Which pipe? Hoses don’t collapse. If anything their pressurised with airNext step would be to check the temps Rad outflow hose. Also, when it's running set up a camera (or have a friend) monitor the hoses and give the engine some quick throttle inputs. You're looking to see if any of the hoses look like they're sort of collapsing on themselves.
This can be indicative of blockage assuming you don't have any long supplemental coolant lines running to heaters in the back of your Defender.
Yes, this or just remove the thermostat and see if the engine heats up still.Punch a bunch of holes in the thermostat/cut the spring it will circulate, if you are worried about getting a decent seal.
J
Do you mean bleed by loosening the clamps on pipe or by loosening the cap. I’ve tried bleeding through the capYes, this or just remove the thermostat and see if the engine heats up still.
You can also bleed the coolant lines at the thermostat housing.
I meant the cap.Do you mean bleed by loosening the clamps on pipe or by loosening the cap. I’ve tried bleeding through the cap
Why?definitely check any heater matrixes
Because that is where there are often airlocks that peeps don't see or think about.Why?
A car doesn't overheat without a heater matrix?
J
Because that is where there are often airlocks that peeps don't see or think about.
I have a 300tdi but have never had an airlock or voer heating, but it is always worth disconnecting the heater matrix at one end or the other and then checking it fills properly before reconnecting.If its an airlock in the heater it should not stop circulation to the main engine rad. Does it? I dont know the 300tdi.
J
The main rad don't get hot allover .I have a 300tdi but have never had an airlock or voer heating, but it is always worth disconnecting the heater matrix at one end or the other and then checking it fills properly before reconnecting.
I don't know how important the cooling from the heater matrix is to the whole system, but it must have a bit of an effect at least. There is as far as I know no old fashioned tap to turn it on or off. If you can "short circuit" it and there is still sufficient coolant flow and cooling effect, then it'll make no difference. But checking it can't hurt.
Think maybe he needs either a better flush of the rad or a new one.The main rad don't get hot allover .
Airlocks are always an issue but OP has seemed to have got that.
J
I did a long journey the day before with heating on a lot. I did reverse flushThink maybe he needs either a better flush of the rad or a new one.
Hope he did reverse flush it. number of times I've fixed overheating on older cars just by doing that. Wonder if he had done a long journey or two before this happened as in my experience this is what dislodges the carp from elsewhere in the system and flushes it into the rad where it sticks and blocks passages.
OP did say that the cab heater will blow warm air momentarily but then it's cold - symptoms of a blockage or air lock.The main rad don't get hot allover .
Airlocks are always an issue but OP has seemed to have got that.
J
As there are so many waterways in a rad, it may appear to be succesful as water flows out of the other end, but it could just be flowing through the unblocked tubes.The compression test was done on a warm engine. The pressure test was done without any coolant in. I’d have thought that there would be no change.
Without a thermostat fitted air came out the housing. As I flushed the radiator successfully I discounted a blocked rad.
I know it is a pain to get to and he'll need another P gasket but maybe worth checking. But I hope he can find a really good flushing agent take the rad out and leave the flush stuff in it overnight with the rad full, then try flushing again. doing it on the car can work but I have done that to no avail until I took it off, flushed it turning it in all directions and banging it gently until all the crud has come out.OP did say that the cab heater will blow warm air momentarily but then it's cold - symptoms of a blockage or air lock.
Could it be the impeller on the water pump has come off and is sitting in the housing? This would be a minor blockage and would reduce flow
LAND ROVER 300tdi Water Pump Housing ERR3736
The reason all that was caused was overzealous tighneting of bolts to fit the alternator caused it to crack and leak it looks like the P gasket but the casing has split just above the p gasket. We deduced coolant in the bolt hole and excesive force on the bolt caused this whole mess!
Correct stat fitted?it should have an extra bibble to cut off the bypass circuit as it opens.I like your thinking. Probably because you’re saying it doesn’t sound like HG. I’m going to remove the thermostat as turboman suggested but I wasn’t getting a perfect seal. I guess I can remove the rubber from the thermostat and fit that to seal it up. To my mind the fact the thermostat housing to rad pipe gets hot is saying that it’s opened the stat just not flowing
Taking it off and flushing may be worthwhile. Thanks. Otherwise I can only think it’s the water pump.I know it is a pain to get to and he'll need another P gasket but maybe worth checking. But I hope he can find a really good flushing agent take the rad out and leave the flush stuff in it overnight with the rad full, then try flushing again. doing it on the car can work but I have done that to no avail until I took it off, flushed it turning it in all directions and banging it gently until all the crud has come out.
In both cases it was a case of it having happened after a long journey. In one case from Scotland to Lille in a Morris 1000 van!
And no neither vehicle was mine!
the head was pressure tested hot.Correct stat fitted?it should have an extra bibble to cut off the bypass circuit as it opens.
Just because wpump is new should not discount it from your tests.
Viscous fan still fitted?
How did you bleed it?
If all else checks out I would get the head pressure tested with it hot.
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