Welcome, if your going to hang around after your question is answered why not go into the newbies section and introduce yourself.

In the General Patrol Discussion section archives there is a long ongoing thread about overheating 4.2's.

 

I'd be sacking that service shop if they can't notice the complete lack of electronics on an old TD42. Sounds like all they know is how to plug a scanner in and hope it tells them all.

I would be concerned about checking earths as the Patrol is known to have crappy earths and there are many threads on here about adding additional earths and improving the original ones.

The aftermarket thermostat would not be high on my list to accuse, that's all mines had in it from the previous owner and the one I have changed and no issues. Neither my factory gauge or aftermarket one show any adverse signs of operation due to the thermostat.

The fan hub if not genuine would be a place I would be looking at.

As would the factory temp gauge itself. They are notoriously vague and designed that way by the factory. I would be putting a good aftermarket one in so I could see accurately what is actually happening and when. Even if you mount it temporarily if you are against aftermarket accessories like that.

 

Many thanks festerGU.
Have invested in infared thermometer to check various locations for temperature, keeping a log as I go. Perhaps you could advise a recommended coolant to use in the cooling system.

As I live in Adelaide Metro I spoke to RAA technical guys, it was they that suggested the infared gizmo just to prove out what was happening. To be honest I am looking for a new service shop.
I am not adverse to fitting an aftermarket temp gauge as long as I can fit it in a good place to read. I note the thermostat body has an unused plug that I can remove to fit the sender unit.


I will go into the archives and follow the overheating threads to see what I can learn.

 

I second what festerGU just said . . . first thing to do is get a good accurate temp gauge as the original isn't worth the space it takes in the dash.

 

The coolant question is about the same as the oil question. I would just say buy good quality that meets your specs and mix it with at least demineralised water. AND ignore their stupid long life recommendations. Change it every couple of years, even yearly. It's cheap.

I'm currently using Nulons Long Life Blue. Mine previously had unknown green when I got it. both seem to do the job. In other cars I used both the Nulon Red and Toyota Red.

I had my temp gauge plumbed into the top of the thermostat housing but it annoyed me that it didn't read anything till the thermostat opened so I've since moved it to the spare port below the thermostat where the 2 factory sensors are.

Can't say I put a lot of trust into those infrared thermometers and you can't track what is happening on the road with one which is where you really need it.

 

Hi Brian, I think fester deserves the "Thanks" more than me, he's put in all the info, I've just agreed

 

Hi Brian,

I have a friend who had an overheating problem with his 2006 TD42T similar to what you describe. Tried all the things one would expect - radiator, thermostat etc, but problem persisted. Eventually the problem was tracked down by a reputable 4WD Workshop to being stretched head bolts. Got them sorted and all good since.

Good luck with yours.
Regards

 

How did the head bolt threads stretch in the first place?

That shouldn't happen unless the same bolts have been taken out and then re-installed in my experience. Even then it's pushing it.

Blown head gasket yes but stretched head bolts?

Franky.

 

Many thanks to all for suggestions.
Took the GU to an independent radiator guy (an old fart like me). Explained the problem.
He took the cap off and said coolant is the problem.

Booked the GU you in for several days later and sure enough coolant was contaminated, formed into gel and blocked 85% of the core. The core was rodded and cleaned and everything put back together for an alkaline flush. The system was refilled with genuine Nissan long life coolant and handed back to me.


Next day about two hours of hill climbing out the back of Adelaide and the result was as sweet as could be. Only downside other than hole in the wallet is the heater now is not as hot but would prefer that to the alternative.

Now on the hunt for a good digital temp gauge as we have a 2,500 km round trip coming up at the beginning of October. Also looking for a good mechanic in the southern area of Adelaide.

Once again thanks to all for the advice and help. Will be checking in regularly.

 

TD42T Overheating problem.

Thought I would post the link to the video the radiator guy took for me.

https://drive.google.com/file/d/0B7c12DSOqI-YQmJVdmx6WndxMHc/view?usp=sharing

 

So it would seem that the coolant in isolation was not the problem but the fact that since the new rad was put in different types of coolant have been mixed together. That is the normal cause of coolant gelling or foaming.

I'm not sold on the idea of cooling system flushes but I do use them when changing coolant and I don't know what was in there before. I just use them for a shorter period of time more as a neutraliser than a cleaning flush.

 

Hi Guys
Have not posted much of recent, but have persisted with fixing the overheating.
Fitted an aftermarket Inter-cooler from HPD in Adelaide ( TD42 99-03 Pro).
Then had the engine dyno tuned by local shop who understood the TD42T. Resulted in 30% improvement in power and much sweeter running.
Am now towing the 2850 kg of caravan confidently with motor running much cooler.