GU Patrol 4.2td Where does your temp gage sit when towwing

Same with mine! 03 4.2 tdi

Yes Genuine

Same here, just done 6500K with Jayco Swan Outback (1150kg Tare, fully loaded 13-1400?) Car new only had 2300k on it when we started. Gauge never moved. We went through Ayers Rock, Kings Canyon, Alice, Oodnadatta Track etc. No issues.

PS rarely use 5th gear even at 120kph when loaded and I have still gone through the hassle of having to rebuild my gearbox with a near stuffed 5th gear and mainshaft.

Trevor.

Trevor

Do you lose your air-con now wen your temp gage is over 1/2 way with the new synser ?

Thanks

BBB

As said earlier, do a search on 4.2 overheating and see what comes up. That is actually how I found out about ExplorOz in the 1st place.......several years ago I googled that and it lead me here. They haven't been able to get rid of me ever since.

As far as the air-con cut-off is concerned, I've actually disabled that cut-off switch. This is simple to do, just unplug the cable joiner on the passenger's side bottom radiator tank. The swicth is in the bottom of the tank and has a short length of cable leading to a plug. Separate the 2 halves of the plug and no more air-con cut-out.

HOWEVER............. be aware that I have done a helluva-lot of work on my 4.2 Patrol to try to minimise the over-warming and also installed gauges to measure various temperatures.........water (in top radiator hose), oil (in sump) and exhaust gases (in both manifold AND dump pipe). So, at any given time, I can know exactly what temps my donk is being subjected to. Like Trevor said, you don't need to worry until the Nissan's gauge (horribly inaccurate once you fit a separate "proper" gauge) gets up to the extreme right-hand side "danger zone". Mine has never crossed over that final line into the danger zone. The highest actual temp I have noticed on the VDO gauge is around 118oC.

Cheers

Roachie

BBB,

Aircon rarely cuts out at all now with new sensor. The Nissan gauge needs to be right up the top right side of gauge (end of solid line) before the aircon cuts out. As Roachie has indicated this is about 118c on my VDO gauge also.

Roachie,

That's how I found this site too!! Bloody Nissans, see what they do, buy a car and get hooked on the net!!! Before this car I never used a computer.

Regards, Trevor.

Just unplug the sensor, but if temp goes to high u got a problem.

What diff ratio you running?
My revs are similar to BBB's.

I used to think the same thing too. My 2000 GU had a standard water-cooled turbo and I thought that it might be contributing to the heat issue. That was part of the reason I decided to do a Denco turbo upgrade. This involved replacing the Nissan turbo with a Schwitzer "dry" turbo about 1.5 times the size of the original turbo. The engine develops more power now and the boost has been cranked up to max of 15psi. However, the water temp issue hasn't really changed very much, so I've had to concede that the water-cooling of the old turbo didn't have a lot to do with the issue.

The TDi6 has a deeper radiator than the earlier models and maybe this has been a contributing factor, as I have yet to read of a TDi6 owner reporting any movement in the temp gauge. I fitted a huge PWR alloy radiator a couple of years ago and this didn't seem to help much either, although in fitting it I had to remove most of the shroud so I probably defeated the purpose to a large extent.

Hi Roachie et al,

When the TD6 (TD42Ti engine) came out, as well as the addition of the interooler, Nissan changed from a water-cooled turbo to an oil-cooled one and fitted the larger radiator from the 4.8 Petrol engine.

Not sure about the argument about water-coooled turbos adding to the cooling load. The water/oil-cooled bit refers to the coolng of the turbo bearing housing. Now for similar sized and loaded turbos, it seems to me you have the same amount of heat to get out of the bearing housing. So whether it's taken away by a conbination of water flow and oil flow, or just oil flow alone, the heat still ends up in the engine cooling system (either directly via the water flow or via the engine oil cooler).

By the way, Mr Roachie, I've been meaning to ask you for ages: What's the maximum difference between upstream and downstream EGT you've measured n yor hot(?) Nissan? [15psig boost - that's cookin' for a 4.2, isn't it]? I've measured almost 190C on my Land Rover 300Tdi (1.0 bar (~15psig) boost as standard) when working hard.

Re. your PWR radiator - thought of having a new shroud made up to suit? An unshrouded fan is far less efficient than one in a well-designed shroud.

G'day Ian,
You've raised a couple of interesting points........
1) The maximum difference between the 2 thermo-couples has been around 130oC

2) I take your point about the turbo heat needing to be funnelled to "somewhere". I guess my point is that the water cooling system seems to struggle and any reduction on the demands asked of it are to be welcomed. The oil cooling system on the other hand, seems to cope very well; it has only been under the most adverse conditions that I have seen the oil temp go above 90oC.

3) I agree with you that the lack of a shroud is less than ideal. I have countered this situation to a certain extent by fitting a front-mounted 14" Davies Craig fan (which I can switch on/off whenever I want to) and I have also unplugged the Nissan standard air con condenser fan (also in front of the radiator) and have rewired it parrallel with the Davies Craig unit. As a consequence, I have 2 large electric fans pushing air through from the front as well as the (less effecient due to no shroud) inner fan doing 'some' work. I have thought of possibly removing the inner fan altogether and fitting a pair of thermo fans from (say) an AU Falcon. These have their own integrated shroud and the overall size is reasonably close to the GU's radiator size.

Ian,

I knew there was one point you raised which I forgot to cover!!!!! (old age setting in).........

The maximum boost of 15psi is rarely utilised by me........and when I do, it is only for short periods of time (eg: hard acceleration during an overtaking manouvre).

I am a great advocate of fitting sensors and gauges (as you well-know!!!!!! lololol) and the boost gauge was a necessity as far as I am concerned, once I started moving away from a standard set-up. Indeed, all the gauges I have are 'needed' in my eyes. I now feel uncomfortable when I drive a vehicle which doesn't have all these gauges.....you're sort of left wondering "what's going on under the bonnet?" and keeping fingers crossed that you haven't lost a radiator/heater hose, fan belt etc.

Gmouse,

sorry mate but my best advise would be to save your dollars, relax when it's hot and drive a bit slower. Even with all the mods on mine (and a few other blokes on here) when the going gets hot, so does my Nissan no way to avoid it other than slow down IMO. I tried to work out as a percentage how often this is and it worked out negligible so that's why I have just thrown my hands in the air and said too hard basket, for the comparatively small amount of time I will just drive a bit slower (and when it's possible....hook right in to make up lost time LOL!!!).

Regards, Trevor.

This topic is really interesting and keeps popping up. I've been thinking (dangerous I know). People are putting in bigger radiators etc and not really solving the problem. The basics of heating and cooling is heat transfer, so if the waterways throughout the engine block, heads, manifolds etc aren't big enough to allow the water to flow through and remove the heat it doesn't matter what size radiator or water pump you have, the engine is still going to overheat. There is obviously a relationship between the speed of the water through the engine block and the amount of heat it can remove in a given time.

Could be bunckum but maybe another angle?

Exactly!!!!

Like Trevor says, save your bucks. My huge PWR radiator cost $1100- 2 years ago and was, in hindsight, a waste of money. It's a great radiator, but like Grizzle says, if the water galleries are too small for the mass of the block, all the cooling in the world won't help.

Gmouse, you say your Patrol got warm on a really hot day. As has been said before, you don't need to worry until the needle goes right over into the last bit of it's travel. In deed, I reckon it's good to see the gauge displaying some change as the temp goes up. The blokes who say their gauge never moves no matter how hot the ambient is or how hard they push their vehicle, are kidding themselves if they think their engine's coolant is staying at exactly the same temp all the time. There are large variations in water temp in all vehicles, it's just that the factory gauges are designed to sit in one spot 99% of the time so as not to 'worry' the driver with fluctuations.

As Trevor has said above, you could replace the switch in the bottom of the radiator with the newer model (I didn't know about this until I read it a few minutes ago).....or, you could simply disconnect it like I have (but then need to keep an eye on the temp gauge and be prepared to switch the air con off if the temp gauge goes ballistic.

One other thing I haven't mentioned in this thread before is that the integrity of the cooling system can be checked by taking note of how quickly the temp gauge reverts back to the "normal" position once the difficult condition (eg: climbing the long hill etc) has passed. In my case, within 30 seconds of cresting a long hill and with the temp having peaked at say 115oC, the temp reduces back to under 105oC (at which point the Nissan gauge is back to the 'normal' position). The Nissan gauge sits on the 'normal' position during fluctations of the water temp (as measured by the VDO gauge sender in the top hose) from 55oC to 105oC.

Thanks for your input much appreciated, so sounds like it’s not just me then
now I’m thinking about de pressurising the radiator this I did on a 351 XY
many years ago and had good success

But only in the hotter weather and back on with the old rad cap as the cooler months came by

Again, many thanks

Cheers

Yeah Gmouse, that is something Nissan had thought of and there is another cap out there. If you have not got the 1.1 cap (I think .9 was the old one??) then that is an off the shelf item at Nissan. There is also a lower temp thermostat but I don't think this did much but it is info for you if you want it.

Cheers, Trevor.