I really could do with some real help here...
I have absolutley...NO LEAKS thats for sure.
I have flushed the system, I have de-scaled the system.
I have SLOWLY re-filled the system.
STIll the temp gauge creeps up into the red...WHY??
One thing i have found is that when i take the rad cap off, the water has dissapeared...so i top it up, and to my surprise.....I can sit there and watch the water level go DOWN...Soooo i top it up, and then watch it go down ...its NOT a great lot, but wheres it going???
Like i said i have NO LEAKS....could it be something to do with the thermostat, not fully opening??
I'm NOT a mechanic so just guessing here.
thanks (again)
Jeffers
- (#11909) Jeffers, 3 Jul 04 12:59
It looks like you either have an air lock or blockage in the system. I had exactly the same probs with my Spacecruiser. Tried everything to solve it but nothing worked. I eventualy discovered that it was a partialy blocked radiator caused by me putting rad weld into the system to cure a leak that I had while motoring down the M6 from holidaying in Scotland. I have since been told by other owners of Spacecruisers and Townies that they also had overheating problems after using rad weld.
- (#11909) James, 3 Jul 04 16:36
I had the same thing ended up costing me a lot of money trying to find out what it was. It ended up as a blocked radiator and a tired viscos fan. causing the problem. the light kept coming on telling me the water had dropped in the header tank again and again i flushed the system and refilled it,again and again it happend until eventually i had to take it in we swapped the head gasket and had it pressure tested ...nada....then out came the radiator and the right side lower quater was solid. that radiator is at an angle and the silt had built up over 13 years and would not have shifted with plasic explosive. Off it went to sercs and they soaked it in coastic soda for a week and it still wouldnt budge and so it was recored. End of problem. Now im having the turbo replaced !!
My advice is dont mess around with it take it to a ruddy good diesle fitter and tell him to check it over and have a bloody good luck at the radiator and heater matrix and suggest he try a really high pressure back flush to see what comes out. You can try yourself of course but take the thermostat off and the bottom hose and really blast it. Of course it may not get it all out if its solid but it will give you an indication of what its like in there. Whatever you do dont use descaler mind. Hope that helps
- (#11909) steve, 3 Jul 04 17:16
It is difficult, at a distance, to pinpoint what might be happening but, there are essential procedures with this coolant system, which should ensure satisfactory operation and you are right, in my opinion, to suspect the thermostat. Obviously, while you are watching the water level, the engine is not running and the thermostat is closed. In the thermostat there is a small bypass called a "jiggle valve" which should allow some coolant to pass through the thermostat, irrespective of it's temperature. The descaling might, unfortunately, have allowed a build up of scale and sludge at this low point in the system and might, nearly, have blocked this valve, therebye giving the symptoms which you are experiencing. Also, and there is a lot in the archives about David Millers experiments with the thermostat, one or two 3mm drillings, in the thermostat flange, makes all the difference on these cooling systems and I think, in your case, the next move should be to replace the thermostat with a suitably modified one.
The system benefits from really slow filling, a "back flush" of the radiator with the top and bottom hoses disconnected, a really thorough check on the integrity of the feed/return hose into the expansion tank and a thorough check on the rear heater flow and return.
Also, abandoning the standard temperature gauge and replacing it with a Durite or, fitting one of Dave Mason's sophisticated indicators, will allow a much better indication of what is happening.
- (#11909) John Davis (Leics), 4 Jul 04 01:06
As has been said by others, it could be the thermostat. I replaced mine last year with an aftermarket stat that had a 25 mm opening, and was sticking on opening and closing. When I swapped it out for a Toyota 30mm stat, the overheating was cured. Whilst your at it, get a new thermostat Oring and change the radiator cap for the latest Toyota float type.
- (#11909) dave Bright (Bournemouth), 4 Jul 04 09:07
Ey-up, I've just cured mine and had EXACTLY the same issues. You say you've no leak. Chances are you have. Mine started out with a small hole top-centre of the vertical rad (4WD RL). At first (several weeks) I couldn't find a leak anywhere. Turns out losing such a small amount it was evaporating whilst running down the (very hot) rad. This only got noticed on dark night when I needed to top up the expansion tank (again) after the warning light came on. Being dark I had a torch and that was when I noticed the steam coming from under the fan cowl.
The only time it tended to boil up (and this long before the needle moved much passed half way) was under load, ie full of bodies (live ones I might add).
To cut a long story short (????? yea, right). Had the rads out & re-cored (oldham radiators, highly recommended) new stat,flush blah blah and now she will climb everest without so much as a pant, 70mph, no prob. That needle never budges, not a drop lost and stays cooler than a cool thing. The best £300 quid I ever spent on the rig & I would recommend anyone to do it to one of these things. In fact, when you buy one and do the obligatory cam belt, rip the rads out while you're there and have them re-cored and the system flushed and you will be one seriously happy bunny, poor but happy.
Dave B
- (#11909) Dave B, 7 Jul 04 12:18
Err, just one more point about your topping up. If your system is as choked as mine was, think about just how long it would take to drain through a rad that has clogged sponge in the vains. You could sit there for days and still not have filled the system, it just slowly sinks away. When we drained my system less than 4 litres of coolant came out. Believe me there was a bloody sight more went back in after the job was done, it more than that in antifreeze to get a 50-50 mix.
- (#11909) Dave B, 7 Jul 04 12:27