Patrol Overheating

Hi Errol, I had a similar problem towing my 20ft van back from Melbourne a couple of years ago. When I got back to Sydney I took it to a radiator guy and he found the radiator clogged with all types of gunk. He cleaned it out and I never had another problem.
Cheers
BillM

I believe this is an inherent fault, I have several friends with 4.2TD Patrols, they all overheat when worked hard, they also cool down very quickly once the load is eased.
I think you may find that the cooling system is borderline, as it was in the Terrano II 2.7TDIs.

If you search on the Patrol4x4 forum, back around 2006 you will find NUMEROUS posts I did regarding my 2000 4.2TD Patrol.

The temp gauge used to read almost to the "H" zone whenever I towed our 1200kg Ultimate Camper trailer.

I did HEAPS of things to try and cure it.

In the end I decided to just live with it. Having fitted an aftermarket digital temp gauge for the coolant (and the EGT/turbo....both above and below the turbo!!!) I was sort of comfortable to let it go as high as 118 degrees C (which is the actual temp I was reading when the standard gauge was reading almost "H").

One annoying factor was that the air conditioning would switch off at around 105 degrees. I "fixed" that by disconnecting the wires from the plug in the bottom radiator tank, passenger's side. There was a similar plug/switch arrangement on the driver's side of the bottom tank....this was designed to turn the air-con FAN back on when the temp got a bit higher in an effort to force more air through the radiator.

The end analysis was that the good old 4.2 was never designed to have a turbo bolted on to it..... It was basically a light truck/tractor motor and the water galleries simply aren't big enough to "collect" enough heat from the block and as such the heat transfer that the radiator is supposed to do wasn't possible.

I fitted a PWR radiator with about double the capacity.....waste of $1,100- that was!!!

Errol, Yes, if timing is out, it can over heat, but would probably have other symptoms also. I presume you have checked the cooling system and all ok? Do you tow in 5th or 4th? Towing in 5th can over fuel it and also by keeping the foot down and not changing gear when going up hills it will also over heat. Do you have an EGT Gauge? If not, may I suggest you fit one and drive with an eye on it. Amazing to see the EGT's drop as you change down a gear as you go up a hill rather than lug it. Do you have an extra water temp gauge? If not, may I again suggest you fit one. Amazing to see the movement of it compared to the factory gauge. As your EGT's come down, so does the water temp. I think you may be under whelmed if you sell it....... If all else fails, high flowed turbo and 3" can work wonders.

Errol, as Roachie said, the factory gauge is only about 120 degrees when at hot, it is a very misleading gauge. I personally think that every turbo diesel should have an EGT gauge from the factory, but the bean counters win, so no gauge. Good luck with your trip.............

Hey Errol
have the same motor and had trouble towing here in the pilbara - may i recomend talking to the guys at united diesel in perth they fitted a cross country intercooler and a an aftermarket hi output radiator fan - resulted in 10 deg engine temp drop and 100 deg egt temp drop - needless to say very happy
Get Out and Get Dirty
Cheers
Chappy

hi,
Improvement in a cooling system

clean internally cylinder block 2-3 cups of corroded metal is not uncommon
clean internally factory radiator
new thermostat around 85-92 cel
Many original industrial radiaters have to be changed to a larger unit from new , 4x4 are no different
No restriction to radiator air inlet bull bars lights etc
bore holes in bullbars 3-4 inch round
Increase viscous fan drive by adding fluid

Fuel system
pump and injector condition --need to be run on test bench

Check compressions and for a blown head gasket

Up grade intercooler

swamp

Hi Errol
When i had my 4.2 i put a 3 inch exhaust and a larber PWR Alloy radiator.....went heaps better, towed better and temp remained normal.
I now have a newer prado that tows great, is comfortable and drives like a car......I would have my 4.2 back in a heartbeat though.....reliable as the sun.
Cheers
Ev

I used to pop the bonnet and slow a little when towing a 2.5 ton van and the guage dropped instantly. Then when back home had the radiator serviced and no more problems on my 1999 td42 patrol

Thoroughly flush and clean the whole cooler system and refill with a 50% water and coolant mix.

This was a common fault with a lot of earlier vehicles and that was a common cure



Ron

This may be worth checking out if all else fails.

Another common cause of turbo 4.2s overheating from memory is a tiny banjo filter at the bottom of the injector pump where the fuel line goes in. Tends to block up as it is rarely serviced. This seems to cause the vehicle to run lean - (lightish smoke from exhaust and hotter combustion temp).

Not a well know fix as many people put up with it but this has helped quite a few reduce running temps.

Errol - Oil does a heap of work cooling the engine - as well as lubricating it.

If you increase the size of the sump substantially, and fit an oil cooler (or even just a finned sump), you will more than likely find the cooling problem comes under control.

It also pays to ensure the dipstick is the correct length, and the current oil level is correct.

I have seen figures of 9.2 and 10.5L for oil capacity for these engines, so I don't know which is correct, or whether later engines may have increased oil capacity from the factory.

If you can add 3-4 litres to this standard sump volume, it will increase the ability of the oil to dissipate the engine heat.

The 4.2TDi Nissan engine produces 118Kw (158HP) in standard form. I have a 165HP, 6.5L engine in an Isuzu truck, and it holds 13.5L of oil in the sump.
It doesn't overheat, even when grossing more than 10 tonnes on a stinking hot day. You'd be grossing at least around 5.5 tonnes with the 'van in tow?
You're using the Nissan engine as a truck engine, it needs truck engine oil capacity.

Cheers, Ron.

Never tried it , but wonder if that Evans waterless coolant might help you.

Quick test try it with the bonnet unlatched so more air can escape from the engine bay. A lot of cars have these symptoms because it just cant get the air out of the engine bays because they are so cluttered

Errol
Try putting a 3mm spacers between the bonnet and the bonnet hinges , it will allow engine heat to escape from the rear of the engine bay by creating a gap past the rubber seal , a lot of vehicles try to cut down engine noise but do not have sufficient air flow to cool properly under load
A cheap alternative to a lot of expensive fixes , had a cruiser ute with 2H motor and it would overheat in hot conditions with A/C on , why would you want A/C on in hot weather ? once I cracked the seal on the rear of the bonnet , there was no more problem
Best of luck
Mick C