Overheating Problems

[the ferret]

Depending on the model of fan, you can pull them apart and replace the liquid inside I believe, havn't done it, dunno what its called, but you can get it from Toyota,
makes it like new again, I'm not keen on electric fans, where you are you need good airflow most of the time eh, you will need two vials I am told. I'm sure someone on here has done it and may be able to throw more light on the subject cheers.

[Gantos]

I'm not sure what model Nissan you have but I have a 1988 GQ 4.2L petrol model with carburettor that had an overheating problem that had everyone baffled. Overheating problems are the worst kind and difficult to solve sometimes, the GQ 4.2L seems to have more than its fair share of overheating complaints.
In my case, apart from the engine getting too hot especially when the air conditioner was used , it was noticeable that the water cooling system was unusually pressurised which everyone diagnosed as a blown head gasket or warped head or the head going soft, common in Nissan GQ's I was told.
None of these turned out to be the cause and the cause was actually the two carburettor water heating hoses that were original and had never been replaced because they are almost inaccessible underneath the carburettor. One hose comes off the back of the water pump housing and the other comes in up higher, one hose was breathing in air when the vehicle was traveling at speed but not leaking water, it was acting as a one way valve. A traveling air pocket(s) was formed in the head and presumably causing hot spots or interfering with the thermostat.
Once both hoses were replaced, and this was a difficult job, the overheating problem was solved.

Hope this response helps someone else with a similar problem, I was at my wits end and looking at removing the head.

[AB]

Lucky find then Gantos and welcome to the forum mate.

Don't forget to introduce yourself to the community when you get a chance too.

[Mrowka]

Seems to me that cutting new holes in the bonnet and adding new fans are examples of "bandage" type solutions. Like a bandage on a wound, they fix symptoms but do nothing for the underlying problem.

In this case, you are fixing the overheating but not what is causing the overheating.

[gf0012-aust]

re your bonnet comments,
i know other gq owners who have tried lifting the back of the bonnet, in each of their cases, their vehicle ran hotter
reason we came up up with is that air over the top of the bonnet is at high pressure when it hits the windscreen creating an air dam preventing air from escaping from under the bonnet.
as opposed to the air at the front of the bonnet, air hits the front of the car and gets deflected up, creating low pressure at the front of the bonnet

I used to have a range rover with a 351cleveland and C4 tranny. I vented the engine bay heat out the sides via a couple of inlet ducts made from an old chin spoiler - it worked a treat as the engine bay used to get stinking hot.

instead of going for a lifted bonnet at rear and cop the boundary layer issues at the windscreen it might be better to duct to the sides like I did. (eg like the old pontiact trans-ams and current discos.)