Standard or hiflow thermostat for 02 gu td42t

[Robo]

Had a cooling issue towing and have now upgraded to a ARE alloy twin core rad.
I'm looking at the thermostat now.
daily, with towing duties big van.
Iv'e been a little unlucky in the past prior to upgrade imo with temps getting to 105 C in cool weather on a long-ish approx 1k but low grade climbs, and want to stop this sort of problem before the hot weather turns up.

I've read n read and it seems common for 100+ deg c to be seen as ok, but this is around boiling point and not ok imo.
so little perplexed on which thermostat to use.

Thermostats listed for said car.
Std is set at ----76.5 deg.
aftermarket-----80.0 deg.
a/m hiflow also-80.0 deg.

things floating around inside the little mussel.
Should I be fitting say hi flow 76 deg c ?
Is hiflow a good thing as it will allow more flow partially open, and then open more when pushed to keep things under control when hills appear?
Or just stick with a std oem unit ?

oh and egt's are good, large t/m so that's not the issue or part the problem.

Note- hi flow is recommended for towing according to it's packaging.
DSCF9030.JPG
thoughts please.

Update as the aftermarket temps were quoted wrong they should be 70deg c

[mudski]

Certainly worth a shot. Its not a big cost so I would give it a go for sure.
I think I will be doing the same to mine soon. I also have a hi flow water pump. I have just fitted a UFI radiator, larger 2 core copper jobbies, added more oil into the viscous fan clutch so it engages earlier, and change my fan to an Infinity G35 fan. Haven't taken it for a test but I might do today...
Air flow is paramount of these motors. See the big gap you have between the top of the rad and the support panel? This needs to be blocked up. Same goes for the sides. Otherwise at high speed, where mine usually gets hotter, the fast moving air just hits the rad and goes out the top and sides, and not through the rad.

[Robo]

Certainly worth a shot. Its not a big cost so I would give it a go for sure.
I think I will be doing the same to mine soon. I also have a hi flow water pump. I have just fitted a UFI radiator, larger 2 core copper jobbies, added more oil into the viscous fan clutch so it engages earlier, and change my fan to an Infinity G35 fan. Haven't taken it for a test but I might do today...
Air flow is paramount of these motors. See the big gap you have between the top of the rad and the support panel? This needs to be blocked up. Same goes for the sides. Otherwise at high speed, where mine usually gets hotter, the fast moving air just hits the rad and goes out the top and sides, and not through the rad.

Yeah I was looking at the gap all the way round also thinking the same thing.
How much oil did you add?.
I haven't pulled a viscus hub apart before, but I have some fluid in the draw ready to top up or refill.
That said its still fairly tight, I got the oil with the intention of replacing but it still only turns very minimal by hand.

Humm g35 fan, I have a gt35 skyline, same car I thought, and it runs all electric fans, so which fan are you talking about.

And the ARE rad is more open to allow better air flow so, yeah off to see if I have some stick on foam or buy some.

[Robo]

Certainly worth a shot. Its not a big cost so I would give it a go for sure.
I think I will be doing the same to mine soon. I also have a hi flow water pump. I have just fitted a UFI radiator, larger 2 core copper jobbies, added more oil into the viscous fan clutch so it engages earlier, and change my fan to an Infinity G35 fan. Haven't taken it for a test but I might do today...
Air flow is paramount of these motors. See the big gap you have between the top of the rad and the support panel? This needs to be blocked up. Same goes for the sides. Otherwise at high speed, where mine usually gets hotter, the fast moving air just hits the rad and goes out the top and sides, and not through the rad.

You replaced only the fan as the G35 fan fits the TD viscus correct?

[mudski]

You replaced only the fan as the G35 fan fits the TD viscus correct?

Hey Robo. I replaced the fan with the G35 fan, it fits the GU hub, not the GQ hub, added more oil in the viscous hub, and put in a UFI radiator. I also put in a high flow thermostat. Not sure if any of this has helped yet as its still too cold here to tell. One thing though is the fan certainly pulls more air than the OEM fan. As on start up when the fan is engaged, with the bonnet open you can really feel the air from the fan. One thing I am not sure of too is whether I have put enough oil in the hub, as this is supposed to make the hub engage earlier, being so cold here at the moment it hasn't engaged any earlier. Plenty of other people who have done this have said their fan is engaged pretty much all the time, mine isn't so I am assuming it just needs more oil. So I might have to take it off and put more oil in it. But I will wait until its warmer here first.
After speaking with a few radiator mobs and a couple of mechanics that do a lot of TD's, air flow is more important than coolant capacity. Sure capacity helps but they need more air flow. Also I will add just adding the fan and not modding the hub you will more than likely just be wasting your time. Because when the hub disengages the fan won't do anything. So you need to do both, or just the hub in my opinion if you want to see any gains.

Cheers.
Mark.

[Robo]

Hey Robo. I replaced the fan with the G35 fan, it fits the GU hub, not the GQ hub, added more oil in the viscous hub, and put in a UFI radiator. I also put in a high flow thermostat. Not sure if any of this has helped yet as its still too cold here to tell. One thing though is the fan certainly pulls more air than the OEM fan. As on start up when the fan is engaged, with the bonnet open you can really feel the air from the fan. One thing I am not sure of too is whether I have put enough oil in the hub, as this is supposed to make the hub engage earlier, being so cold here at the moment it hasn't engaged any earlier. Plenty of other people who have done this have said their fan is engaged pretty much all the time, mine isn't so I am assuming it just needs more oil. So I might have to take it off and put more oil in it. But I will wait until its warmer here first.
After speaking with a few radiator mobs and a couple of mechanics that do a lot of TD's, air flow is more important than coolant capacity. Sure capacity helps but they need more air flow. Also I will add just adding the fan and not modding the hub you will more than likely just be wasting your time. Because when the hub disengages the fan won't do anything. So you need to do both, or just the hub in my opinion if you want to see any gains.

Cheers.
Mark.

All good info, thanks.
I'll try adding some oil to the hub.
As a matter of interest the (toyo) oil comes in 3 different grades,
to lock the hub up at different temps I presume.
Is the g35 fan the type on ebay listed to suit 02/03 models?.
cheers

[mudski]

All good info, thanks.
I'll try adding some oil to the hub.
As a matter of interest the (toyo) oil comes in 3 different grades,
to lock the hub up at different temps I presume.
Is the g35 fan the type on ebay listed to suit 02/03 models?.
cheers

Got a link for the fan? As for the oil, not sure of the grades, I just bought two bottles off the one that everyone uses part number 08816-10001, 18ml bottle, and used 1 and a half of it. I did drain out what was in there, albeit not much but I think i need to add the rest. Just not looking forward to removing the fan and hub with the rad in.

[nissannewby]

Whichever way you go you need to make sure that the thermostat will close the bypass port in the thermostat housing. This helps a lot. If the thermostat does not close the bypass port when it opens then temps will rise and could be a problem.

[Robo]

Whichever way you go you need to make sure that the thermostat will close the bypass port in the thermostat housing. This helps a lot. If the thermostat does not close the bypass port when it opens then temps will rise and could be a problem.

How much should the bypass valve extend when at full opening temp?
More than the seat depth to put some pressure on seat to ensure a good seal?

But hoping problem was only lack of decent radiator.
will know more next week when I get our van back from the annex man and give it the business with new parts, fingers crossed.

I have an idea my right foot has something to do with it.
but when it first happened in cool weather something had to be done before summer.

[jff45]

Mark, how much space do you have between rad & fan with the G35? I have a 52mm 3 core rad and my G35 fan only has 15 mm space at the bottom. I moved the rad top further forward to have a bit more there.
I also put 3 x 18ml into my hub but it's never been hot enough to lock it.

Edit: forgot to add I use a 77 degree Tridon thermostat.