PK Heater not operating - what am I missing here??

duza
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Joined: September 1st, 2006, 8:57 am
Location: Dural, NSW

PK Heater not operating - what am I missing here??

Unread post by duza » July 2nd, 2018, 9:47 pm

Haven't posted for many a day, but have a cracker for you boys to solve.
I have a 3lt PK Ranger which goes really well except the heater does not get hot.
If I disconnect the hoses into the heater I can pour water thru the heater core and all is good. However, if I then start the motor and bring it up to operating temp with those hoses disconnected, there is no water flowing out of the hoses from the engine, so I guess the heater can't work ever if no water is present.
If I bypass the heater core altogether, by joining the 2 hoses with a piece of clear PVC pipe, I can see no water flow.
So, I removed the thermostat and repeated the exercise. Still no water flowing from the 2 pipes. Removed the water pump. Looked good, but replaced thinking the fins could be worn and not pumping enough to lift the water into the heater core.
No change.
Could it have something to do with the EGR cooler? Disconnected the pipes at the top of the motor going into the EGR cooler. No water. Bloody hell!
Engine appears in very good condition with no corrosion. When I removed the old water pump, I poked a wire from the water pump housing into the thermostat housing and it is unblocked. If I pour water into the top radiator hose where it enters the motor, it freely runs straight thru the motor and out the bottom end, so the block seems fine.
WTF am I missing here?
Please help. This is driving me nuts.
Regards,
Ric

cbd
Here and there
Posts: 72
Joined: November 17th, 2017, 7:38 am

Re: PK Heater not operating - what am I missing here??

Unread post by cbd » July 3rd, 2018, 7:05 pm

G'day
I checked mine (PJ) one passes down and a he passenger side and enters the firewall. The other is a bit passes from the top of the motor on the drivers side and again straight through the firewall. There is no external tap that I can find.
I dropped down the glove box by pressed the back tabs so I get t a clear view behind it still no regulated tap! Recon that regulator tap must be directly behind your main Bessel? That could be the problem.
It isn't under pressure flow part of the cooling system but by disconnecting both hoses and connecting one one to a running garden hose it should run with the heat dial turned up ie open?
Sorry havn't yet figured how to get that Bessel off as yet.
Tell us how you go

duza
Been here a while
Posts: 285
Joined: September 1st, 2006, 8:57 am
Location: Dural, NSW

Re: PK Heater not operating - what am I missing here??

Unread post by duza » July 3rd, 2018, 8:19 pm

The Ranger does not have a tap. The hot water flows thru the heater core continuously. There is a control door which controls the amount of heat coming from the core and going into the rest of the heater box then out via the fan.
No, I have determined there is nothing wrong with the heater mechanism. I have had the whole dash out and dismantled the heater and tested the core. Big effing job. It is unclogged and passes water freely. I can even blow air thru it with my mouth.
So, that then led me to start testing under the bonnet and hey presto no water flow up to the firewall. So, then thermostat and water pump, poking wires thru the block and testing water flow thru the block. No corrosion. All seems Ok, but still no water flow to the firewall. It's almost like the water pump is not strong enough, but it is new and acts the same as the old one. I understand a water pump is not really a pump but is in fact just a swirl mechanism which helps the water to proceed around the engine and heater. What the pressure in the system does to promote that flow I am not sure about and maybe I need to do a pressure test of the system. Maybe, if you leave the radiator cap off any motor and therefore have no pressure within the system, any car would have the same problem. In other words if there was a pressure leak resulting in nil pressurisation then there may not be enough water flow to get up to the heater. But there is no water leak in my system. I drove from Sydney to Yass last week and checked the water level on arrival and it was full, so I suspect a pressure test will not provide any answers.
I don't know this has got me stuffed. I must be missing something, but what?

cbd
Here and there
Posts: 72
Joined: November 17th, 2017, 7:38 am

Re: PK Heater not operating - what am I missing here??

Unread post by cbd » July 3rd, 2018, 8:42 pm

G'day
Thanks for the reply. Very detailed.
It's pretty obvious that this system operates a bit diferent that what I'm used too.
question? Does the car heat using the air conditioning button? Why I ask is these systems do not have a replaceable pollen filter. Could it be lack of air due to dust block? Or fan strength? I've read something on cleaning reciently, I'll try to track it down and get you a link.

cbd
Here and there
Posts: 72
Joined: November 17th, 2017, 7:38 am

Re: PK Heater not operating - what am I missing here??

Unread post by cbd » July 3rd, 2018, 9:20 pm


duza
Been here a while
Posts: 285
Joined: September 1st, 2006, 8:57 am
Location: Dural, NSW

Re: PK Heater not operating - what am I missing here??

Unread post by duza » July 3rd, 2018, 9:58 pm

Thanks for the link. When I had the dash out, I dismantled the whole heater, air con assembly and it was all very clean and no, the air con on does not heat the vehicle, only cold air all the time, no matter what the controls are set at..
No, the problem is: no water flow thru the heater pipes equals no hot air ever.
Why this is not happening beggars belief.
Most people would know that if you were to get a crack in a heater hose near where they enter the firewall, pretty soon all the water in your system would be on the road and you have a very hot motor. This thing means you can leave the hoses off altogether and there will be no water loss. Admittedly, I haven't actually done that yet, ie gone for a drive with the hoses off, I have only idled the motor for 20 minutes or so, until the temp guage is well and truly at operating temp. Maybe now with the new water pump I should try that and see what happens. Stay tuned.
Ric

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