Engine cooling issue

[303Gunner]

Had some cooling issues rear their head today for the first time, wasn't a particularly hot day.

Started the car up, no funny noises, no puddles, etc. As the temp gauge crept up, it kept going past the 90-95deg point it normally sits at to settle in the black zone around 100-110deg. When pushed up a hill, it would just touch the red.

Popped the bonnet for a look see. Fan belt good and tight. Water pump turning, no sign of any leaks. Thermostat housing hot to touch. Upper rad hose hot. Radiator warm, but can easily keep my hand on it. Bottom rad hose cold. Condensor tank cold and not pressurised, when I remove the cap I have lots of coolant there.

Can squeeze the upper hose (with a rag, it's very hot), feels firm. Can squeeze bottom hose and hear coolant squishing through. Don't know if I'm pumping it back into the rad, or into the block via the pump. After doing this for a while, the hose warms up, so I think I'm pumping the coolant in and out of the block, because the rad's not that hot.

So, what do people think I should be looking at? My guess is a blocked radiator. Pull it out and hopefully find flakes of crud, shake em out all good. Worst case, take it to a radiator specialist to have it rodded out.

I don't think it's the thermostat, as the top bits are all hot. I don't think it's the water pump because there's no obvious signs there, but that doesn't mean there's not an internal issue with the pump (impeller  missing fins, fallen off the shaft?)

[Diana Alan]

Getting the radiator rodded with a newly acquired vehicle is usually a good idea.  Particularly with ex-Army vehicles as they used what ever water was available, even muddy creek water if needs be.

When I dismantled 49-353 there was no evidence of corrosion inhibiter or anti-boil additives, so I'm seriously considering rodding the radiator.  Unfortunately it may also mean a new core, looking at the condition of the fins.

My personal opinion is to avoid NatRad cores, and get something like Adrad Australian made replacement cores.  NatRad were once great but in recent times I've personally had reliability problems with them and my local repairer and long time Sydney institution J.J. Smith has recently been bought out by Natrad so I'm looking for an alternative. 

[BEARMAN]

Getting the radiator rodded with a newly acquired vehicle is usually a good idea.  Particularly with ex-Army vehicles as they used what ever water was available, even muddy creek water if needs be.

When I dismantled 49-353 there was no evidence of corrosion inhibiter or anti-boil additives, so I'm seriously considering rodding the radiator.  Unfortunately it may also mean a new core, looking at the condition of the fins.

My personal opinion is to avoid NatRad cores, and get something like Adrad Australian made replacement cores.  NatRad were once great but in recent times I've personally had reliability problems with them and my local repairer and long time Sydney institution J.J. Smith has recently been bought out by Natrad so I'm looking for an alternative. 

Sounds like thermostat to me gunner - not opening properly.

[Rangy35]

So how did you go with this? Sounds like a thermostat that is sticking to me too.

[BadCo.]

I pulled my radiator the other day to find brown liquid coming out of the bottom hose. Sent it in to get flushed and ended up with a new core. Wasn't happy about it but better to find out when its on axle stands at home rather then in the bush.

So, send the radiator in if you recently bought your Perentie!

[Sixty]

110's should have the alfloc/coolant flushed every coupla years or it turns to mud....some tradies are lazy or plain useless and it never gets done.

As a starter, I suggest flush the entire cooling system, and replace the thermostat & seal   

[dugite]

I'd have a tank taken off and have it rodded - not expensive

If you replace the thermostat make sure that you replace the "o" ring (isuzu part # 8-94176031-0)

Don't take the thermostat out without replacing the o-ring - you'll see why when you dismantle it.

[Carzee]

Just to be safe i have put a Perentie 110 4x4 radiator in for a recore. The logbook says the radiator was last replaced 12 years ago. Where we are headed an untrustworthy 12yo radiator is not good sense.

I saw that a local Natrad place was stacked with cartons of fresh cores of all shapes (all having the same chinese country of origin) so I sought out a local hot rod club recommended ADRAD radiator rebuilder, and fortunately Canberra does have one in Fyshwick.

Along the way I learnt some things.

Eg: The Perentie 4x4 core (correct sized) is in their catalogue and I was advised it would be $1300. BTW, that is considerably cheaper than the dealer sauced genuine radiator part. Apologies, but I didn't lookout for 6x6 info while I was there.

... but was there an alternative core they could fit between the tanks? My radiator core length and width was measured and the catalogues were checked.. yes, a ADRAD Rover car V8 radiator (part "ROV391") would fit the width and length with a little trim lengthways. Cost was $850 incl. tax. A choice of paint colour as well, as long as you choose black.

I did not fit the radiator in the Perentie as yet. I will fit the radiator when the grille panel is removed. The panel has to be trimmed to clear the winch when I fit it.