GQ RUNS HOT

Joined: 08 Jul 2008 Location: vic

hey all
I have a gq wagon 4.2 diesel that runs hot when towing 3/4 plus on gauge when towing up hill
runs 1/2 any other time
has had head recond as mechanic said that was it(it wasnt $ 2000 later)
new hd radiator
new nissan thermostat
block flushed
new hoses
ANY IDEAS ?
Im close to pushing it off a cliff
cheers andrew

Joined: 30 Jan 2003 Location: New Zealand

Have you checked the fan is working correctly? Might need stripping and have the silicon replaced inside it

Joined: 13 Jan 2004 Location: Canberra

KIWI wrote:

Have you checked the fan is working correctly? Might need stripping and have the silicon replaced inside it

Also water pump vanes can be worn & not circulating the water enough.

Also, how much smoke is it blowing, more fuel = heat in a diesel.

Joined: 20 May 2005 Location: maitland

mine use to do this when towing a boat no big deal just ease off a bit on the flat so she cools down abit, they are tough motors and australia can be a hot place

Joined: 08 Jul 2008 Location: vic

yeah i forgot it has a new water pump too
might check fan though

Posted: Sun Aug 31, 2008 2:06 pm

chinese rad or a good one?
few people have had issues with the chinese ones...

Joined: 08 Jul 2008 Location: vic

started by getting to stock one cleaned by a mate that owns a rad shop
he said it was in great nick (thought I better with new head)
then bought a 3 core (brand unknown thought mate at rad shop)
no change cost me $400 cussing

Posted: Sun Aug 31, 2008 7:32 pm

well if it made no change can prob rule it out.

its strange with these overheating issues, have you tried replacing the sender unit to the temp gauge?
i wonder if sometimes they start to play up.
on my GQ TD42 the needle never goes above 1/3 unless a hot day, and under constand hills at 3000RPM it will reach nearly halfway...

maybe buy a cheap coolant temp gauge and see how the temps are actually going? might not be a real issue there to deal with

Joined: 02 Mar 2008 Location: Mackay Qld

Have you got a pyro temp gauge? That will give you a better indication of how hot the engines getting and wether your going to damge it.

Joined: 16 Oct 2007 Location: Brisbane

Tomo_89 wrote:

Have you got a pyro temp gauge? That will give you a better indication of how hot the engines getting and wether your going to damge it.

that won't really tell you if the engine is overheating or not.

Posted: Mon Sep 01, 2008 4:04 am

timing advanced?

that will also make it run hot.

Joined: 22 Jun 2003 Location: Location: Location: Location:

3/4's isn't overheating.
Check the tune of the car and injectors.

Is it turbo'd?
Do you have the shroud still on including the bottom clip?
Have you done a body lift?

Joined: 08 Jul 2008 Location: vic

hey johnno
no lift
injectors done maybe 35000kn ago
full shroud
motor in good knick
Getting ready to have a small engine fire if I cant fix It Twisted Evil

Joined: 22 Jun 2003 Location: Location: Location: Location:

Once again 3/4's isn't over heating.
Anything up to just below the line is still safe.

But I know where you're coming from, it's very stressful.

Is yours an auto?
Does the auto get cooled from the end tanks of the radiator? This can transfer heat into the radiator. I bypassed these end tanks and added 2 separate oil coolers in front of the condenser.

I have also replaced my radiator with a larger aluminium unit from Aussie Desert Coolers as the original didn't have the capacity to cool it. (Mine is turbo'd which can place extra strain on the system)

Joined: 14 Jan 2007 Location: Melbourne

GUJohnno wrote:

I have also replaced my radiator with a larger aluminium unit from Aussie Desert Coolers as the original didn't have the capacity to cool it. (Mine is turbo'd which can place extra strain on the system)

Do Aussie Desert Coolers have a stock radiator for the GQ or did you have to get one custom made? If not a rude question how much for the radiator?

Joined: 12 Sep 2007 Location: sunny coast

my gq has nearly been the death of me with the overheating. fine until you need to tow uphill or give it a good flogging.

i have had fan repacked, blades replaced, head checked, shroud replaced put a aussie desert cooler 3 core triple flow aluminium rad,new water pump,hose,full system flushed, 3 aftermarket thermostats with no to 12 small holes drilled through them to check water flow rates and still got hot towing a trailer with a lada on it up to cruiser.ordered a gen thermostat to try now.

the gauges are all over the place my factory guage got to just below the top line on the gauge but my 2 aux gauges (one elec one old school as not sure which one to trust) got up to 120 and 125 degrees but nowhere to pull over so had to carry on at turtle speed. cools down within minutes of no load though. motor is a 4.2 td gq with a gu 1 pump and turbo blows a tiny bit of smoke so not overfuelled done on dyno with a front mount. even cleaned out intercooler and rad before we left.

gettin to the point of no return soon, should have just bought a gu motor and shoved that in would have been cheaper. had a guy have the same prob and he shoved chemiweld in it and rekoned that fixed it.

check you rad though as the china one have bigger gaps between the fins and are not for turbos or towing. i had one of those. fine until you wanted to do 100km/h then got hot.

good luck and let us know how you go.

Joined: 22 Jun 2003 Location: Location: Location: Location:

T_Diesel wrote:

GUJohnno wrote:

I have also replaced my radiator with a larger aluminium unit from Aussie Desert Coolers as the original didn't have the capacity to cool it. (Mine is turbo'd which can place extra strain on the system)

Do Aussie Desert Coolers have a stock radiator for the GQ or did you have to get one custom made? If not a rude question how much for the radiator?

Yes they have in stock brass and aluminium radiators.
The guy said the aluminium was slightly more efficient than the brass units so I got one of those. Check on the price, I think it was around the $830.00 mark

Joined: 24 Jun 2007 Location: Bundy QLD

Nissan gauges are very sensitive so 3/4 may only be 92 degrees, as I found out with after market computer temp screen on tb42 turbo winch challenge truck! When the needle is almost at red, 102 degrees, so check that first. I have and exhaust temp on my GUII td42 turbo and I back off when it gets to 600 degrees. The aircond cutouts at 3/4 water temp, great idea nissan, but if you watch the exhaust temp will never happen.

PURK.