2007 GU Running Hot

[andrewh]

Hi

Would be interested in some opinions please

Just picked up a 2007 GU on the weekend and drove it back to Perth from Busselton with no dramas.

Took it out to work today with a trailer on the back (about a tonne) and in the middle of the day (37 deg) it got real hot real quick - it shut off the air con and I had to drive real easy to get home.

The radiator cap was stuffed so I replaced that, but it obviously wasn't the source of the problem.

It stays cool at idle (thermo is working and seems to be ok) but gets hot under load.

I am guessing these are classic symptoms of a blocked radiator? The coolant looked fresh and it wasn't losing any. It didn't 'boil' as I backed off before it got serious.

I'm new to GUs so would be interested to hear some wisdom from those who have had similar problems

Cheers

[MEGOMONSTER]

There are plenty of threads regarding this problem, use the search bar to find them.
By the sounds of it you may have "Goats Syndrome" where the mixture of two different coolants has created a glug type substance in the radiator and blocking some fins.

[threedogs]

Cooling systems aren't complex. radiator, thermostat and waterpump.
Is power still good??only use OE thermostat.
07 what ???? diesel or Petrol ????
Find Goats thread on over heating 2010

[gaddy]

Gidday giveit a good external clean as well inbetween the fins as well

Gaddy

[Morton]

it will be your radiator or cap or thermostat aided by a dirty MAF sensor & air filter, first have your cooling system tested for leaks & check for obvious leaks etc, if it is a 3L it is a bit of a pig to get to the thermostat as it is in the bottom right corner looking at the vehicle, pull the radiator out first, look for blocked fins externally, pretty common, clean it out thoroughly inside & out, back flush the engine & radiator & look at what comes out of both, a gluggy solution will indicate goat syndrome, also known as d^^k cheese in some circles, this is a bit of an issue many dont look for, fit a genuine cap, genuine thermostat & genuine air filter, fit new coolant at 33% ratio, then clean your MAF sensor & Bobs your relative, for a 3L this should be all that is required

[threedogs]

Good advice Morton, Goat syndrome love it, shite the dramas that guy had,
Anyway was just at a radiator shop for intercooler info and mentioned your
problem. Seems the GU radiator is reknowned for glogging especially if coolants have
been mixed, going away this weekend with Bob will let you know if he's relo material,lol
sure he is. settle Bob

[andrewh]

Thanks folks - will get it looked at on Friday - it's been a long hot week

[Lieney]

Check nothing is blocking air flow through your radiator. Fins straight and clean etc. Do you have a front mount?
Have you just fitted a massive set of Lightforce spotties that block the air flow?
If you were to hose the radiator out that contains bugs and debris, be very careful as they can swell causing minor cracking and damage to radiator. Or they jam in.
Ensure your radiator cap operates properly - pressurises and releases at correct pressure
Ensure your water pump intake hose is not 'sucking' closed when hot and running high rpm
Ensure you have the correct mix of coolant - prevent thickening. Also if the coolant is the wrong mix, it can boil prematurely and cause cavitation and air bubbles in and around internal engine components, thus reducing the efficiency of the system
Ensure radiator internals are clear
Ensure thermostat is functioning correctly
Ensure water pump operating effectively
Towing heavy trailer will cause it to get hotter. Boost will be up, EGTs will be up, fuel consumption will be up.
Might have to back the throttle off, or get a bigger radiator

[NP99]

I'd check thermostat.

[andrewh]

Hi Lieny

Yeah - I get that towing a trailer on a hot day does up the pressure on the rad. I did think these things were made for a bit of hard work.

I'm thinking they will find it on Friday - hopefully - maybe as simple as the thermostat...

That'd be nice :)

[andrewh]

So it seems it was a 40% blockage in the radiator...

They didn't comment on how it happened but it seems to be running sweet now

[MEGOMONSTER]

So it seems it was a 40% blockage in the radiator...

They didn't comment on how it happened but it seems to be running sweet now

That'll do it, good to see all sweet.

[Morton]

coolant mixed or colant mix is wrong, eitherway a good result