GUII heater core replacement

[jff45]

I’m looking at starting on this in the next couple of weeks. It’s been bypassed for the last 2 years but we plan on taking the caravan south into cooler weather in August so will probably need it.
I’m aware it’s the whole dash out which doesn’t bother me. I also know there’ll be lots of wiring to tidy up after all the stuff I’ve added over the last 14 years.

I’ve been trying to get some info on which GUs have the heater core with the tap in the plastic pipe. I think mine might be like that judging by info on Patrolapart.
Have also read that the thicker later model will fit with some slight modification to the heater box.

Has anyone replaced the model with tap and fitted the normal pipes? Problem will probably be finding the pipes without paying drug money for whole genuine core.

[mudski]

I did my GUII a while back. A bitch of a job to do. Wasn't hard just a lot to remove and refit. My GU is a 8/2001 and is uses the cheaper unit that PaP sell. Put your VIN into here : https://partsouq.com/ and this will tell you what core you have.

[jff45]

I did my GUII a while back. A bitch of a job to do. Wasn't hard just a lot to remove and refit. My GU is a 8/2001 and is uses the cheaper unit that PaP sell. Put your VIN into here : https://partsouq.com/ and this will tell you what core you have.

Cheers Mark, I did the Partsouq search last night to confirm it's the heater core with the tap. I'll wait till I have it out to see where it's leaking before I decide what to do.

[mudski]

Cheers Mark, I did the Partsouq search last night to confirm it's the heater core with the tap. I'll wait till I have it out to see where it's leaking before I decide what to do.

Is it leaking in the cab? Is yours a Ti? I’m trying to think why the cores would actually be different. Plus I honestly thought all GU Patrol ran heater cores without a tap. Having a tap would be great for summer as mine, even with all new foam sealy bits on all the diversion flaps, I get hot air coming out of the vents when it’s set to cold and the fan/ AC off. I wonder if shutting the hot water flow off to the heater core would help.
I actually thought of installing a VT Commodore heater tap in mine and some how using a servo motor to shut the water off. The VT taps don’t just shut the water off but divert the water back into the cooling system so there is no dead flow I. The cooling system.


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[jff45]

Is it leaking in the cab? Is yours a Ti? I’m trying to think why the cores would actually be different. Plus I honestly thought all GU Patrol ran heater cores without a tap. Having a tap would be great for summer as mine, even with all new foam sealy bits on all the diversion flaps, I get hot air coming out of the vents when it’s set to cold and the fan/ AC off. I wonder if shutting the hot water flow off to the heater core would help.
I actually thought of installing a VT Commodore heater tap in mine and some how using a servo motor to shut the water off. The VT taps don’t just shut the water off but divert the water back into the cooling system so there is no dead flow I. The cooling system.

Sorry for the belated response, I was taken out of action for a week.

Mine started leaking into the cabin during our return from Lorella Springs in 2019. I just pulled over and did a bypass at the thermostat housing that's still there today.
Yes, mines the Ti and, until I started to look at fixing it, I also believed GUs had no tap. It appears to be the early GUs and I'll try to research if the tap is the only difference and if it can be removed because I plan to replace it with the later model pipe if possible. I don't like the idea of putting the 20 year old tap back in and the new cores with tap (at $800) can't possibly be recent manufacture so still risky in my view.

Where do they typically leak from?

[jff45]

I did my GUII a while back. A bitch of a job to do. Wasn't hard just a lot to remove and refit. My GU is a 8/2001 and is uses the cheaper unit that PaP sell. Put your VIN into here : https://partsouq.com/ and this will tell you what core you have.

Mark, just to clarify, yours is 8/2001 and it already had the heater core with no tap?

[jff45]

Well here’s an interesting twist. I’ve just looked up under my dash with a mirror and lo and behold i have no tap on my heater core. The 2 ally pipes are clearly visible.
The Partsouq catalogue is wrong for my VIN.

[mudski]

Well here’s an interesting twist. I’ve just looked up under my dash with a mirror and lo and behold i have no tap on my heater core. The 2 ally pipes are clearly visible.
The Partsouq catalogue is wrong for my VIN.

I have the Nissanfast Program on my laptop at home. I could check that for you if you like.

[jff45]

I have the Nissanfast Program on my laptop at home. I could check that for you if you like.

Thanks but no need mate, I can easily see up under the dash that there’s no tap. Don’t know why I didn’t think to look before then it occurred to me the other day that I have a little BT borescope that might show something but tried first with a mirror and torch and surprised to see it no problem.

I’ve decided to start taking it all apart tomorrow morning..

[mudski]

Mark, just to clarify, yours is 8/2001 and it already had the heater core with no tap?

Correct...