Tuesday, September 23, 2008 - 03:46 pm, by: Tai Johnsen(Privatejohnsen)
I'll start by saying I am running separate engine management (adaptronic) and using factory sensors for it's inputs.
Here is the scenario..
The Dash temperature gauge reads the same as it always has, 1/2 way or a poofeinth (1 notch) above the 1/2 mark... No problem right..
BUT, the adaptronic registers the engine temp at a nasty 105 degrees plus.. It's never boiled, so I just thought the adap was reading the temp wrong and needed calibration.
So I bought the VEI system temp gauge and temp sensor and did a boiling water test with a known fluke multimeter and thermocouple. Bang on the mark all the way down..
So I put it in, and bam... 105 - 106 degrees..
The dash still reads 1/2 way...
The hyrdo fan doesn't ever seem to speed up since I installed the adap as far as I can remember.
Is there an easy way to test the fan speeds? Activate the solenoid somehow to see if it drops the temperature?
Other than that, I guess it could be the thermostat or water pump. Whats the easiest way to check those out?
Tuesday, September 23, 2008 - 04:09 pm, by: Tai Johnsen(Privatejohnsen)
Here is a pic of the water temp position.
It might also be worth noting that the radiator cap was quite hard to remove... Like the sealing rubber was too big in diameter for the housing.. Should I replace it?
Tuesday, September 23, 2008 - 07:20 pm, by: Neil Griffiths(Aussiesc)
Genuine Cap is CHEAP .88 kpa pressure ( TT .9 )
Imagine what my temps are when the stock gauge BLINGS and the dial is off the top when I race a Wakefield..hahah Pour water in after awhile,then race again Then drive home.
There is a test you can do on the stock fan ( Look up LS400 manual )
It has 2 speeds ( You will never see top speed with the hood up ) ( Both these are in the Diag connector )
Fan ECU is behind the glove box attached to the heater box.
Wednesday, September 24, 2008 - 03:18 pm, by: Jeff Bedsor(Jeff_bedsor)
Get a 72 degree TRD thermostat, that helps a bit. Mine is much the same, the gauge in the dash never moves, but the Autometer one can vary from 80-95degrees.
Thursday, September 25, 2008 - 03:30 pm, by: Tai Johnsen(Privatejohnsen)
Thanks Pete I was pretty pleased when I found the info, and that it worked..
Unfortunately it hasn't helped solve the problem..
The radiator is coming out and getting a clean..
I found a mob nearby who hand clean the cores out for $88, so i'll wave goodbye to the $40 worth of coolant i've put in it over the last two days and see if this fixes the problem. (fingers crossed)
Would there be any issues with running the jumpers for the fan permanently? For instance if you are going up a mountain range, rig a switch up to set the fans on flat out..?
Thursday, September 25, 2008 - 03:46 pm, by: Peter Nitschke(Pen)
As I see it, jumping the fan would only be masking another problem that might be getting worse.
My experience is that even on really hot days, as long as the car is moving the big radiator cools quite well without needing the fan.
What would bother me a bit, is that if the radiator is clogged, then the cooling system hasn't been maintained - not had the proper coolant etc. So what condition is the heater matrix in? Don't read this if you don't like to worry!
Thursday, September 25, 2008 - 08:21 pm, by: Tai Johnsen(Privatejohnsen)
The gauges are 52mm. I reckon they are sweet, they have standard brightness setting, headlight dim, max range settings, boost peak hold, high and low temp alarm, pretty cool.. They were like $80 each when the exchange rate was good..
I am not going to try to "fix" the problem with the jumper, I just thought it might be a handy feature to have if the temp was climbing and there wasn't anything you could do about it...
I generally try to do things the right way
Should I worry about the heater matrix? The heat still works..... Don't they leak or something?
If it started to leak, i'd probably block it off somehow, as long as the A/C still worked!! Haha
It could still be the water pump, but I haven't seen anything saying how to test it yet.
Friday, September 26, 2008 - 08:47 pm, by: Tai Johnsen(Privatejohnsen)
Thanks Matt, I can see water movement and the more you rev, the more water circulates so i think the pump is ok...
Peter Nitschke wrote on Thursday, September 25, 2008 - 03:46 pm:
My experience is that even on really hot days, as long as the car is moving the big radiator cools quite well without needing the fan.
How are you establishing that the cooling is working well... I think that what i've proven is that the dash indicator isn't worth ••••••••
It reads 1/2 scale all the way from 88 degrees to 107 degrees...
I'm getting the radiator flushed just for piece of mind, even though it's going to be a pain in the arse to remove, but i'm starting to think that these motors might run hot normally?
Saturday, September 27, 2008 - 10:09 am, by: Damian Ware(Frozenpod)
Hi Tai,
Great info and research.
IMO the V8 do run quite hot from factory even with a perfect cooling system.
Yes the water temp gauge never moves but I have always felt the underboonet temps in the V8's and the V6 camry's are a lot hotter than other cars.
After a drive my TT engine bay would be warm but not super hot where as on the V8 it is super hot. If I was running the TT on boost that was a different story but at cruise speeds and traffic driving there is a huge difference in under bonnet temps.
Matt, cooling systems if maintained nearly never wear out.
After 340,000km my top tank died the the camry.
I removed the radiator core and was planning to flush it or replace it.
The core still looked like new.
I have been considering a TRD thermostat myself but I am unsure of the bennifit.
TRD thermostat is 71 deg C and regular is 82 deg C. With all the water temps you are measuring the thermostat once warm will be open all the way regardless of 71 or 82 deg type. Wouldn't you agree.
Certainly is worth testing how it effects the coolant temp.
As to the temp gauge not moving the radiator has a more than one temp sensor.
The temp gauge in the dash is different to what the ECU sees.
The are in very different locations so perhaps this has a large effect on the actual temp being measured.
Tai Johnsen DieHard QLD UZZ31 - Supercharged & Intercooled V8
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and a Supercharged Manual V8 
Then drive home. 
so that leaves the fan speed control issue or radiator... Or water pump? 
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