Series III Overheating & Gearbox queries

Hi everybody, newbie here.

Recently aquired an 83" s3 with a 2.25 military diesel engine, kinda of a company car anyway due to this I'm not sure of it's maintenance history (if any) and a few problems have come to light that I want to address. I'm reasonably knowledgeable and competent enough with mechanical stuff, but I need some pointing in the right direction.

One of the first things I did was fit a middle seat. When removing the panel under where the middle seat goes, I noticed that the flap with 4 nuts holding it down on top of the main gearbox had only 1 nut on it and there was subsequently oil around it and over the top of the gearbox. For this reason I assume the gearbox is low on fluid, can somebody advise which gearbox fluid is best and the procedure for replacing it? I've replaced the 4 bolts.

Next, the land rover intermittently overheats. There is a small water leak from the thermostat gasket so I have to top the radiator up every..50 miles or so? I've ordered a new gasket, thermostat and radiator cap. Could the gearbox being low on fluid be putting more load on the engine, causing it to overheat? The reason I'm wondering is that it heats up to just below the red when you are cruising for over say 5 minutes at 40-50mph, and when you stop at traffic lights for a few mintues and idle it goes back down to half. Also, which anti freeze and what mix is best for this engine?

I wanna do a bit of off road work soon but I'm not going too until I get it running right, so any help would be appreciated!

Ben

p.s. haynes manual on the way in the post before anybody mentions that

EP90 (GL4) for yer gearbox, remember you've a transfer box to fill with the same stuff as well. Theres a nut sticking out from the nearside side of your g/box and a similar nut on the rear of the tranny box. Remove these & fill both to the level of the filler hole.

Odd that it cools down again so quickly when you return to idle. Do you actually mean 40/50mph or do you mean 50/55mph? cuz at 55 you're pretty much flat out in a doozul III, not that it should mean you're up into the red, but I dun't know how much you're expecting from yer motor.

Have you had a good look at your rad'? The fins can rot away just leaving the capillary tubes which can lead to **** poor cooling at speed.

& welcome to LaryZone.

thanks,

i ususally sit at between 45&50, had my wee garmin GPS in the with me the other day to get the speed, my speedo was prettttyt far out. but yeah 60 in the 90 isn't too great so I won't take it any quicker.

cheers,

I think the intermittant overheating problem is likely to go away after fitting a new thermostat. I can imagine a thermostat jamming closed intermittantly. The engine should certainly not be overheating if it has an engine driven fan. Does it have an electric fan by any chance. If so, is it and it's thermostat switch working?

thanks fenby. It has an engine driven fan yup, that works. Sounds like it is the thermostat jamming, as on some trips the gauge will sit happily at half way. Have ordered all the stuff so she'll be getting a light service and all fluids topped up etc, and those bits changed this weekend. Will take her for a run and post how i get on. Cheers Again!

Ben

1 more thing qucikly, i ordered the 74 over the 82 thermostat, is that the best choice?

I have exactly the same problem, i have a series 3 (1974) and mine over heats and cools again on idle. I thought the sanme as you - thermostat so started to take top off to look and it had already been removed. The water in the rad also looks oily, i reckon head gasket has gone. Oh dear.

Is this a common prob?

Anyone

can be, not such a bad job to change you dont have to take the manifold off just gotta have strong arms

i too have a series 3 with the needle going just up to the red, but the best way to check is with a thermonitor in the rad, then run engine till temp shows up and you will be very supprised the engine will go to its hottest point and the needle is just on the red and when you check the thermomitorthe reading you get is the normal running temp as to what it says in the book

also to types of thermostat are used 1 opens later than the other1 opens at 161 degrees f and the other 1 opens at159 f not a lot of differnce but it does affect the position of the needle