Clutch Fan Problems

[flagger]

Ok, my r32 gtst is overheating like a cat on heat now, and i just went down to a radiator specialist. turns out the clutch fan can freely move when the engine is turned off, so he reckons its stuffed. It still does spin though when the car is on, but it obviously isnt getting enough airflow.

The problem is now, trying to find a working replacement clutch fan. its bloody hard finding one for a rb20. do the rb26 or rb25 ones fit up ok? would i just need the hub?

The other option i could go is a thermofan i spose, but im worried about hooking up a controller. dunno what to do about all this

[Kinks]

are you for real..

take it to someone who's heard of a clutch fan!!!

when cold, the fan is driven by a viscous coupling so it spins, but not with any force. it will move a nominal amount of air through the radiator but if the car heats up the clutch should lock, and then the fan is driven directly proportional to engine revs (you should probably be able to hear it, although the difference is less with more modern cars. My R31 sounded like a falcadore when the fan kicked in, R33s are much quieter owing to better technology in the shape of the fan blades).

If your car is overheating these are the possibilities:

1) Shagged water pump

2) Blocked thermostat

3) Blocked radiator

4) Clutch fan not locking up properly.

Does it overheat on cruise or just when stationary?

[flagger]

it overheats on cruise.

when i brang it down to the rad guy this morning, the system was pretty warm/hot. the needle on my temp gauge was halfway up.

i had the engine replaced 3 months ago by mercury after a *ahem incident*, and it overheated on day 1 i got it back. took it back to them, had it pressure tested and it came back fine. they put it down to a bubble in the system. then for 2 more months it only overheated once more, so i put it down to a bubble in the system too (i bled and flushed it after it the 2nd time).

However the last 2 weeks its just been getting worse and worse, where its at the stage now whenever i go for a 20+ min drive it will overheat and i have to turn the heater on full to keep it at normal temps

also i just rang around some places, 1 wrecker wants $175 for a clutch fan hub, and moorooka nissan said there are no hubs in australia, but can get one from japan for $423 not really sure if the 2nd hand price is fair or not

another question...is the sr20 hub a direct replacement, or a rb25/26?

Edited August 19, 2006 by flagger

[Syphon]

1) Shagged water pump

2) Blocked thermostat

3) Blocked radiator

4) Clutch fan not locking up properly.

I would be looking at Option numbers 2 or 3 first before changing the clutchfan.

If you have no idea how old the radiator is, and it looks a little tired, chances are it's due for a cleanout. Take it to a decent radiator place and have them do a proper cleanout and flush on it, none of this jam a hose through it and hope its ok

Otherwise, its possible you have a sticky thermostat, which could explain why its only overheating every now and then. Occasionally frees up and runs fine, but sticks most of the time...

Possibly then look at clutch fan...

Does it only overheat when stationary or at speeds below say 60, once on the highway it cools down? Suspect clutch fans, and blocked radiators seem to show similiar symptoms, so can be hard to judge.

[flagger]

it doesnt overheat when idle. usually overheats when i load the engine up, say by boosting or going up a hill for a short while. ie. last tuesday night, i was going down ipswich motorway, temp was fine, then i gunned it in fourth for about 20 seconds, and the temp guage was 3/4 the way up. when i pulled over, the coolant was boiling

thing is im getting a kit put on this monday, so i wont be getting the car back till tuesday. so i cant do much till later in the week. i guess ill get a radiator place to rod clean it out and replace the thermostat. would radiator places carry the right thermostat for a rb20det?

cheers for the help so far

Edited August 19, 2006 by flagger

[Kinks]

that points to a basic cooling system problem. blocked radiator/thermostat or f**ked water pump.

clutch fan will have no influence at cruise speeds, so forget that. especially in 4th

[Bl4cK32]

i agree ^

I replaced the clutch fan hub on my car with a craig davies hub i bought from Sprint auto. It had on the box Skyline r32, r33 and vl holden (rb30et) It cost $130 @ trade price. Just a heads up incase...Flush the rad (including heater box core) + system, replace thermostat and cap, bleed system. If that fails replace clutch...let us know how u go:)

[flagger]

well ive already flushed and treated the system (including core). what im gonna do is drop it into a radiator place sometime this week, get them to rod clean the radiator and change the thermostat and see how it goes. if theres still probs then its time for a new hub.

good to know the rb30 and rb25 hub fits on fine too

[Bl4cK32]

thats the rb30et (turbo) one, not the std rb30e as the shaft is different. Just swap your fan over if u have to replace it.

[Syphon]

And just so you know, the thermostat is the same as used on an RB30 aswell so you won't have a problem sourcing a new one, don't buy anything but a genuine nissan thermostat, the rest are junk IMO

[flagger]

excellent info guys. thanks

syphon, so its the same as the one on the rb30e?

[Syphon]

flagger, I am not really certain if the part numbers are identical nor the temps they both open at but I know that they both fit.

If you like I can find out for certain tomorrow, as I do have a contact at Nissan who will suss it out for me. From memory though, the rb30 thermostat opens at 76.5 degrees or there abouts. No difference in thermostat as far as i am aware between rb30e and rb30et, so i could not see a problem running the 30 thermo on a 20 etc.

[flagger]

If you like I can find out for certain tomorrow, as I do have a contact at Nissan who will suss it out for me.

that would be awsome if you could double check for me

[Syphon]

No worries, will post up tomorrow with some more information.

edit* just done some quick searching on these forums and it appears rb30 and rb20 thermostats are identical heat range, being 76.5 degrees.

Part number for the rb20det unit from an R32 is 21200-42L05 apparently..

I can confirm a part number for the rb30 unit, i do have some in stock at work as far as i know. Can check a price for you and let you know.

Post back tomorrow

[Syphon]

flagger

RB30 thermostat part number is 21200-42L01.

[flagger]

awsome, thanks so much for your help

[flagger]

ok, just as a follow, i took my car in today to cairncross radiators at albion. turns out the radiator was 90% blocked. since they had already pulled out the old radiator and removed the endtanks, I just got them to install a new radiator (koyo 25mm alloy). Apparently ive been running without a thermostat as well, only the housing was there. they couldnt source the right thermo (they tried to fit a rb30 one in but couldnt), so im still currently thermostatless.

so i got it back, and gave it a bit of a thrash on the way home, and the stock temp gauge stayed in the centre (took a while to warm up of course). so it appears to be ok. dunno if i can be bothered sourcing a thermostat.

thanks for all your help guys.

Edited August 24, 2006 by flagger

[Bl4cK32]

u could be using more fuel if u dont run a thermostat.

*my own opinion*

Doesnt the ecu use the temp sensor to decide when the cars warmed up, and puts in less fuel??

*flame away* but thats my thoughts, as the car will take longer to warm up without the thermostat.

[flagger]

for sure...ive noticed i use more fuel when i do more small runs between cold starts. kinda sucks. but i dont drive it that much, about 100-200km a week.

[B0oStEr]

Don't run around for too long without a thermostat or your motor will wear out very quickly.