Puma Radiator Options

One thing to bear in mind with overheating issues, is that cooling is also one of the 5 duties of an engine oil. If your oil stays good and clean it probably won't be an issue, but if it gets heavily sooted, it'll run out of detergent, drop sludge & allow deposit build up, resulting in poor cooling internally.

The pattern will be overheating under load, back off the load and it cools down quickly. It can happen with any diesel that gets heavily sooted, but most common in 4.2 Patrols & other pre-combustion type diesels.

Heavy oil sooting can be due to performance upgrades as well as CRD injectors becoming a bit sticky allowing some over-fuelling.

Let me know if you think it might be an issue and I can advise further.

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Originally Posted by Brid

One thing to bear in mind with overheating issues, is that cooling is also one of the 5 duties of an engine oil. If your oil stays good and clean it probably won't be an issue, but if it gets heavily sooted, it'll run out of detergent, drop sludge & allow deposit build up, resulting in poor cooling internally.

The pattern will be overheating under load, back off the load and it cools down quickly. It can happen with any diesel that gets heavily sooted, but most common in 4.2 Patrols & other pre-combustion type diesels.

Heavy oil sooting can be due to performance upgrades as well as CRD injectors becoming a bit sticky allowing some over-fuelling.

Let me know if you think it might be an issue and I can advise further.

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Thanks I actually put injector cleaner in it before I drove it back down to Sydney and the oil was changed only 1500km ago so those two are probably out.

Will check the viscous coupling however after doing some research I am wondering if it is not just the thermostat not opening fully. It would seem that a head gasket would be more prone to general overheating where as this is mainly under load such as climbing hills at high speeds.

It never gets too high at slower speeds. Changing the Thermostat would surely be cheaper than a head gasket....at least to check anyway...... :angel:

I've had 2 thermostats stick open in mine (2007). I ended up leaving the second one that way, thinking it would be better than risking the next one sticking closed.

Gotta be something pretty basic in your case. Definitely worth looking at.

Quote:

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Originally Posted by Brid

I've had 2 thermostats stick open in mine (2007). I ended up leaving the second one that way, thinking it would be better than risking the next one sticking closed.

Gotta be something pretty basic in your case. Definitely worth looking at.

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I don't think its sticking closed as it doesn't happen on the flat, just maybe not fully opening.....

Can't see it being the head gasket. You have had this problem for to long, if it was the head gasket it would have got much worse after all this time.

But the viscous fan suggestion sounds solid.

I was also told "head gasket" but like yours Iain, mine must have been "going" for almost 18 months and 50,000km.

unlikely IMO to be a head gasket unless excessive leaks/ pressure is present in the cooling system at the same time. these engines use a multi layer steel shim gasket, when they 'fail' they are very obvious

diesel engines (especially modern turbocharged ones) are relatively easy to diagnose head gasket issues as the cylinder pressures are so high that even a minor leak has obvious and sometimes catastrophic symptoms.


has the overheating got apparent after the new radiator, or just before it was replaced? did you have any othe engine compartment mods done at the same time, or panelwork to the front? also, altering the aitflow under the vehicle can sometimes reduce the efficiency of airflow out from under the engine.
jc

And also if you are running a radiator fan with no shroud, it will have very little efficiency.You will have no end of overheating problems.

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Originally Posted by scarry

And also if you are running a radiator fan with no shroud, it will have very little efficiency.You will have no end of overheating problems.

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100% yes. hence my comment about panel work etc. i have seen seemingly useless looking bits of rubber and plastic left off vehicles after body repairs cause overheating problems as they were there to block off escape routes and direct air through the rad at speed.

jc

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Originally Posted by justinc

unlikely IMO to be a head gasket unless excessive leaks/ pressure is present in the cooling system at the same time. these engines use a multi layer steel shim gasket, when they 'fail' they are very obvious

diesel engines (especially modern turbocharged ones) are relatively easy to diagnose head gasket issues as the cylinder pressures are so high that even a minor leak has obvious and sometimes catastrophic symptoms.


has the overheating got apparent after the new radiator, or just before it was replaced? did you have any othe engine compartment mods done at the same time, or panelwork to the front? also, altering the aitflow under the vehicle can sometimes reduce the efficiency of airflow out from under the engine.
jc

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The heating started when the new intercooler (and portals) was installed, at that point I bought the new radiator which hasnt made any difference. Not its coming into summer and the ambient temperature is rising the engine temp is rising accordingly. For example, as a rough correlation, if I go up Orimbah pass in 20 deg outside temp at 90k/h I get to 100deg, if its 30 deg outside I get up to 110deg.

In other words the temperature of the engine seems directly related to the outside temp and therefor the CAI temp, the hotter the day the closer I get to the cut out and the more I have to back off.

This is only happening under load, the steeper the hill or the more loaded the vehicle the hotter it gets, it cools down to normal operating temp as soon as I back off or level out.

It happened prior to and after the remap.