Hi Guys

Is it possible to a Datsun to run Hotter than usual by changing a Radiator Cap ?, how to check whether the water Pump is pushing water in the correct pressure ?

Thanks
Regards
Sumith

Well yes it is possible. The cap is rated to a temperature or it might just have the pressure it's rated for stamped on it (0.9 bar for instance). The more pressure it can hold the cooler the radiator can be. Does your car have a clutch fan setup or just the direct fan on the water pump pulley? the water pumps are different for the two. As for testing it well I reakon it takes a while because you have to wait for the thermostat to open in order for the flow to be seen easily. Otherwise it's just as simple as running it with the cap off for a few minutes.

Hi DattoMaster

i don't have Cluth Fan setup

Thanks
Regards
Sumith

I don't think the thermostats fail very often but a good way to see how they work is to drop it in some boiling water. Watch it slowly expand.

I do not reccomemnd you remove the thermostat from the system (as some people do) as it also acts as a baffle to ensure the water is cycled throught the entirety of the engine block. It's removal will see the water cycle so quickly (pressurised) that the rear of the block or one side of it will not receive the cooled water that has come from the radiator. This can be damaging particularly if the engine is used frequently at higher rpm.

It is rare that the pump underperforms as it has a steel impellar. As long as you have a taught fan belt there shouldn't be any drop in 'water pump pressure'. If the impellar is missing some fins you may get a lack of flow.

You may also have a cavity or an air-pocket in the water jacket of the engine block, I have only had this once. All I did was run the engine at idle until it got nice and hot turned it off and released and reselaed the radiator cap and this seemed to work (I did this a couple of times).

Hi Guys

Ok tell me for a example you run 100 KM in a very hot day (32 Celcias)about 70-80 KmPH , where should your water Temperature gauge sit , is it closer to H side or closer to C side

Thanks
Regards
Sumith

It must sit in the middle on the temperature gauge or 1mm to the left of the middle mark.

HI 1200GXman

Means Mine has a problem with cooling system operation, what should be checked to rectify this issue

Thanks
Regards
Sumith

1. How old is your thermostat?
2. Is it a genuine Nissan Item?
I would replace thermostat with a new one and also a GENUINE Nissan one. I had problems in the past with non-OEM parts.
Ask for the coolest thermostat because you are in a hot country. That is what I did.

3. Check the condition of your radiator. I would almost guarantee it is blocked due to age. If the core needs to be replaced, do yourself a favor and fit a triple core.
I think this would be the cheapest and quickest solutions. If these don't work, come back to us.

Hi 1200GXman

I think all those are datsun factory parts, any way not sure about , can you tell me is it possible to see the thermostat
by myself if so how ? i have to ask my dad whether he has replaced any of those parts ever before

Thanks
Regards
sumith

well not all will sit to the left of middle above 30deg c and over 80kmh. mine sits between half and h on the factory gauge but only 180-185deg f on my mechanical gauge.

old gauges and sensors loose their calibration and accuracy after 30+ years. where does yours read? also have you thought about a seperate mechanical gauge to test it too?