# a 2.4l 2wd radiator overheating problem!



## nirebeaux (Aug 2, 2014)

ok I have a boiling radiator, I've change the hose on the lower "b/c it was collasping",the theromstat,and now the water pump. on each part replace it had(s) boiling noise. I have a 2000 frontier one owner(me) has 179,000 on it I flush and clean fins on the rad. the temp gauge ran up to Hot one time, other time I notice it go ahalf way of the gauge and goes either just above or below and had the boiling noise. I notice the rad. cap has a spilt in the rubber seal...could that be the problem Or how about the fan clutch? how can you trouble shoot a fan clutch to see if it's inop? Help!!!:|


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## nirebeaux (Aug 2, 2014)

Please.....Im stump!


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## rogoman (Dec 16, 2004)

First make sure that there are no air pockets in the system. There should be an air relief plug where the top radiator hose connects at the head. Jack the car up in front and remove the air relief plug; squeeze the upper and lower hoses to help purge any air pockets. Here are some other possible causes for overheating:

- The radiator may be plugged up.
- If you replaced the thermostat with an aftermarket piece of junk, that could cause a problem. Always use a Nissan OEM thermostat.

The clutch fan should be spinning at idle speed. At higher RPMs it'll be free-wheeling. You can tell by the fan noise and feeling the air flow.


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## BRubble (Jun 22, 2014)

I would get a New Radiator Cap for sure.

If you are looseing Coolant,, I would suspect HeadGasket Damage Possible.

If it is actually a Blockage,, then You can check that by opening up the Drain on the Radiator,, and useing a Water hose to see if it is Free Flowing.

On my '93 KA 24E Engine,, it did have an Air Bleed Screw. It was located on the Top Side of the Engine,, but don't remember exactly were it was at. I think that it took a 10mm Socket to fit it,, but that is total recall from way back.

The Service Manual,, will let you know if there is an Air Bleed Screw on your Engine.

On my '13 4.0, there is no mention of an Air Bleed Screw when changeing the Coolant.

On my ka24e engine,, there was also a Block Drain,, that I took out when I changed the Coolant,, but it was Bad Bugger to get back in,, if I remember correctly.

If you do find the Radiator is Blocked,, I would probably opt for a new one,, instead of being Rodded Out,, since the Radiator is almost 15 year's old.


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## nirebeaux (Aug 2, 2014)

ok thank you all forr the replies, Im gonna test drive the radiator cap 1st. then go from there. Ill keep you posted.


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## nirebeaux (Aug 2, 2014)

Ok replace the cap, the boiling noise has disappeared, but the gauge does move up and down but not dramatically. So guessing fan clutch next?


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## smj999smj (Jan 1, 2006)

A bad fan clutch will only cause it to overheat at low speeds and idling. Assuming you purged out all of the air pockets, drive the vehicle at speeds 45mph and higher. At these speeds, there is enough air forced through the radiator core to provide sufficient coolant, so the mechanical fan isn't really a factor, which is why they put a clutch on them to begin with. If you are overheating at high speeds, then it is likely NOT the fan clutch and you have another issue, more likely a blown head gasket or a clogged radiator.


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## nirebeaux (Aug 2, 2014)

ok thx,I'll be watching close


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## mtippins123 (May 25, 2011)

check your temp sending unit also.


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