Pajero Sport Gen 2 Overheating Under Load

[Waimaw]

Hello guys ! im New here,
I have a Pajero Sport Gen 2 2012, 4D56(not High power)
When under load , hard Acceleration for 10-15 minutes or going uphill, the coolant temperature starting to rise. Then im driving normally or let it stay at idle, the temp goes back to normal. the ODO is 105000 km now and I had this issue since ODO at 60000kms.
When I had this issue first time going uphill, the water has boiled. I let it run at idle then it cooled down quickly.
The dealer had changed the thermostat, and a coolant temp sensor( I don’t remember which one- the one connected to ECU or the gauge) and refilled the silicon fluid of the viscous coupling.
But still when the engine started to run under load or going uphill for 10-15 minutes, the temp rises.
Since the first time it overheated, I didn’t let my temp gauge rise to red area till now.
I flush and refill coolant every 30000kms, and there is no visible debris or rust. i ve done the bubble test and there are no bubbles coming out from the radiator and no loss of coolant.
At 90000kms I ve replaced the radiator fan viscous coupling. Still didn’t change the water pump and pressure cap.
I ve have fitted a 12inch Spal high performance cooling fan for extra cooling ,and it helped to cool down quickly but still the temp rises under load.
I ‘ve fitted a GFB electronic boost controller(running 16-17psi), GFB Blow Off valve, Evo X intercooler, and Racechip S tuning chip(connected to the commonrail pressure sensor)
I know that the installing a tuning chip could cause engine to overheat , but this heating issue happened before I Install these modifications.
Ive changed everything except the water pump and the pressure cap. Can you guys pls help me out to get this thong fixed because the opinions of you guys are my only hope now.

[KurtG]

I’m not familiar with the Pajero Sport but I am aware of an engine overheating issue where Mitsubishi have had to replace engines. Was some kind of recall or something to that effect.

Maybe yours suffers the same fate?

[KurtG]

Double Post

[Waimaw]

I’m not familiar with the Pajero Sport but I am aware of an engine overheating issue there Mitsubishi have had to replace engines. Was some kind of recall or something to that effect.

Maybe yours suffers the same fate?

Oh! is that true?
thanks for the reply Kurt.

[Hugen0408]

Hi.
If I may. I'm not going against Kurt experience. Also, At 60000 km its a bit early for the water pump to go?

I would suggest to change the radiator cap with the correct spec from the agents. It's worth a try cause the part is quite cheap. Sometimes the rubber seal is thin and soft from the heat. The spring could also be broken. Let the vehicle temp cool down completely, unscrew the cap and just check the condition. At times the cap don't even show real signs of fatique and fails to do its job anyway.
Remember, it's a part that we don't actually think about cause it tells us never to open when hot. And it's common practice to just fill up the plastic container with coolant to the max mark.

I honestly hope you come right.
Best Regards.
Hugen

[4ePikanini]

Make sure there is no mud or debris in radiator.

Change the thermostat with a genuine one.

Also check egr valve. If its stuck open the exhaust heat may overpower the cooling system.

Sent from my S60 Lite using Tapatalk

[Waimaw]

Hi.
If I may. I'm not going against Kurt experience. Also, At 60000 km its a bit early for the water pump to go?

I would suggest to change the radiator cap with the correct spec from the agents. It's worth a try cause the part is quite cheap. Sometimes the rubber seal is thin and soft from the heat. The spring could also be broken. Let the vehicle temp cool down completely, unscrew the cap and just check the condition. At times the cap don't even show real signs of fatique and fails to do its job anyway.
Remember, it's a part that we don't actually think about cause it tells us never to open when hot. And it's common practice to just fill up the plastic container with coolant to the max mark.

I honestly hope you come right.
Best Regards.
Hugen

thank you Hugen for the reply.
changed the radiator cap immediately after i saw your reply. lets see what happen

[Waimaw]

Make sure there is no mud or debris in radiator.

Change the thermostat with a genuine one.

Also check egr valve. If its stuck open the exhaust heat may overpower the cooling system.

Sent from my S60 Lite using Tapatalk

thank you for the reply Pikanini.
i did change the thermostat before, but no luck
and also i ve cleaned the EGR. So, no soot build up in EGR valve.