Pajero Owners Club of South Africa

Hi guys,

I would like to add another possible cause for the overheating:
Check that the sealing gasket between the radiator and the bodywork is in good condition. If it is not, then there is the possibility of hot air recirculating from the rear of the rad (after it has done it's job of collecting heat) and via the damaged gasket to the front of the rad and back thru the rad. Being hot, it's ability to draw heat from the rad will be greatly reduced.

I have experienced this on my Pajero.

Cloyd

Hi
I have also been experiencing the problem of overheating on hills, particularly when towing. I have had everything checked including the radiator out tested, flushed and replaced as there was no problem. After not sorting out the problem I recently realized that this problem started when my mechanic removed my EGR system. My vehicle is a Gen 3 and I towed a 1.5 ton trailer for over a year / 30 000km before this started happening. It may be purely coincidence that it started after removal of the EGR, but does anyone know if removal/blanking of the EGR can lead to heating issues, there is some info on the web but it is not very conclusive.
Cheers

I hope I am not the bearer of bad news, but my 2001 DID Auto (280 000km at the time) when towing an Echo4 uphill started to overheat in exactly the way described in this post - temperature rises quickly uphill and back to normal once you are over the hill. It was due to a cracked head. New head and pistons at 296 000 km and problem solved.

rmh wrote:I hope I am not the bearer of bad news, but my 2001 DID Auto (280 000km at the time) when towing an Echo4 uphill started to overheat in exactly the way described in this post - temperature rises quickly uphill and back to normal once you are over the hill. It was due to a cracked head. New head and pistons at 296 000 km and problem solved.

Was there an overheat situation that might have caused the cracked head? Mine also rises on long hills while towing or in low range going up steep hills on trails. Otherwise she runs perfectly.

Hi, my car has a long story behind the overheating. I was loosing water so i thought it was the head and had it removed, tested and replaced while on a trip in Zambia. They did a bad job and had it all redone by my local mechanic who had it skimmed as a pre-caution when it was tested (nothing wrong witht he head on both occasions). Since then i have not lost any water, but it was at this time that he removed the EGR system, and now although i am not loosing water i am having a temperature problem (never had that before even when towing). Recently i read up on EGRs and i see that they can lead to problems which appear similar to a blown head gasket or cracked head (smoke; loosing water; heat etc) if they are blocked or jammed open/shut. Hence my question regarding removal of EGR and if it can affect temperature is not removed properly/completely. Hoping this is something i can look into otherwise i am all out of ideas of what could be the cause of the problem. I am reluctant to put in a bigger radiator (as advised by the local agents) as this is just covering an underlying problem.

Cheers

Revisit the whole "removed the EGR" process. What exactly was done?

EGR is not used at full throttle or high demands on power, for example when towing uphill.

Some basics to check

When is the last time you replaced the thermostat with a genuine one? Ageing thermostats do not open fully restricting flow.
Is your bash plates still there or do you have aftermarket bash plates? The bash plates help create a negative pressure around the engine that helps draw air through the radiator.
What does your ATF look like? A hardworking box because of bad ATF will create excess heat.
What does your coolant look like? Old coolant does not transfer heat as good as fresh coolant.
Is your radiator free of dirt and seeds and mud?
Is your intercooler free of dirt and seeds and mud? A dirty intercooler can lead to high IAT that robs power.
Give your bimetal strip on the viscous fan a squirt of penetrating oil so it can move freely to operate the clutch valve on the inside.
Check the turbo wastegate opening pressure. A prematurely opening wastegate will cause a lack of power, boost and cause possible overfuelling that adds heat to the system.

Hi Marius, thats what i figured regarding the EGR, only used when cruising so unlikely to be my problem, but my last hope at the moment.

Roelf, not sure what was done when the EGR was removed, but the piping over the top was removed and blanked off, not sure if the valve was removed and if the cooling system was bypassed (if thats possible? or necessary?)

Had the thermostat checked not replaced, apparently fine
radiator out, cleaned and refilled at Silvertons PE. Intercooler checked at the same time.
Standard belly plates still on
ATF changed recently
Will need to look into the 'bimetal' strip but apparently viscous fan is working according to Silvertons
Recently had the vehicle in for remapping the Unichip and had the turbo redone so i assume they would have checked the wastegate pressure

So besides lubing the viscous i am not sure where else to look, vehicle has 190k on it so it should have a lot more left in it

cheers

Experienced similar on one stretch on the N9 coming out of Graaf Reinet up those monster hills that seemed to never end. With echo4

I always drop to 4th in tip tronic before gearbox decides as that is usually too late and most momentum is lost.

After some trial and error on way back home I noticed that if i ride the car hard or try get more out of it as it can give the temperature went up. If i climb off the throttle a bit and let it coast on own steam even at 50-60km/h up hills then the temperature stayed normal

Also had new radiator cap before we went off in December

Change the thermostat

Remove the Unichip

Check again.