SLROC Forum

Got that 2 bottle radflush stuff today on way home from work as i think the 300tdi radiator was bunged up. Here is what i done.
Started by emptying out all the new coolant mix i done when fitting the engine. Right enough it was manky full of floaters  .
As instructed took of the thermostat put a pipe in there and undone both radiator bung and bottom hose and flushed engine block lots of manky horrible stuff came out. Refitted bottom hose and filled entire sytem with fresh water and bottle 1 radflush. Booted it down to galasheils and back.
Empty out radiator again and block more crap came out. flushed entire system with fresh water then filled with fresh water and added bottle radflush2.
Booted it to temple area and back. Got home emptyed system not much crap this time so final flush useing fresh water and filled with coolant mix 50/50 ratio.
Now i get lovely heat from the heater as i run it full pelt whilst bleeding. Temp guage is sitting below half way rising to 3/4 under heavy throttle. Heater always stays warm. Slight weeping from expantion tank. I fill the system via the thermostat bung then radiator then top the expantion is that right?
Here the weird part. Bottom hose cold, top hose warmish, expantion tank warmish , heater pipes boiling, thermostat housing empty when bung removed to check. If vehicle pointed up a hill things get better how do i get the sodding air out the sytem?.
Cheers.
Scott

hi bud,you should have a small plug ontop of rad i think its a 24mm fits remove that when you are filling water/coolant this should bleed system,i think by the sound of things you have more problems but hard to say over email,check water is passing through rad ok it does not take alot to block,then you can remove thermostat and dip in boiling water check it opens about 75,if all thats ok then you can do a pressure test to make sure your head gasket is ok,if you cant get a test kit get a clear bottle fill with water get a small pipe and stick one end in expansion bottle and one end in your clear bottle make sure both end are below water,run the engine and wait till it warms up if you get bubbles in your bottle you got problems,hope this helps,please check rad very carfully.

Thanks for the advice Araon
Ill work through the  tips im certain its a radiator problem engine had a new bottom end and top end rebuilt less than 10000k ago with no water loss or collant in sump or oil used. Im gona be might annoyed if it is the cylinder head though. Certanly does not lack power and never misfires etc. Get back to you after checks.
Scott

  Now im out of ideas and dont know what to do next.
So fitted new thermostat. Changed sender to specific "Black" sender ament to be the one for disco converted engines into defenders.
Still reads medium to high on the guage.
HAve noticed if im driving around slowly its fine. If im driving up a steep hill nose of truck in the air guage suddenly drops.
Heater works fantastic nice and warm. No air bubbles in the expantion tank if cap left off and allowed toi warm up.
Expantion tank level will raise to almost max but never really overflows. All pipes hot apart from the 3 way bottom hose. The samller section to the thermostat water pump area is hot the larger section to bottom of radiator is cold and the medium section to expantion tank luke warm.
Radiator warmish all over.
Any ideas guys?
Cheers.
Scott

I wouldnt leave any cap off to look while it warms up,
its a pressurised cooling system.

(No hot water should flow untill the thermostat opens when the engine coolant reaches running temp,
well only a little from the thermostat anti airlock hole)

If the radiator is clear with no blockages, & its the correct thermostat & you are running this now with the correct Antifreeze/summer coolant/rust inhibitor ratio to give the correct coolant temp,
lets start.

Is there not 2 bleed points on your 300tdi??

Are you bleeding right around the system is the heater controls closed at present?
(to make it simpler to see if the system can be bleed minus bleeding the heater.)

If there is a problem is it an air block at the thermostat or a collapse/blockage in the radiator or intercooler?

Both bleed screws open if there are 2, fill up with coolant, (dont overfill)

Shut bleed screws.
Cap on.
Engine run untill its at the correct temp with the coolant in the engine block circulating on ly in the block
untill up to temp.
(as should happen),
only a little heat goes past the thermostat if it has a little hole, as it should)

When the engine is at temp & the thermostat opens the hot water will flow past the thermostat.
Take it for a gentle run to circulate the coolant,
stop & bleed at the highest bleed hole.
*Kind of obvious, but you can only really bleed the system when its hot enough & the air is steam*

Run it home & leave it to cool down, dont open the cap untill cold.
If it needs a little top up, do this.

Repeat the procedure if it needs bleed further, or you need to do the heater with the controls open to allow coolant around the heater.

Always run Antifreeze, it alters the boiling point.

Always works for me.
Might not be the 300tdi procedure tho.
Hope someone corrects me.

*let a pressurised system pressurise & set its level via the overflow or pipe back to the coolant bottle.*
A working pressure cap should blow & allow an escape of coolant if required.

george

Thanks george
Like all the advice given so far on this problem i will follow evry step see if it helps. you mention possible air blockage at thermostat well i did open the bleed cap thats by the thermostat one time and it was completly empty of water. See how i get on thanks again.
Scott

by the sound of things you have a circulation problem,you can remove thermostat and sit in a cup of boiling water to see if it opens but its starting to sound like rad fault,if you remove rad and flush with hotwash it maybe clean out but you better to go to rad specialist and get it opened and check,as i have said very hard to tell over net but this is the road i would take,i have had a fault just like this before and i hot washed the rad but i ended up getting it repaired

Yip i agree araon just getting the cheap checks out the way first. I know the engine was fine prior to the swap and had no overheating issues. The radiator might have been damaged when it was stored..Have a new radiator on order they ahve delivered the wrong version 2 times now. Truck broke its front propshaft yesterday so gota buy new props first lol it all happens at once... engine does pefrom very well though. Cheers for the advice ill let you know how i get on.

hi scott my 300 converted runs just over the halfway mark on the temp gauge and seems happy, we can compare them sometime if it would help, has your diesel pump been tweeked ? when i got mine the temp ran up around 3/4 and above, eventually found the pump main fuel screw had been turned up, from the web this causes 100 degree c temp rise in the engine for each quarter turn, i turned it back problem solved, also which transfer box do you have in ? if its the old  one from a 2.5na 1.6 ratio i think, it will cause the motor to rev its nuts all the time and overheat, mines did that till i put a disco transfer box in it 1.22 ratio, ideally you want a 1.4 transfer, if you retained the lt77 gearbox instead of r380 that may be different tho, if i you have lt77 maybe someone else can tell you the corrct ratios

Hi
Thats a great offer not sure were your based but im just outside edinburgh. I have the disco transfer box on the back of my lt77.
As for tuning cant answer i asumed is was a standard setup engine seemed nothing fancy in the disco when it was test driven. Does spool up very quickly though due to the airfilter mod dont know if that may cause things to run hot.
Pretyy certain its not an engine fault and more a blockage somewhere just gota work through it all.
Thanks.
Scott

i am just over the bridge in fife , if you don't get sorted we can do something next week

Thats great thanks . I have to fit new propshafts first though the old girl decided she did not like the old ones 

So been useing the 300tdi a fair bit latly. Drove down to the event at the forest estate it was fantastic  .
As for the landy well she seems to be behaving well kind off. Offroad she did not heat up at all nice and cool no need for fan.
On slower runs about 40-50 the same nice and cool.
60+ and she does warm up but never goes into the red and i dont get any pressure release from the expantion tank.
I have noticed its when the turbo is at full chap the heat rises. Got a new radiator to fit aluminium core if that makes a diffrence. Going to fit it on next week along with possibly a new intercooler.
Was speaking to a trucker and he reakons the intercooler aint suited now the turbo spins up more freely along with the almost straight through exaust.
Maybe its just the dial i dont know will get to the bottom of it sooner or later.

worth checking its not overboosting as well , 1bar is max on a 300tdi without other mods, also any tweaking of the pump greatly increases the temps, also transfer ratios if its on the old ratio box it may be revving too high