R33 Temp raises on idle

[Blakeo]

Hi guys, I can't stop my R33 from raising in temp on idle. On cruise it will sit on thermostat 78 degrees, however once idling it will very slowly climb had it up to about 83 degrees idling for about 15 minutes and if I left it longer would have kept raising. If aircon is on it will sit on 95 degree idle, which I've had up to 105 degrees and will not go down unless driving. 

This leads me to believe that its not getting enough air to cool the radiator at idle. Radiator has been replaced with a brand new Mishimoto to try solve the issue, also has been running a GKTech fan (have never tried oem fan as wouldn't clear the cross over pipe when installing the intercooler). I think the GKtech should be better than the oem fan anyway as apparently it pulls 30% more air. 

Car also has a brand new genuine clutch fan, new oem water pump and the coolant has been flushed and replaced with the correct coolant and was vacuum bled to ensure no air. 

I am at a lost as to why it is gaining temp, my friend suggested I may have the gktech fan on the wrong way around but when I put my hand behind the fan its pulling air towards the motor which I believe is correct because you wouldn't want the fan to push air against the rad instead you'd want it to pull it thru?

Thanks.

Edited April 27, 2019 by Blakeo

[KiwiRS4T]

So are you running a brand new clutch fan or a GKTech fan? If the latter does it fit nicely with the OEM shroud?

[GTSBoy]

The GKTech fan is absolutely NOT better than the RB fan.  They might claim that it is better than the SR fan (that it was designed to replace), but nearly every report of one used on an RB has been negative.

Also, many brand new fan clutches to suit RBs are pure shit. A bunch of them are way too tight, making the car sound like a Patrol all the time, and some are too loose (or more to the point, need higher temperature to make them work) and the car won't get enough fan flow when it needs it.  I went through the (usual) Dayco offering, and at least 3 others of various origin before giving up and putting a known good OEM one on my car.  All were either too noisy or no damn good at cooling (except the Nissan one).

[admS15]

Put genuine nissan fan back on and drive off into the sunset. Modify intercooler setup to allow fitment.

 

Brand new ones can be purchased from kudos Motorsport for around 170 if you can't find a good 2nd hand one that doesn't have micro cracks on it.

 

 

[georgev]

I had the exact same problem on my R33 GTR after I fitted a Mishimoto radiator and fan.  Problem was solved when I put a factory fan back on.  They are big and flow a lot of air, and they are always on.  Mishimoto cap was faulty also and had leaks from the rad filler.  Others have said that the Mishimoto rads are crap and always give a hot idle.  I would never buy another another one.

[Blakeo]

21 hours ago, georgev said:

I had the exact same problem on my R33 GTR after I fitted a Mishimoto radiator and fan.  Problem was solved when I put a factory fan back on.  They are big and flow a lot of air, and they are always on.  Mishimoto cap was faulty also and had leaks from the rad filler.  Others have said that the Mishimoto rads are crap and always give a hot idle.  I would never buy another another one.

Do you mean you had a gktech then went back to factory fan blade and it fixed it?

[Blakeo]

On 4/27/2019 at 1:13 PM, GTSBoy said:

The GKTech fan is absolutely NOT better than the RB fan.  They might claim that it is better than the SR fan (that it was designed to replace), but nearly every report of one used on an RB has been negative.

Also, many brand new fan clutches to suit RBs are pure shit. A bunch of them are way too tight, making the car sound like a Patrol all the time, and some are too loose (or more to the point, need higher temperature to make them work) and the car won't get enough fan flow when it needs it.  I went through the (usual) Dayco offering, and at least 3 others of various origin before giving up and putting a known good OEM one on my car.  All were either too noisy or no damn good at cooling (except the Nissan one).

I just bought a brand new one from my local Nissan dealer at a cost of $600+ I will be going back tomorrow to order a oem fan. 

Only reason I went gktech was to clear cooler piping but that is stupid. 

Thank you. 

[georgev]

2 hours ago, Blakeo said:

Do you mean you had a gktech then went back to factory fan blade and it fixed it?

Not gktech.  I bought a Mishimoto radiator and a Mishimito thermofan together.   I still have the rad but I replaced the thermofan with an original fan and my temp problem went away. 

[niZmO_Man]

If you hold the revs at say 3,000 rpm while idling, does the temp go down? Can you hear the fan?

[Blakeo]

59 minutes ago, niZmO_Man said:

If you hold the revs at say 3,000 rpm while idling, does the temp go down? Can you hear the fan?

Temp stays the same, yes can hear fan. 

[niZmO_Man]

I had a hairline crack on the radiator end tank (top) on my R31 and it did the same. Airflow + revs reduced the temps, but sitting in traffic made it rise dramatically. The crack got big enough eventually that I could see steam flowing out of it.

Could be a cracked hose somewhere, or radiator.

[JDM33R]

Not sure if you have fixed the problem yet but here is my 2 cents...

I had 5 years of overheating at idle problems with the standard fan with an aftermarket 52mm core radiator. 

The more water your radiator holds the more air needs to flow past it to cool it down. 

It was especially bad on a 40 degrees day and the AC was on, couldn't go far if i wasn't doing a constant 50kmh.

The factory fan decided to seize and spit a blade into the radiator so i decided to try a smaller radiator and bought a 42mm core radiator.

I now have a measly 12" electric thermo fan on the engine side and a 10" fan on the other blowing through, it sits at 82 degrees with the AC on in any temperatures.... Problem completely gone.

Not saying that is your problem but its worth looking into..

Ok maybe that was 3 cents worth.  

[JDM33R]

Oh and BTW, the items i bought (Radiator and thermo fans) are NOT quality items (Ebay Genuine parts) haha