Is the Doctor in – Engine Temperature?

[Johan B]

Not sure whether this belongs in the Electrical or Engine section but here goes.

Went up to Marakele with the trailer on our first trip (Camp master wilderness and Echo tent and kitchen). At +/- 100 kph the vehicle temperature is fine but as soon as you go above this the Trol (’99 4.2 D) heats up so the dial is just to the right of the middle of the temperature gauge, where as at 100kph it is just to the left of the middle.

Now for the funny thing, if the temperature is low the aircon works fine but as soon as the vehicle heats up the aircon still blows air but not cold air as soon as the temprature returns to “normal the aircon works again…???

What can cause this sudden shift in temperature, is this normal and why does the aircon stop working at this stage?

Without the trailer the temperature is fine and the aircon keeps us cool even at 130 kph.

[Abri Hoffman]

Can't tell you why the vehicle heat up. On the aircon though, its got a safety feature that will disengage the aircon above a certain temp. Very frustrating but intended to save the engine by reducing load.

[raka]

http://www.nissan4x4.co.za/forum/forum_ ... 3370#33370
Johan B, gaan lees hier en die verwysing na die ausie forum.
Bytheway het jy n turbo op ?

[Johan B]

Geen turbo nie.

Die voertuig is fabriek std behalwe vir Old Man Emu shocks.

Dit het nog die oorspronklike Nissan Radio/Type ook in.

[Ross]

Hi Johan,

This sounds similar to an issue that Wes (SRXy on this forum) picked up on his 4.2 when heavily laden with RTT and 33" M/T`s on our trip to Botswana and Zambia earlier this year.

The issue only seemed to arise of hot days, when running above 100km/h with some gradient involved. The solution during the trip was just to take things a bit easy, and not use aircon, and this kept the temp in the middle of the gauge. After our return Wes thoroughly flushed the cooling system on his van, and I think also replaced the thermostat. Since doing this the problem has not re-occurred, although I don`t think the van has been loaded to the extent it was for the trip since these measures were taken.

So, possibly a cooling system flush may be worth while if you havn`t done one recently (should be done once a year preferably).

Not sure whether a faulty viscous fan could account for the problem, but it may be worth checking that it is engaging properly when the engine gets up to temp.

Hope that helps. Good Luck!

Cheers,

Ross

[Mayhem]

Hi John, I am almost sure it is your viscus coupling on the fan,I had the same problem and after all the things that I did it was the viscous coupling that was at fault. good luck

[ChristoSlang]

Johan, my 'Trol is behaving the same way...

We returned from Mozambique a few weeks back: 4x grownups, Patrol fully loaded with all manner of camping kit inside and our tents & camping chairs on the roofrack. Between Pongola & Piet Retief the outside temperature rose to about 35 deg. C and the aircon also turned off as we tackled the hills. The engine temperature climbed all the way to the very end of the "Normal" area, with the Madman EMS reporting that the coolant temperature was at 118 deg. C. But it remianed there, never entered the red area and no coolant was lost from the expansion tank. The EGT did not go over 580 deg. C either.

I recently replaced the thermostat, and flushed the radiator out a few months ago. The intercooler also has a fan that's managed by the EMS system to improve airflow when the engine reaches a preset temperature. Timing and fueling should also be OK - the truck was dyno tuned recently when the injector tips were replaced and I do not have black smoke (indicative of over-fuelling) under load. As far as I know my vehicle also has an uprated radiator (have never had the opportunity to compare it with another 4.2).

So, the Bruces & Sheilas from our sister forum may just be right when they say this is normal behaviour for the 4.2 Patrol motor

[Johan B]

Sunday was quite hot in the North.

The temperature returns to normal quite quickly when reducing the speed, with in a few minutes I’d say.

After reading the review on the Nissan4x4 site and the Ausie site I came to the same conclusion that the cooling system on the 4.2’s is not quite adequate enough to handle a very hot day.

I will check the fan coupling and flush the system.

So the best thing is to just relax, drop the speed, open the windows and enjoy the ride.

The fuel consumption on this trip was 7km/pl with 314 000km on the clock.

Just imagine what Nissan would have charged me for this amount of advice and support?

Thank you to everybody that helped.

[Pieter du Toit]

Johan,

Also speak to Frans Fourie (Tour de Frans on the forum) he also has a '99 4.2D which he also turbo'ed. Had similar problems and had a new and bigger radiator and also single core (VERY IMPORTANT) built for him self - and if I remember correctly he said it was not even a majorly expensive excersize. I have seen his radiator - ITS MASSIVE!!!

That was the end of his problems. Hope you come right.

[tour de frans]

Hallo Johan,
4.2s turbo or not run hot,atleast mine did before the turbo and after.I built a bigger radiator and supported the radiator hoses with s/steel wire.I found on the dyno at high rpm the bottom hose sucks close,therefore no flow.
Read my post in "hot air through vents" about how the ac work,and cooling.
To much or wrong antifreeze will help overheating.Thermostat,viscous,fancowl check them and is'nt the fan the wrong way arround on the viscous?
hope you come right.
Rdgs
Frans