HARD. Cheers for all the help - appreciate it.

Good thinking on the bolts - will do that myself. When it stops snowing i'll go back out and try the screws again, they've had 24hours to soak in WD40. I pressure tested the boost gauge, fittings and hose to 2bar, so should be ok. Cheers for the replies.

Hi! Trying to get a bit more power out of my 200tdi this afternoon. Read all the write-ups about adjusting the diaphragm, going to give it a go. Trying to get the top of the pump off to get to the diaphragm, I don't know who Landrover hired to do up those screws, but I can't get them loose! I'm quickly ruining the heads of the screws. Anyone else had this problem? Any ideas to make it a bit easier (they're soaking in WD40 now). Also, put a boost gauge in this afternoon - it's making 0.8bar boost, but it builds fairly slowely. At 40mpg in 4th, will my foot to the floor, it only makes full boost at very high revs, just before I have to change gear. Is that normal? Cheers!