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Rad is about to burst.

Posted: Sun Nov 30, 2014 5:23 pm
by mac_stang
As the title says, it appears our rad is about burst. Noticed a drip, got under it and noticed the sides of the rad are swelling outwards...new rad about 45k ago, warms up in the same time as always and the gauge site as per usual, and in the summer the temp started to climb on the Coq(gauge reflected this and seems to work). I will change out the rad and thermostat if I can source them. I have never seen this in the 22 vehicles I've had the pleasure of calling my own, any ideas? Rad cap seems to be ok...


Brad.

Re: Rad is about to burst.

Posted: Mon Dec 01, 2014 5:18 am
by Big-Bird
There are 2 things that can cause that. Poor quality radiator or too hot of a thermostat (with the possibility of a faulty radiator cap).

Mardy from amazing auto posted a thread this year warning us about using a thermostat with a higher temp range....one thats actually meant for the Pajero. The Pajero is a little heavier than its Delica Cousin and has a bigger radiator which allows it to run slightly hotter. A bigger rad can handle the extra heat load.

Check the rad cap for actual pressure releif operation....Partsource has a radiator pressure tester and it should have an adapter to test various rad caps.....you can also get your local oil change shop to test it.

Re: Rad is about to burst.

Posted: Tue Dec 02, 2014 7:29 pm
by mac_stang
Changed out the thermostat and the rad today, thermo definitely looked beat up. Everything else looked absolutely fine, fluid was good to -40, and all hoses looked good(changed out both rad hoses anyhow)

Brad.

Re: Rad is about to burst.

Posted: Wed Dec 03, 2014 5:23 am
by Big-Bird
Was the thermo faulty? They are designed to fail in the open position, rare for.them to fail in closed or even semi closed.

Its also further strange that the rad cap didn't relieve the excess pressure and instead the rad swelled.

I have the normal problem, thermo is stuck open...engine won't stay hot at idle. Changing thermo this weekend. Gonna do the boil test on the old one as well.