Is the Doctor in – Engine Temperature?

[Gerrit Loubser]

I don't think the viscous coupling on the cooling fan would be the culprit if the overheating occurs at speeds of 100 km/h or more. At this speed I would think that the forward motion of the vehicle is responsible for airflow through the radiator and not the fan.

By the way, I had a similar experience on Sunday with my 4.5E GRX while towing my heavily laden Conqueror Conquest trailer through deep sand in 37 deg C ambient conditions.

The going was slow (low range, 2nd, sometimes 3rd briefly) and hard and I would notice the temp needle rising until it was slightly to the hot side of normal (still far from the red), at which point the aircon would cut out. The temp would immediately start to drop down until the needle settled a little below the mid position and then the aircon came on again. This cycle repeated itself over and over, but the temp never got out of hand (at least not on the gauge).

I am not sure whether this is normal behaviour for the TB45E equipped Patrol or if I need to dig into the cooling system on mine. I would start with the thermostat.

[Gerrit Loubser]

Oh and the moment we were out of the deep sand, the temperature gauge needle remained in the middle and the aircon worked constantly at all speeds, while towing the same trailer in the same ambient temperature.

[tour de frans]

Gerrit,that is normal,read my post in"hot air through vent",how the AC work with the radiator.
Rdgs

[Gerrit Loubser]

Thanks, Frans. Yes, I understand the functioning of the protection system that cuts the air conditioner when the engine temp exceeds a limit, but does it sound right that system was activated in the conditions described?

[tour de frans]

Yes Gerrit,the system wil cut the AC before it is to hot.If you work your car like you did and hot outside, and the AC being cut,the water temp is stil fine.The system cut it early so it prevent overheating ones it is realy hot,iow if the system cut the AC when the heatguage is over half,it might to late to cool fast again.Car stil not overheating.
Rdgs

[Gerrit Loubser]

Thanks a lot, Frans .

[Johan B]

Hi Guys

Here are some feedback:
I experienced the same heating and returning to normal cycle, but the cooling was not enough to have the aircon engage again. This meant the “airkom by die venster in”. I thought this was normal but after a work college told me a friend with the same Troll did not notice any heat increase on his Troll I decided to clean the cooling system.

So I took out the radiator and delivered it to Silverton Radiators in Centurion with the instructions “please service, clean and repair”. Picked it up 24 hours later looking brand new and cleaned. Went to Nissan in Centurion armed with the VIN number and 24 hours later I had two new radiator hoses and 3 litres of coolant.

Fitted the radiator, cleaned the aircon radiator and flushed the reservoir on Saturday morning and hit the road Saturday afternoon and Sunday morning, riding every hill and mountain from Roodepoort to Hartbees port dam. Normally I would have the heating problem as soon as I hit the road back from Harties but could not get the gauge to go above normal or the aircon to stop working.

The cleaning of the radiator and the coolant was R350 and R330 respectively, the pipes though were R1200 (from Nissan, could not get them anywhere else).
Will keep an eye on this but ,this seems to have done the trick. The viscous fan is working properly.

[JG Shields]

Johan,

Although I discussed the exact similar symptoms on my 4.8 on another post, I can confirm that I had the same finding.I had similar symptoms with my 4.8, especially with ambient temp above 33 degr and under hard working conditions. The Viscous kicked in very soon and I was always well aware of its noisy existance. I replaced my old radiator with a new one last week, since my old radiator was suspect for many reasons. I took the time and tested the car to its limits this weekend in the Waterberg area. In the most difficult of conditions, I hardly notce the Viscous kicing in at all. Although I do not measure the exact temp with an additional instrument, I have a good feeling for what is happening and I am convinced that my car runs much-much cooler. The old radiator was halfway blocked with dirt on the outside, however I suspect the real blockage to be on the inside. This simple aspect is often neglected by ourselves as well as the service agents. The Patrols are all high engine capacity vehicles which generate a lot of heat. Other than a normal "plaas bakkie", I believe that we need to take special care of the Patrol's cooling system.

[4drlouis]

I see Ross mentioned the same experience, and then mentioned the size of his tires. I've also noticed recently that my 96 4.2 SGL runs at higher temperatures than I'm used to. This began after I put some bigger rubber on the car (also 33' Bighorns). Would the the tire size really make such a big difference? Frans also mentioned the the fan might be going the wrong direction. How do you change the direction of the fan? I had all the fan belts replaced recently. How would I know the fan is going the wrong way? As far as I have it, the viscous coupling engages as the engine becomes hotter. My fan is turning from the time I start the motor. I cannot see a difference in the fan speed when the car is cold, or when it is hot. Some insight would be much appreciated, thanks.

Blessings

Louis

[Pieter du Toit]

JG,

Jou nuwe radiator wat jy ingesit het - kon jy dit slegs by die agente kry en as jy nie omgee ek vra nie wat het dit jou gekos?? Jy gebruik ook mos nog jou 3.0L se standaard radiator ne.

Mufasa het nou 150 000km op die klok - ek het nog nooit die radiator skoon gemaak in die 3 jaar wat ek my patrol besit nie - en ek dink ook nie die vorige eienaar het regtig iets gedoen nie. Die radiator is wel geflush met die 4.2 conversion en die pressure en overflow tenke skoon gemaak. Ek moet eerlik waar vir jou se die water in my stelsel is mooi skoon - geen ergelike bruin of modderige kleur nie. As ek my radiator prop afdraai dan kan ek deur die water sien en dis n duidelike groen kleur van die anti-freeze. Selfs die overflow en pressure tenke se water is mooi skoon. Kan dit beteken dat my radiator "goed" is?? (Want ek het mos nou ook die warm word probleempie) En dan het ek mos nou ook gespring van die standaard 265/70/16 tyres na die 305/75/16 - indien dit wel n invloed het.

Ons kon nog nie by die insit van my olie cooler uitkom nie - maar dit gaan ek beslis ook nog insit. Volgens die eienaar van Bosch Auto Services wat Mufasa diens se indien ek slegs n warm word probleem ondervind teen opdraande swaar gelaai en trailer in tou dan beteken dit die kar se water kapasiteit is nie genoeg nie - hy se dis dieselfde beginsel as wat jy twee koppies water kook of n hele ketel water kook - die twee koppies water gaan baie vinniger kook as die hele ketel.

Hierdie warm word probleem dryf my en Frans na raserny want ek wil dit nie he nie - ek hou nie daarvan nie. My water temperatuur op my EMS monitor het al verby die 120 grade merk gegaan maar die patrol se eie hitte gauge het nog nooit naby die rooi gekom nie maar wel oppad na die 3/4 merk toe gestyg. My enigste "concern" om my radiator te verander of vervang is jy het nou petrol kar en ek nog steeds diesel - en dit wil my voorkom of die diesels maar bly warm loop - ongeag of die radiator skoon gemaak is.

Sal jou insette wardeer.

Groete