Hey! I’m a new d40 owner. Have come across from a 99 petrol prado which I’ve learned to work out, to diesels, which is completely different and I’m hoping you guys could help with investigating a problem.
The new car was brought with an overheating problem. First thing I noticed was a pressurised cap on the radiator which has been changed to a blanking cap, but the problem is that replacing it hasn’t stopped the air bubbles coming through despite bleeding the radiator.
Now I understand they’re notorious for a blown head gasket, but these bubbles aren’t gas related as the chemical test has been done roughly 4 different occasions to check.
I’ve also noticed both inlet and outlet heater core hoses aren’t hot or even warm for that matter, which explains no heat in the cab.
The water in the reservoir is cold to touch but the hose leading to it is warm touch as well as the top of the radiator which seems odd as the reservoir is getting its water from the radiator? Or am I wrong there?
Now I’ve done a radiator flush, it was pulled out and rinsed through with a hose and has a great flow rate.
The heater core was also flushed through with the hose and seems to have a great flow rate to. It’s also not leaking into the cab.
Would this indicate they are functioning? Can they be ruled out as a problem at this point?
The car takes a roughly 5-10 mins to heat up on idle, it’s been taken for a spin (after attempting to bleed air from radiator) and she has not overheated but noticed the indicator started to climb after running at around 85/90 for about 2 minutes and being careful we’ve backed off on speed and she’s immediately gone to normal operating temp.
The symptoms are confusing me, on one hand a mid stuck thermostat could be the reason she takes her time getting to normal operating temp.
If the inlet to the heater core isn’t even warm then I believe the issue to be somewhere before the heater core but after the radiator as it’s hot.
There are no noticeable leaks. The only time she loses coolant is when the reservoir becomes pressurised, having coolant leak from the pressure point (not sure of the name but the nozzle at the top where the lid is) which is caused by air gaining access to the cooling system or being present still but where and why.
Is the valve for the heater core not working and that’s why the heater in and outlet isn’t hot?
She’s been bled a ton, and I don’t want to start replacing everything that doesn’t need replacing in the hopes I’ll find it.
So I guess I’m just looking for potential causes before it becomes heater core replacement and thermostat and maybe temperature sensor then posibile faulty hoses. We all know parts for these beasts aren’t cheap! So what are your thoughts and what is the best way to test them or best symptoms to search for.
Please help me understand how it all works and your general thoughts on what it could be.
Also to note, after having done the last air bleed tonight, there was no sign of bubbles coming up through the reservoir. I’ve yet to take her on a decent drive around the block to find out if it’s fixed anything only because of the symptoms above (heater core hoses and reservoir water was still cold) still being present after bleeding the air. Just makes me a bit worried the problem which causes the temp gauge to climb at a higher speed might still happen and indicating the problem wasn’t located.
Also thankyou to anyone who’s taken the time to read this!
The new car was brought with an overheating problem. First thing I noticed was a pressurised cap on the radiator which has been changed to a blanking cap, but the problem is that replacing it hasn’t stopped the air bubbles coming through despite bleeding the radiator.
Now I understand they’re notorious for a blown head gasket, but these bubbles aren’t gas related as the chemical test has been done roughly 4 different occasions to check.
I’ve also noticed both inlet and outlet heater core hoses aren’t hot or even warm for that matter, which explains no heat in the cab.
The water in the reservoir is cold to touch but the hose leading to it is warm touch as well as the top of the radiator which seems odd as the reservoir is getting its water from the radiator? Or am I wrong there?
Now I’ve done a radiator flush, it was pulled out and rinsed through with a hose and has a great flow rate.
The heater core was also flushed through with the hose and seems to have a great flow rate to. It’s also not leaking into the cab.
Would this indicate they are functioning? Can they be ruled out as a problem at this point?
The car takes a roughly 5-10 mins to heat up on idle, it’s been taken for a spin (after attempting to bleed air from radiator) and she has not overheated but noticed the indicator started to climb after running at around 85/90 for about 2 minutes and being careful we’ve backed off on speed and she’s immediately gone to normal operating temp.
The symptoms are confusing me, on one hand a mid stuck thermostat could be the reason she takes her time getting to normal operating temp.
If the inlet to the heater core isn’t even warm then I believe the issue to be somewhere before the heater core but after the radiator as it’s hot.
There are no noticeable leaks. The only time she loses coolant is when the reservoir becomes pressurised, having coolant leak from the pressure point (not sure of the name but the nozzle at the top where the lid is) which is caused by air gaining access to the cooling system or being present still but where and why.
Is the valve for the heater core not working and that’s why the heater in and outlet isn’t hot?
She’s been bled a ton, and I don’t want to start replacing everything that doesn’t need replacing in the hopes I’ll find it.
So I guess I’m just looking for potential causes before it becomes heater core replacement and thermostat and maybe temperature sensor then posibile faulty hoses. We all know parts for these beasts aren’t cheap! So what are your thoughts and what is the best way to test them or best symptoms to search for.
Please help me understand how it all works and your general thoughts on what it could be.
Also to note, after having done the last air bleed tonight, there was no sign of bubbles coming up through the reservoir. I’ve yet to take her on a decent drive around the block to find out if it’s fixed anything only because of the symptoms above (heater core hoses and reservoir water was still cold) still being present after bleeding the air. Just makes me a bit worried the problem which causes the temp gauge to climb at a higher speed might still happen and indicating the problem wasn’t located.
Also thankyou to anyone who’s taken the time to read this!
