Jump to content
SAU Community

A Reminder To Check Your Radiator Fan For Cracks And Stress Fractures


Recommended Posts

I was just doing some routine maintenance and discovered some serious stress fractures and 2 big cracks in the radiator fan base. Obviously if this let go it could cause some serious collateral damage (radiator/hose/water pump/belts etc)

Many of our cars are at the age where plastic parts have experienced numerous heat and stress cycles. The radiator fan is one of the most stressed plastic components in the engine bay. Check not only for cracks but discolouration which is indicative of plastic deformation inside the part.

So take 5 minutes to check yours and replace if necessary. It could save you a lot more than the cost of the fan.

post-106570-14193743445125_thumb.jpg

  • Like 1

GKTech make a nice aftermarket fan which also offers higher flow as a benefit.

With mixed results. Certainly not everyone that's used them is happy.

  • Like 1

Cracking on Skyline fans is a common problem (I have more cracked ones than good ones on my cars) and if they let go a high revs they can do some serious damage.

I have seen factory bonnets with major damage from fans letting go - by comparison an aluminium or fibre glass bonnet would just be mince meat with the same impact.

GKTech make an aftermarket fan that moves quite a bit more air volume but it does have its drawbacks. Moving more air generates more noise so it depends on your application. For a normal street car the noise can be a problem but if you have a modified car where engine temps are an issue then they could be the answer to your situation.

With mixed results. Certainly not everyone that's used them is happy.

Mat, 34GeeTeeTee I believe was not happy with the GKTech.

Not enough Cooling.

The Gktech fans are not a fantastic upgrade for RB or VQ engines as Mattgeeteetee and I both found.

The VQ25det fan is visually almost identical to an RB25det fan, so the shroud clearance and depth are essentially the same. I was also using a brand new Nissan fan clutch.

The gktech fan is identical in dia to the stocker

For starters; LUDICROUSLY loud!

The fan could maintain control over the cooling system whilst moving (mid 80's) (even slowly) but as soon as the car was stationary, the fan would slowly lose control of temperature over about 5 min, until it got to around 95 degrees; then it would skyrocket over 110 degrees in less than 30 secs.

This was using a temp reading from the ECU temp sensor on a perfectly bled cooling system with a Nismo thermostat and brand new 42mm thick dual pass Mishimoto radiator. All in mid 20's ambient temperature; so nothing silly at all.

Change NOTHING but the fan and clutch; cruising temps dropped to 78 deg, and never rose above 86 degrees regardless of how long I sat stationary in traffic. As soon as I start moving; temps drop quickly back to the low 80's.

It isn't silent, but no clutch fan is.

Matt's experience was extremely similar to mine.

They obviously work on SR's, but they are 20mm larger dia than the stock fan; tightening the clearance to the shroud may improve flow, but I don't rate them at all.

  • Like 1

Thats interesting Daleo, i have one on an rb25 and am in Brisbane where at the moment, friggin hot, and often is. I've had no oheating issues and it holds the same spot on the temp gauge. I don't have a digital gauge but when i have monitored temp via consult after drag runs, the temp stays the same/ even as with the stock fan. It is bloody loud tho lol. From your report it might ve worth doing more temp datalogging though.

Thats interesting Daleo, i have one on an rb25 and am in Brisbane where at the moment, friggin hot, and often is. I've had no oheating issues and it holds the same spot on the temp gauge. I don't have a digital gauge but when i have monitored temp via consult after drag runs, the temp stays the same/ even as with the stock fan. It is bloody loud tho lol. From your report it might ve worth doing more temp datalogging though.

With regard to the sensitivity of the dash temp gauge; mine (NM35 Stagea) sits in the same spot, 1 needle width below halfway.

It is exactly the same from 73 degrees to 116 degrees.

When bleeding the cooling system the temp spiked briefly to 123 degrees ( recorded as peak hold on Greddy Informeter) and the gauge only rose one graduation.

I believe that the gauge is quite non-linear in the "allowable range" but once you go outside; it ramps aggressively to get your attention.

I have no idea how this relates to the RB gauge.

I would be more curious to see how the GKTech goes on a standard clutch.

Gktech make a CNC'ed billet adaptor to suit the RB Viscous clutch. Around $20 from memory.

With regard to the sensitivity of the dash temp gauge; mine (NM35 Stagea) sits in the same spot, 1 needle width below halfway.

It is exactly the same from 73 degrees to 116 degrees.

When bleeding the cooling system the temp spiked briefly to 123 degrees ( recorded as peak hold on Greddy Informeter) and the gauge only rose one graduation.

I believe that the gauge is quite non-linear in the "allowable range" but once you go outside; it ramps aggressively to get your attention.

I have no idea how this relates to the RB gauge.

I have a Yahsio factory gauge (which uses the ECU sender in the coolant neck) in my car and from about 60 degrees up to about 100 the needle doesn't move at all

Like you, while bleeding it i must've caught a hot air bubble and it spiked to 115 or so and the needle, much like yours hardly moved at all

Take from that what you will, i guess that's why we run aftermarket gauges right? :P

  • Like 1

As for the GKtech fan, like others; I've heard great things for SR's, but not RB's - Stock works perfectly for me, no plan on changing it.

I will however check for cracks or hot spots when i get home after reading this so thanks for the tips!

  • Like 1
  • 9 years later...

I noticed a few cracks in my fan today, which lead me to this post. Has anyone actually seen a fan explode? Is the GKTech replacement still no bueno?

I have seen the aftermath of a rotten old stock fan. It took apart the shroud, wrecked some other stuff (PS or A/C, IIRC) and damaged the bonnet. Not ideal.

Sometimes they die more gracefully. Sometimes they live for years and years looking like they should come apart.

The GKTech fan is not different to how it ever was. At least as far as I know. Whether it is any good or not is more a question of what climate you're using it in. In Canuckistan it seldom gets hot enough for the capability of the fan to matter as much as it does here in Fourex. So you should be able to use it without too much concern. You can always sell it to a driftkid in an S14 if you don't like it.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • My dream is also to have a proper hoist, but I don't think it will ever happen. My quickjack is probably as close as I'll ever get, it really is very good though. 
    • Yeah we keep on in the dailies, it is pretty poor how many animals get hit and the driver leaves without checking....have saved a couple of little ones over the years. Bit of a gruesome job though, pouches generally need to be cut open because they are so tight and often the joey doesn't realise mum is gone so they are still locked onto the teat. I checked the modules in front of the DS wheel where an oil cooler should go.... There is the radar unit - that can go for race use) One of the 2 HX water pumps, the silver cylinder. That needs to be kept but might be able to be relocated But the bad news, the big computer mounted vertically in front of the wheel (blocking any potential air exit) is the electric steering computer. That is required until/unless i do a hydraulic steering conversion, and in CAD based modern car design it is not like I can just pop a big unit like that somewhere else (plus the loom would be too short anywhere else too). So, the passenger side is OK to clear out (just use a smaller washer reservoir, potentially elsewhere), but the DS no beuno
    • Well, all the best with the new camry It was interesting to hear about the UK process, it is generally a lot more streamlined here with a shipping agent looking after all the import side (noting the exact final price can still be a surprise.....) and I've used a few different brokers on the japan (or US) side, and never had any trouble with any of them....luck of the draw I guess. You mentioned you didn't get the auction sheet (understandable since you bought it from a dealer, not auction), but I always try and get hold of that because they are pretty thorough. I've imported 2x R grade vehicles over the years and both were fine, repairs in Japan are pretty thorough compared to here in Oz.
    • BTW I measured the jack I have, it is 70mm at the saddle but you only have about 700 until it returns to 150mm high at the cylinder so it is good but no magic bullet.
    • My experience with Rising Sun Exports Before agreeing to the sale I tried to do as much research as I could (obviously), his Facebook reviews are 98% and he goes Live at least once or twice a week. I contacted 2 people in the UK who had used him for their imports, both had positive feedback. His explanation and talk through of the import process was thorough, answering any query no matter how stupid it was. It felt as soon as the money was sent, communication dropped off. I asked for shipping updates every 2 weeks or so, not wanting to pester him, he never had any updates. I wasn't informed the car had been dropped off at the port, I only found out by his Facebook story. I asked for the photos taken at the port, knowing he would need some for insurance purposes. I received a few 5 second clips and that's it. When asked again, he said his staff had them. Weeks later I asked again, he tells me he doesn't have any, but does have 50 photos from the original advert. I never received them. I eventually got the documents sent via WhatsApp after I mentioned the port was requesting them. I purchased a CarVX report, to find out the vehicle is a Grade R with recorded accident damage, first recorded in 2017 when it was first auctioned. He never told me the grade, then again I didn't ask. His response was "Grade R means nothing, it wasn't chassis damage". Still, I would have liked to have been informed about it. Jon prides himself on being open and honest when it comes to inspecting cars, it's his main job doing so at the auctions for customers. When the vehicle arrived in the UK I noticed a few little cosmetic issues. It's a 21 year old car so it wasn't going to be mint condition. The side skirts are cracked on each corner and the sealant is failing. The front grill on the bonnet/hood isn't secured very well, mounting studs are missing. Both minor things, but again, it would have been nice to be told. During a Facebook Live walk around video of the vehicle, he mentioned it has a front Whiteline anti roll bar/sway bar. While on the inspection ramp, I noticed the stock item has been installed. When first questioned, his response was "the ARB? Switched? Since when, it never had them". Since sending video and photo evidence I've not received a response. I'm probably being over critical of the overall condition of an old car, but all I wanted was honesty (which he claims to have). I'm aware I wasn't his only customer, he's busy doing XYZ but other reviews praise him for great communication with regular updates and photos, I felt I didn't receive the same treatment. 
×
×
  • Create New...