check your radiators

[purplebus]

just a quik note to let you know to check your new rads. Purchased a 3 core triple bypass rad off a reputable australian company for a td42t approx 2 yrs ago. rad made no difference to running temps etc and cost me plenty $$$$$. Was going to use it for new project and had the inlet /outlet ports cut off to swap sides and found out it is only a 2 core with no bypasses... .

have emailed the company to see what they say and if they will just exchange it for what I ordered and payed for as accidents can happen . big difference in prices between what I ordered and what I recieved.

[gqswb]

Doesn't surprise me, A few weeks ago I ordered a aluminium rad from Adelaide for a petrol GQ, only to get a Diesel one in the petrol box.. At least in the end I did get what I paid for and it made a huge difference to the temp. Good luck with yours.

[Canyonero 4x4]

While on the topic of radiators, avoid using the flexible multi-fit hoses with the wire coil in them.
I bought a hilux that had one of these on, no idea how old it was but the coil corroded, fell to bits and ended up like a birdnest of wire in the hose, blocked flow through to the themostat, it overheated and killed the motor. I found little bits of this wire all through the cooling system.

[gingerbreadman]

another tip with alloy radiators...before you install one do a electrolysis test.

[nerida67]

Another tip with the GQ petty radiators is make sure they have allowances for the bottom sensor (drivers side)
The new rad i bought for the GQ 9 months ago didnt have this and had to be modded to accept

[gqswb]

Another tip with the GQ petty radiators is make sure they have allowances for the bottom sensor (drivers side)
The new rad i bought for the GQ 9 months ago didnt have this and had to be modded to accept

hmm..
I just bought new rad without the thread for the sensor and old temp sensor is still sitting in my old radiator. My temp gauge is working no problems.. but how I wonder..

[purplebus]

Another tip with the GQ petty radiators is make sure they have allowances for the bottom sensor (drivers side)
The new rad i bought for the GQ 9 months ago didnt have this and had to be modded to accept

hmm..
I just bought new rad without the thread for the sensor and old temp sensor is still sitting in my old radiator. My temp gauge is working no problems.. but how I wonder..

the diesels have the temp sender in the thermostat housing area. I dont know what the sensors in the rad are for, not all have them. maybe cold start sensor for an auto..???

[gqswb]

Just got home and checked the service manual. That sensor on the bottom radiator hose outlet is the over-temp cut out for the air con. I pulled my A/C out when the turbo/front mount went in so no loss to me.

[rowenb]

another tip with alloy radiators...before you install one do a electrolysis test.

How do you do an electrolysis test? Use your eyes or is there a proper meathod?

[purplebus]

Just got home and checked the service manual. That sensor on the bottom radiator hose outlet is the over-temp cut out for the air con. I pulled my A/C out when the turbo/front mount went in so no loss to me.

thanks for that. wondered what it was for.

[gqswb]

another tip with alloy radiators...before you install one do a electrolysis test.

How do you do an electrolysis test? Use your eyes or is there a proper meathod?

Use a multimeter on its lowest DC range. Connect the negative lead on the meter to the negative on the battery and the stick the meters positive lead into the coolant that you should be able to see in the radiator filler neck, if the water is a bit low top it up till you can see/poke into the water WITHOUT the lead touching the metal radiator.

You are looking for a DC voltage under 50 mV (The max limit with out being critical), The lower the better and try with and with out the ignition switched on.

If you do find some stray current don't earth the radiator as that completes a electrical circuit passing current thru your radiator. Find the problem which could be anywhere... Lights, accessories, etc..


That's how I did it after some research on testing for stray current - It wasn't till the night that it was fitted that i researched solving it..
After my system was flushed and new radiator was fitted and corrosion inhibitor added I tested for stray currents and found ~200 mV I was almost freaking out! and earthed the radiator with no effect.
That night doing some research I read that adding new coolant / corrosion inhibitor could create some voltage and you should test again after 12-24 hours. Also read about NOT earthing the radiator. Next morning removed earth, tested voltage and it was way under 50 mV (cant remember exactly what) - should test it again (curious).

[nerida67]

Yeah thanks for the REAL reason what this bottom sensor is for
When i got the rad i wasnt sure what it was for so would ya beleive i rang nissan and asked
And the wombats there didnt know ,and just said youll be right just leave it off

[gingerbreadman]

another tip with alloy radiators...before you install one do a electrolysis test.

How do you do an electrolysis test? Use your eyes or is there a proper meathod?

yes gqswb pretty much summed it up.make sure you do the part where he said touch the coolant onbly and not the filler neck. i only have an alloy radiator in one of my cars and wont go in that direction again. all my cars with copper/brass radiators have the potential to cool to 160 f if i choose that thermostat so my question is ...are alloy really worth it? and my answer is no. once they leak they are hard to repair, expensive and generally have a shorter life .

copper/ brass rads still suffer from electrolysis but are way less fragile to it than alloy.

its a good idea to test with tap water only and on each test refill with new water as a positive charge can remain in water even without the engine running. once you get your reading down to less than .05 of a volt like gqswb mentioned then fill with coolant and DEMINERALISED water.

i use sacrificial anodes, 60/40 mix of red holden coolant which is glycol and also electrolysis arrestor just to be sure.