ac causing diesel pathy to overheat

[dnodog]

this is weird ... i can drive my path flat out, or up hill without the ac on and the temp barely gets to half way..but if i try it with the ac on... it starts to overheat?

I have in a custom made 3 core radiator.if i slow down or am on flat roads..the temp drops back to normal quickly.

[Diesel Boy]

Thats perfectly normal, the A/C condensor sit directly in front of the radiator, and produces alot of heat. Are you sure your viscous fan is doing its job properly??

[88pathoffroad]

Very good point. Check your fan clutch for proper operation first.

[dnodog]

that is a good question? i don't know, but i changed the viscous stuff about 6 nonths ago so it should be. Planning to remove that anyway and add an electrical one as soon as i can find one in a junkyard. Not many pathys on the island, maybe i could get one from a Nissan maxima

[Diesel Boy]

Here's a simple viscous test:

When the engines cold, get a big pastic sheet of some sort (any thing that will not alow air to pass through it will do) and open the bonnet, wedge one end under the bonnet, drape it down over the grille, and tuck the other end in around the sump gaurd area. The idea being to block as much air flow to the radiator as possible. It realy needs to span right out to the corners of the vehicle, covering the headlights etc.

Start the engine and run it on the hand throttle at about 2000rpm, keep a eye on the temp guage, and listen for the fan to come in, it should start roaring and suck the plastic sheet into the grille with a fair bit of force. It is acceptable for the fan to come in just over half way, and switch of again as the temp drops back past/under half way.

 

Let us know what you find happens. My other thought is that it is more than possible the Japanes boys in there airconditioned office didn't think about the heat of the Carribean(sp) when they were giving the cooling system design its final ok. We get NZ new Nissan Navaras, which are the equivelant of the USA Hardbody, and the Utility version of the Pathfinder and Terrano. Over here, and in Australia the TD27t modles of these Navara's come out with a 10" electric cooling fan on front of A/C condensor, providing the cooling system with that little bit extra. On our Japanese imports, the first thing we change is the thermostats, especially on Turbo Charged Diesels, as they straight away start cracking heads and exhaust manifolds. They have a cooler climate than we do here, so i think we use a thermostat that opens fully 10 degrees earlier than what they come over with.

Anyway...................

See what happens when you do the test,

Pete.

Edited February 6, 2005 by Diesel Boy

[88pathoffroad]

You cold do that, or spin the fan by hand while cold, then while hot immediately after shutting the engine down. When cold, it should spin easily, when hot it should be tough to spin by hand.

[Diesel Boy]

Fair comment, but not quite as accurate perhaps???

A sh1t load easier though!!!!!