Outer Limits 4x4 Board

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

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

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.

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

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

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

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

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

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.

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.

timing advanced?

that will also make it run hot.

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?

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

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)

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?

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.

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

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.