High engine temp under load

[Silhouette]

My 4.2tdi has just begun to get hot while towing, particularly on inclines. I think first I will get the radiator flushed.
I owned a Toyota once which had an overheating issue and it was exhausting and never solved so I ended up selling it. I did everything to fix it but pull the head off. I don't want to go down that road again.
I am told that Patrols are known for getting hot when towing, is that true?
It has never faulted before now and Ive owned it for 7 years.
Perhaps I am asking too much as I am pulling 2.5t plus a loaded tray and the days here right now have been 40 degrees+.
What do you think?

[Dales300exc]

Clean the fins in the radiator and see how it goes. Can always upgrade radiators to cool better. Then theres things like exhaust and bigger intercoolers. Lower exhaust temps means lower engine water temps. Plus more power.

[my third 256]

replace thermostat and use only nissan one

[threedogs]

Up grade your radiator to a bigger copper one and fit an OE thermostat

[Stropp]

first job check the viscous hub, it may need servicing so it spins when driving, if it is low on silicone grease the fan stalls and will run hot.

[Rumcajs]

Argh, the suggestions.
Example, does it start to overheat when climbing a hill but recovers quite quickly on flat, downhill run? Under load temp increase could be related to reduce coolant flow through radiator means the radiator is getting blocked either externally (easy to see) or internally ( impossible to check unless dismantled.) Externally blocked radiator can also affect viscous fan thermostatic valve which doesn't get any/reduced hot airflow over it hence it is not engaging when it should. In either case the cooling system is becoming marginal and can't keep up when ambient temperatures or load increases.
The best way to check externally blocked radiator is (if you can there might not be enough space between fan, shroud etc.) is to stick workshop omnidirectional inspection light behind the fins and check from the front how much light is visible. (you can also see the filth stuck among fins).

If the silicon fluid from viscous coupling leaks out it leaves the tell tale traces of dust spots (the oil really attracts dust) near where it leaks. Another option is to check (this is general info might not apply to TD42) when engine is cold (first start) the engine fan should be heard roaring when RPMs are increased and if after hot run the engine is turned off and fan is engaged it will stop with the engine immediately when engine is turned off. If it keeps spinning than it is low on fluid and while still hot it should feel reasonably tight to turn.



Cheers

[Silhouette]

Argh, the suggestions.
Example, does it start to overheat when climbing a hill but recovers quite quickly on flat, downhill run? Under load temp increase could be related to reduce coolant flow through radiator means the radiator is getting blocked either externally (easy to see) or internally ( impossible to check unless dismantled.) Externally blocked radiator can also affect viscous fan thermostatic valve which doesn't get any/reduced hot airflow over it hence it is not engaging when it should. In either case the cooling system is becoming marginal and can't keep up when ambient temperatures or load increases.
The best way to check externally blocked radiator is (if you can there might not be enough space between fan, shroud etc.) is to stick workshop omnidirectional inspection light behind the fins and check from the front how much light is visible. (you can also see the filth stuck among fins).

If the silicon fluid from viscous coupling leaks out it leaves the tell tale traces of dust spots (the oil really attracts dust) near where it leaks. Another option is to check (this is general info might not apply to TD42) when engine is cold the engine fan should be heard roaring when RPMs are increased and if after hot run the engine is turned off and fan is engaged it will stop with the engine immediately when engine is turned off. If it keeps spinning than it is low on fluid and while still hot it should feel reasonably tight to turn.

Cheers

Cheers

^^^ Exactly this ^^^.
It recovers quickly when I lift my foot or after a climb. Tomorrow I will be giving the radiator a work over both inside and out. I am confident that is all it is as the radiator has never had any attention since new.
Thanks for the replies everyone and I will keep you posted with the result.

[guttsy]

thermostat

[Silhouette]

I have pulled the radiator out and it was clogged up with grass seeds so much that I am surprised it doesnt get hot all the time. I havent had the chance yet to load it up but am confident it will be fine now. But we will see.

[threedogs]

Another thing to put on the maintenance list for every 6 month or a visual every service