Nissan Patrol 4x4 (Africa)

I have a strange problem, the metal pipe to the front of the starter motor leading to the heater (I presume), picked up a small crack on the way to the Namib, which they welded in Keetmanshoop. (Fortunately I picked it up before the car lost too much coolant and the engine temperature never climbed above normal.) They had to partially drain the coolant and I am not sure if the system was properly bled. The car runs at a very stable temperature, a little below normal and the coolant stays full. However, when towing or driving a long distance, I hear a boiling sound for a short while after stopping and swiching off, while the guage remains at normal. There is also no sign of water leaking or boiling. When I start again, it feels as if the heater comes on for a while. We, unfortunately, do not have any Patrol specialists nearby so I hope one of the specialists on the Forum has advice.

The system is designed such that, in the event of a small boil, it will be contained within the reservoir. Next time you hear it, unscrew the reservoir's cap and see if steam is emitting from the small pipe coming from the radiator.

If this is the case, it isn't necesarily a problem, because the water will be sucked back in as the engine cools, but it might be pointing to a radiator cap that is busy failing.

As far as I know, the heater matrix on the Patrols always has water flowing through it, and switching the heater on and off merely moves a flap to direct air either through or past the heater matrix. Certainly, my GQ doesn't have a valve in the water system that i've ever been able to find.

If the 4.8's system is the same, it could mean that neither of these two issues is related to the cracked pipe or it's repair, and the heater is merely a solenoid or mechanism that is growing a little sticky...

DanieG wrote: ↑07 Oct 2017 13:01 I have a strange problem, the metal pipe to the front of the starter motor leading to the heater (I presume), picked up a small crack on the way to the Namib, which they welded in Keetmanshoop. (Fortunately I picked it up before the car lost too much coolant and the engine temperature never climbed above normal.) They had to partially drain the coolant and I am not sure if the system was properly bled. The car runs at a very stable temperature, a little below normal and the coolant stays full. However, when towing or driving a long distance, I hear a boiling sound for a short while after stopping and swiching off, while the guage remains at normal. There is also no sign of water leaking or boiling. When I start again, it feels as if the heater comes on for a while. We, unfortunately, do not have any Patrol specialists nearby so I hope one of the specialists on the Forum has advice.

Normally if the cooling system makes a boiling sound but your Temp Gauge is normal, then its a coolant flow problem.
I had It on a Golf 1. I took the small pipe that's on the top of the Rad that leads to the bottle off, and it was blocked.
The min I cleared it out then the trouble was over. So that Patrols cooling system sounds as if the flow is a bit restricted and because of that its not cooling down fast enough.

Louis Nel wrote: ↑02 Jan 2018 15:11

DanieG wrote: ↑07 Oct 2017 13:01 I have a strange problem, the metal pipe to the front of the starter motor leading to the heater (I presume), picked up a small crack on the way to the Namib, which they welded in Keetmanshoop. (Fortunately I picked it up before the car lost too much coolant and the engine temperature never climbed above normal.) They had to partially drain the coolant and I am not sure if the system was properly bled. The car runs at a very stable temperature, a little below normal and the coolant stays full. However, when towing or driving a long distance, I hear a boiling sound for a short while after stopping and swiching off, while the guage remains at normal. There is also no sign of water leaking or boiling. When I start again, it feels as if the heater comes on for a while. We, unfortunately, do not have any Patrol specialists nearby so I hope one of the specialists on the Forum has advice.

Normally if the cooling system makes a boiling sound but your Temp Gauge is normal, then its a coolant flow problem.
I had It on a Golf 1. I took the small pipe that's on the top of the Rad that leads to the bottle off, and it was blocked.
The min I cleared it out then the trouble was over. So that Patrols cooling system sounds as if the flow is a bit restricted and because of that its not cooling down fast enough.

The heater comes on and off at random while travelling, which is highly annoying. I read on an Aussie website recently of a 4.8 having exactly the same problem after flushing the cooling system. Apparantly the system has to be bled at a screw in front of the cylinder head to release all air. Does anybody have more info on that, I do not want to start unscrewing the wrong bolts.

My radiator cap failure started exactly like that - we pushed the vehicle in the sand, but temp gauge remained normal. When I switched off, I heard a boiling sound which was in fact water / air blowing back through the cap into the plastic reservoir. While driving normally over the next two weeks, I never heard anything again - until driving back home, 38 degrees and pulling the trailer, and without warning all the coolant was pumped out of the radiator, through the plastic bottle and out onto the road !!!

The heater comes on and off at random while travelling, which is highly annoying. I read on an Aussie website recently of a 4.8 having exactly the same problem after flushing the cooling system. Apparantly the system has to be bled at a screw in front of the cylinder head to release all air. Does anybody have more info on that, I do not want to start unscrewing the wrong bolts.
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Graham should know all about that on how to bleed the cooling system.
His number is 083 417 7503. I've never been to him personally but from what I have read on these forums, he is the man
to see when it comes to Patrols. And if I'm not mistaken, always solves the problem!

het die 4.2 ook so n screw om te bleed

Shalom

Jules I assume you mean the 4.2 Petrol.... The TD42 has a bolt/screw thingy on the top of the thermostat housing that one can bleed the system from, but on mine I just parked on an uphill and slowly few the coolant into the radiator till it was full. The system will self bleed as long as the radiator cap is functioning 100% ( obviously thermostat too)

Nie wat ek nog ooit kon kry nie Jules

Right at the back against the fire wall is a bleed pipe on the 4.8. Its not a srew. Just blanked off with a cap. But its the highest point on the water system. I bled mine with it and there is no issues.
My reason for bleeding was not overheating but a pipe that needed replacement. Hence I lost water and had to refill.